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    • 专利摘要:
    Method implemented by computer, system and computer program product to simulate the behavior of a woven textile at thread level. The method includes: - retrieve structural information of a woven textile; - representing each basting with four contact nodes (4) at the end of the two contacts (5) of basting between pair of loops (2), each contact nodule (4) being described by a coordinate (X) of 3d position and two sliding coordinates (u, v) representing the arc lengths of the two wires in contact; - measuring forces in each contact nodule (4) based on a force model that includes wrapping forces to capture the interaction of the yarns in the bastings; - calculating the movement of each contact nodule (4) in a plurality of time stages using derived equations of motion using the lagrange-euler equations, and integrating numerically with time, where the equations of motion take density into account of mass evenly distributed along the threads, as well as the measured forces and boundary conditions. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2597173A1
    申请号:ES201531038
    申请日:2015-07-15
    公开日:2017-01-16
    发明作者:Gabriel CIRIO；Miguel Ángel OTADUY TRISTÁN；Jorge LÓPEZ MORENO
    申请人:Universidad Rey Juan Carlos；
    IPC主号:
    专利说明:

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    METHOD IMPLEMENTED BY COMPUTER, SYSTEM AND PROGRAM PRODUCT FOR COMPUTER TO SIMULATE THE BEHAVIOR OF
    TEXTILE KNITTED AT LEVEL OF THREAD.
    DESCRIPTION
    Field of the Invention
    The present invention is comprised within the field of simulations of the behavior of woven fabric at the thread level.
    Background of the invention
    Woven fabrics are made of threads that are woven in regular patterns, and their macroscopic behavior is dictated by the contact interactions between such threads. Woven textiles are held together by basting threads, in contrast to spun textiles, which are held together by interlocking threads (two sets of orthogonal threads called warp and weft).
    The vast majority of clothing is made of a structure of threads, either woven or spun, and the macroscopic behavior of the fabric is dictated by the mechanical interactions that take place at the thread level. However, most of the fabric simulation models in computer graphics ignore the relevance of such a thread structure, represent the surface of the fabric as an arbitrary mesh, and calculate internal elastic forces either by continuous discrete elasticity models [ Etzmuss et al., 2003] or using discrete elastic elements [Breen et al. 1994; Provot 1,995].
    The thread level models of woven or spun textiles have a long history. In 1937 Peirce [Peirce 1937] proposed a geometric model to represent the crossing of threads in spun textiles. Thread-level models have been thoroughly studied in the field of textile research, initially using analytical thread models [Hearle et al. 1969] to predict the mechanical behavior of textiles under specific deformation modes [Peirce 1,937; Kawabata et al. 1973]. Subsequently, textile research relied on continuous models to simulate the majority of thread deformation modes and complex thread-thread contact interactions [Ng et al. 1998; Page and Wang 2000; Duan et al. 2006]. A certain number of techniques have been developed to relieve the
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    huge computational load of continuous thread-level models, such as the use of multi-scale models that resort to expensive mechanics at the thread level only when necessary [Nadler et al. 2006], or replacing complex volumetric threads with simpler elements such as beams, stringers and membranes [Reese 2003; Mc-Glockton et al. 2003].
    Woven textiles have received less attention compared to yarn, due to the higher geometric complexity, which leads to more involved wire contact interactions. Flexible strips are often used to efficiently represent knotted strands, as introduced by [Remion et al. 1,999]. Flexible strips have also been used to approximate spun textiles in a purely geometric way (see, for example, [Renkens and Kyosev 2011; Jiang and Chen 2005]), sometimes combined with thin sheet models in a multi-scale manner [ Nocent et al. 2001].
    Frequently, wire level models capture the most relevant strains and wire interactions using specialized force models, such as flexible and cross springs to capture transverse deformation and breakage at crossing points [King et al. 2005; Xia and Nadler 2011], shoring elements that act as contact forces between the threads to capture the binding in rupture [King et al. 2005], or a sliding speed to capture the sliding of the threads [Parsons et al. 2013]. As a consequence, these models allow the simulation of real macroscopic behaviors of textiles. However, thread-level models in textile research focus on small portions of textile, often in controlled experiments, and cannot simulate complete clothing under free movements, or the plastic effects of individual yarns such as tearing, fraying, and shedding. of threads.
    Recently, thread-level models have emerged that address these drawbacks in the field of computer graphics. The pioneering work of [Kaldor et al. 2008] was the first methodology capable of simulating complete clothing at the thread level in a traceable time, from baggy scarves and leg warmers to large sweaters. With a focus on the tissues, they modeled the mechanics of the individual threads using non-extendable bars, and computerized thread-to-wire contact through rigid punishing forces and friction with speed filter, allowing to predict the large-scale behavior of the complete clothing at start from
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    mechanics of the fundamental threads. The performance of this methodology was subsequently improved in [Kaldor et al. 2010] reusing linearized contact information when possible, using local rotation linearizations of punishment forces to accelerate the manipulation of the thread-to-wire contact. On the other hand, geometric methods for creating ready-made models at the thread level of many tissue patterns are disclosed in [Yuksel et al. 2012].
    More recently, [Cirio et al. 2014] focused on spun fabrics addressing a different methodology, assuming that the thread-to-wire contacts are persistent over time, even under moderately large plastic deformations. This assumption avoids the need for costly detection of the thread-to-wire collision and contact manipulation, thereby greatly reducing simulation costs. In this document, each thread in the textile is simulated as a bar, introducing additional degrees of freedom in the thread crossings to allow the threads to slide along each other and thus generate complex plastic effects such as tearing, fraying , fractured and frayed edges. Other thread-level models (mainly geometric and analytical) also assumed persistent contact, but did not incorporate the sliding coordinates.
    In [Sueda et al. 2011] a general formulation of the mechanics of Lagrange is introduced to efficiently simulate the dynamics of highly constructed bars, through an optimal set of generalized coordinates that combine absolute movement with sliding on restriction nodules. The persistent contact model designed by [Cirio et al. 2014] constitutes an application of the Sueda framework to the case of two bars in sliding contact.
    With a focus on simulations for woven fabrics, the document already commented [Kaldor et al. 2008] proposes an alternative methodology that describes the individual threads using a bar model, and resolving the contact interactions between the threads. A thread-based model allows the simulation of complex small-scale effects, such as thread-thread friction and slippage, tears, fraying, frayed edges or detailed fractures. [Kaldor et al. 2008] also shows that, with a thread-based model, the macroscopic nonlinear mechanics of clothing naturally arises through the aggregation of structural effects at the thread level. But this method is limited by a major challenge: efficient and robust detection and resolution of all wire contacts.
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    The present invention proposes a representation of woven fabrics using persistent contacts with thread sliding. Discrete separation based on persistent contacts has been used for previously spun fabrics, but the application of these discrete steps to woven fabrics is highly non-trivial. There are fundamental structural differences in the arrangement of the threads in spun and woven fabrics, which produce different inter-wire contact mechanics, as well as different thread level deformation modes. For spun fabrics, the placement of such persistent contacts and therefore the discrete separation of textiles can be inferred naturally from the yarn structure. For woven fabrics, on the other hand, the design of an effective discrete separation of woven threads using persistent contacts while retaining all important degrees of freedom of the woven structure is not straightforward. The definition of force models at the thread level that capture the macroscopic behavior of woven fabrics is also not trivial.
    With the special representation of a woven fabric used in the present invention, the aforementioned problems are solved, reaching robust, fast and efficient simulations, and also being able to simulate much denser fabrics.
    References
    BREEN, D. E., HOUSE, D. H., AND WOZNY, M. J. 1994. Predicting the drape of woven cloth using interacting particles. In Proceedings of the 21st Annual Conference on Computer Graphics and Interactive Techniques, ACM, New York, NY, USA, SIGGRAPH ’94, 365-372.
    CIRIO, G., LOPEZ-MORENO, J., MIRAUT, D., AND OTADUY, M. A. 2014. Yarn-level simulation of woven cloth. ACM Trans. Graph 33, 6 (Nov.), 207: 1-207: 11.
    DE JOYA, J., NARAIN, R., O'BRIEN, J., SAMII, A., AND ZORDAN, V. Berkeley garment library. http://graphics.berkelev.edu/resources/GarmentLibrarv/.
    DUAN, Y., KEEFE, M., BOGETTI, T. A., AND POWERS, B. 2006. Finite element modeling of transverse impact on a ballistic fabric. International Journal of Mechanical Sciences 48, 1,33-43.
    DUHOVIC, M., AND BHATTACHARYYA, D. 2006. Simulating the deformation mechanisms of knitted fabric composites. Composites Part A: Applied Science and
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    10
    fifteen
    twenty
    25
    Manufacturing 37, 11.
    ETZMUSS, O., KECKEISEN, M., AND STRASSER, W. 2003. A fast finite element solution for cloth modeling. In Computer Graphics and Applications, 2003. Proceedings. 11th Pacific Conference on, 244-251.
    HEARLE, J. W. S., GROSBERG, P., AND BACKER, S. 1969. Structural Mechanics of Fibers, Yarns, and Fabrics, vol. 1. John Wiley & Sons Inc, New York.
    JIANG, Y., AND CHEN, X. 2005. Geometric and algebraic algorithms for modeling yarn in woven fabrics. Journal of the Textile Institute 96, 4, 237-245.
    KALDOR, J. M., JAMES, D. L., AND MARSCHNER, S. 2008. Simulating knitted cloth at the yarn level. ACM Trans. Graph 27, 3, 65: 165: 9.
    KALDOR, J. M., JAMES, D. L., AND MARSCHNER, S. 2010. Efficient yarn-based cloth with adaptive contact linearization. ACM Transactions on Graphics 29, 4 (July), 105: 1105: 10.
    KAWABATA, S., NIWA, M., AND KAWAI, H. 1973. The finite-deformation theory of plain-weave fabrics part i: The biaxial-deformation theory. Journal of the Textile Institute 64, 1.21-46.
    KING, M. J., JEARANAISILAWONG, P., AND SOCRATE, S. 2005. A continuum constitutive model for the mechanical behavior of woven fabrics. International Journal of Solids and Structures 42, 13, 3867-3896.
    MCGLOCKTON, M. A., COX, B. N., AND MCMEEKING, R. M. 2003. A binary model of textile composites: III high failure strain and work of fracture in 3D weaves. Journal of the Mechanics and Physics of Solids 51.8, 1573-1600.
    NADLER, B., PAPADOPOULOS, P., AND STEIGMANN, D. J. 2006. Multiscale constitutive modeling and numerical simulation of fabric material. International Journal of Solids and Structures 43, 2, 206-221.
    NG, S.-P., TSE, P.-C., AND LAU, K.-J. 1998. Numerical and experimental determination of in-plane elastic properties of 2/2 twill weave fabric composites. Composites Part B: Engineering 29, 6, 735-744.
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    NOCENT, O., NOURRIT, J.-M., AND REMION, Y. 2001. Towards mechanical level of detail for knitwear simulation. In Winter School in Computer Graphics and Visualization, 252-259.
    PAGE, J., AND WANG, J. 2000. Prediction of shear force and an analysis of yarn slippage for a plain-weave carbon fabric in a bias extension state. Composites Science and Technology 60, 7, 977-986.
    PAN, N., AND BROOKSTEIN, D. 2002. Physical properties of twisted structures. ii. industrial yarns, cords, and ropes. Journal of Applied Polymer Science 83, 3, 610-630.
    PARSONS, E. M., KING, M. J., AND SOCRATE, S. 2013. Modeling yarn slip in woven fabric at the continuum level: Simulations of ballistic impact. Journal of the Mechanics and Physics of Solids 61, 1,265-292.
    PEIRCE, F. T. 1937. The geometry of cloth structure. Journal of the Textile Institute Transactions 28, 3, T45-T96.
    PROVOT, X. 1995. Deformation constraints in a mass-spring model to describe rigid cloth behavior. In Graphics Interface, 147-154.
    REESE, S. 2003. Anisotropic elastoplastic material behavior in fabric structures. In IUTAM Symposium on Computational Mechanics of Solid Materials at Large Strains, C. Miehe, Ed., No. 108 in Solid Mechanics and Its Applications. Springer Netherlands, 201-210.
    REMION, Y., NOURRIT, J.-M., AND GILLARD, D. 1999. Dynamic animation of spline like objects. In Winter School in Computer Graphics and Visualization, 426-432.
    RENKENS, W., AND KYOSEV, Y. 2011. Geometry modeling of warp knitted fabrics with 3d form. Textile Research Journal 81.4, 437-443.
    SUEDA, S., JONES, G. L., LEVIN, D. I. W., AND PAI, D. K. 2011. Large-scale dynamic simulation of highly constrained strands. ACM Trans. Graph 30, 4, 39: 1-39: 10.
    XIA, W., AND NADLER, B. 2011. Three-scale modeling and numerical simulations of fabric materials. International Journal of Engineering Science 49, 3, 229-239.
    YUKSEL, C., KALDOR, J. M., JAMES, D. L., AND MARSCHNER, S. 2012. Stitch
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    meshes for modeling knitted clothing with yarn-level detail. ACM Trans. Graph 31, 4, 37: 1-37: 12.
    Description of the invention
    The present invention introduces a representation at the level of compact yarn of woven textiles, based on the placement of four persistent contacts with sliding of yarn in each basting, the basting being well a woven basin or reverse knitting. This efficient representation of a woven fabric at the thread level treats the thread-to-thread contacts as persistent, thus avoiding costly contact manipulation of all together. A compact representation of the geometry of the yarn and the kinematics is used, capturing the essential deformation modes of yarn loops and basting with minimal cost. Based on this representation, force models are created that reproduce the characteristic macroscopic behavior of woven textiles (force models for inter-thread friction, thread bending, and basting wrap).
    A first aspect of the present invention relates to a method implemented by computer to simulate the behavior of a woven textile at the thread level. The method comprises the following stages:
    - Obtain structural information of a woven textile made of woven and / or reverse point basting, said structural information comprising at least the disposition of the woven textile including the density of the basting (that is, the number of basting per unit length) in row and column directions and type of basting.
    - Apply boundary conditions in a plurality of time stages.
    - Represent each tissue or reverse point using four contact nodes, located at the end of the two basting contacts between pairs of loops, where each contact node is described by a coordinate of 3D positions that represents the position of the contact node and two sliding coordinates that represent the arc lengths of the two wires in contact.
    - Measure forces in each contact node based on a force model, the forces being measured both in the 3D position coordinates and in the contact node slip coordinates, and including the model of
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    forces, at least wrapping forces to capture the interaction of the threads and basting.
    - Calculate the movement of each contact node in a plurality of time stages using derived motion equations using the equations of
    5 Lagrange-Euler, and numerically integrated over time, where the equations of motion take into account the mass density uniformly distributed along the threads, as well as the measured forces and boundary conditions.
    The structural information of the woven textile may also include any of the following, or a combination thereof:
    10 - Density (that is, mass / volume) of the threads;
    - Thread radius;
    - Mechanical parameters for the different types of yarn used in woven textile, including said mechanical parameters at least one of the following:
    • flexion modulus (B),
    15 • the elastic modulus (Y),
    • the rigidity of basting wrap (kw),
    • coefficient of sliding friction (p),
    • mass damping ratio,
    • relationship damping- to stiffness.
    In a preferred embodiment the wrapping forces of each basting contact includes the calculation of an elastic potential V according to the following equation:
    1 2 v = - KW-Yo)
    where ^ is the envelope angle, ^ 0 is the support angle and L is the remaining length of the basting contact (5).
    25 The force model can include bending forces using the calculation of a
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    elastic potential V between two consecutive thread segments [q2, q0] and [q0, qi] according to the following equation:
    V = k
    b
    An
    where kb = BnR2, where R is the radius of the thread, An is the sum of arc length of 5 both segments, and 0 is the angle of flexion between the thread segments [q2, q0] and [q0, qi] -
    The force model can include sliding friction forces using the sliding friction coefficient (g) and the sliding coordinates. The force model can also include stretching forces using the elastic modulus 10 (Y) of the threads.
    A second aspect of the present invention relates to a system for simulating the behavior of a woven textile at the thread level. The system includes:
    - Means for storing data to store structural information of a woven textile, at least said structural information comprising the provision of
    15 woven textile including the density of basting in the row and column directions and the type of each basting; Y
    - Means for data processing configured to:
    Retrieve said structural information and apply boundary conditions to a plurality of time stages.
    20 Represent each fabric or reverse basting using four contact nodes, located at the end of the two basting contacts between pairs of loops, where each contact nodule is described by a 3D position coordinate representing the position of the contact nodule and two sliding coordinates representing the arc lengths of the two wires in contact.
    25 Measure the forces in each contact nodule based on a force model, the forces being measured both in the 3D position coordinate and in the sliding coordinates of the contact nodule, and the force model including at least wrapping forces to capture the interaction of the threads in the
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    basted.
    Calculate the movement of each contact node in a plurality of time stages using motion equations derived using the Lagrange-Euler equations, and numerically integrated in time, where the motion equations take into account uniformly distributed mass density along the threads, as well as the measured forces and boundary conditions.
    A third aspect of the present invention relates to a computer program product to simulate the behavior of a woven textile at the thread level, which comprises a program code usable in computer to execute the steps of the previously implemented computer implemented method. The computer program product is preferably stored in a program support medium.
    Experiments have been carried out that evaluate the influence of mechanical and geometric parameters at the thread level on macroscopic mechanical behavior, observing the characteristic behaviors of stretching, breaking and bending of woven textiles, with manifest anisotrophic, non-linear stretching behavior, and plasticity The efficiency of the method is demonstrated in simulations with millions of degrees of freedom (hundreds of thousands of wire loops), almost an order of magnitude faster than previous techniques.
    Thus, the present invention proposes a representation of a woven fabric using persistent contacts with thread sliding. With this representation, robust and efficient simulations are achieved, since both detection and resolution of the thread-to-wire contacts are avoided. In clothing of complexity similar to those simulated by Kaldor et al., [2010], such as a sweater with more than 56K of basting loops, the present invention achieves a speed increase of 7x (regardless of hardware differences ). But the method of the present invention is also capable of simulating much denser textiles, up to real-world gauges, such as a shirt with 325K loops.
    The present invention is an efficient method for simulating a woven fabric at the thread level, using an efficient representation of woven fabrics that treats the thread-like contacts as persistent, thereby avoiding costly joint manipulation of contacts. The present method uses the compact discrete separation of basting contacts that allows capturing the relevant deformation modes at the wire level,
    reaching complex, nonlinear and plastic effects on a macroscopic scale. The present model can handle any fabric pattern based on reverse point basting and weaving between two threads.
    The present invention achieves efficient thread level simulations of woven fabrics, 5 with high resolution and low computation time, predicting the mechanical and visual behavior of any kind of woven fabric made of woven and / or reverse knitting. The present invention predicts in a robust, real and efficient manner, the behavior of a complete fabric based on the behavior of the individual threads.
    10 The invention provides the following advantages in the textile sector:
    - Reduced costs, increased productivity and greater flexibility in the design and innovation of textiles for the textile industry. The behavior of new textiles can be evaluated on simulated prototypes.
    - Carry out the analysis of textiles to evaluate a wrong design of products.
    15 - Carry out high quality animations of new clothes for the purpose of
    commercialization.
    The invention can be applied in different sectors:
    - Design of textiles for the textile industry.
    - Fashion and dress design.
    20 - Clothing marketing.
    - Automotive sector: textile articles for upholstery.
    - Medicine: textile basting for the manufacture of catheters, etc.
    Brief description of the drawings
    A series of drawings that help for a better understanding of the invention and that are expressly related to an embodiment of said invention, presented as a non-limiting example thereof, are briefly described below.
    Figure 1 depicts several loops of a textile woven in a plain knit pattern and an extension of a 3D basting.
    Figure 2 shows, according to the present invention, the discrete separation of the woven textile of Figure 1 and an extension of a basting with discrete separation 5 with two persistent contacts.
    Figure 3 represents in detail the four contact nodes in a basting.
    Figure 4 represents the flexion angle 0 between two adjacent thread segments.
    Figure 5 represents the basting envelope used in the force model.
    10 Figures 6A-6C show a small piece of textile stretched to the point where the inter-thread friction cannot prevent the thread from sliding and the plastic deformations are evident when the forces are released and the textile returns to its state of repose.
    Figure 7 shows a table with the parameter values used in the 15 different examples.
    Figure 8 represents an example of a non-linear behavior observed when a piece of ribbed textile is stretched.
    Description of a preferred embodiment of the invention
    The present invention proposes a representation of a woven fabric using 20 persistent contacts that is compact and that allows to capture the mechanically relevant characteristics of the wire structure.
    The structure of woven textiles is disclosed in [Kaldor et al. 2008], which provides a description of how the threads are woven together to produce a woven textile and its behavior. An individual thread is arranged in a chain of loops along a row of the so-called row address. These loops are pulled up or down through the loops of the previous row, in a fabric or reverse point respectively. Loops appear stacked in columns above the column address. These loops are pulled up or down through the loops of the previous row, in a basting of tissue or reverse point, respectively.
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    Loops appear stacked in columns in the direction of the column. When the thread reaches the end of a row, it is typically bent back to form the next row. The first row and the last row are woven in a different way to prevent them from loosening, while the beginning and end of a thread are simply tied to the textile. Figure 1 shows several loops 2 of a woven textile 1, woven in a plain knit pattern (which is the simplest pattern, with all woven baskets; other patterns made from woven basins and / or reverse stitches can be considered, such as the clear holy point, which alternates rows of woven and reverse point basting, and ribbed, which repeats two basins of fabric followed by two reverse point basting) and an extension on a 3D basting. Loops 2 run along different rows (3a, 3b, 3c, 3d, 3e, 3f).
    The threads of a woven textile experience multiple different forces, both internal due to its own deformation, and external due to the thread-to-thread contact. The macroscopic mechanical behavior of woven garments is determined primarily by thread-to-wire contact, with three dominant effects:
    (i) Contact in the basting, with threads wrapped around each other.
    (ii) Contacts between adjacent loops when a basting is squeezed.
    (iii) Friction under inter-wire slippage or breakage.
    The macroscopic flat deformation (that is, stretching and tearing) of a garment is dominated first by the resistance to bending of the threads as the loops deform, then the adjacent loops can come into contact, and finally the additional deformation requires the stretching of the threads themselves. When a woven textile is flattened, an elastic energy is present due to the flexion of the yarn and the sheath of the yarn. When the textile is allowed to relax, it experiences some macroscopic deformation. With a pattern of clear holy point, the deformation by flexion produced by the development of the basting is compensated in alternate rows and columns of loops. In a plain knit pattern, the rows and columns are curled in opposite directions. In a ribbed pattern, each pair of basting is curled in the opposite direction, leading to a significant natural compression of the textile.
    The present invention proposes the discrete separation of a woven textile using
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    contact nodes To make a discrete separation of the threads in a woven textile, the minimum set of persistent contacts is identified that allow to represent all the relevant deformation modes of the thread. The textile is discretely separated by placing a nodule on each persistent contact, and calling it a contact nodule. In a contact node, the two wires in contact are represented as an individual 3D point, thus eliminating the need to detect and resolve the contact. The contact node is augmented with sliding coordinates that allow the wires to slide tangent to the contact.
    Figure 2 represents the discrete separation of the textile 1 fabric of Figure 1 and an enlargement on a basting contact 5 discretely separated, defined by two persistent contacts (contact nodes 4) where two wires are wrapped around each other otherwise persistently. In a basting, a loop of one row is passed through two loops of the previous row (for example, loop 2fi of row 3f is passed through loops 2ei and 2e2 of row 3e previous). This arrangement produces two basting contacts 5.
    Figure 3 represents in more detail the loop 2f1 of row 3f forming a basting with loops 2e1 and 2e2 of the previous row 3e. In a woven or reverse point basting, a 2f1 loop of a new row is passed through two loops (2e1, 2e2) of the previous row, covering them and producing contacts between the pairs of loops 2f1-2e1 and 2f1-2e2 , in particular two basting contacts 5. In the model of the present invention, two contact nodes 4 are considered at the end of each contact 5 basting between pairs of loops, thus producing a total of four contact nodes 4 (qo, q1, q2, q3) for each basting of fabric / reverse point. The sliding coordinates U and V of the contact node q0, which will be explained later, are also shown in Figure 3.
    During normal operation of the textile, that is, unless you remove a basting, the two wires in each basting contact 5 are wrapped around each other in a persistent manner. The woven textiles are discretely separated as well by placing two contact nodes 4 at the two end points of each basting contact 5. The discrete separation captures the most important degrees of freedom in a loop, and allows to represent any fabric pattern based on plain knitting and knitting between two threads. The use of an individual contact node 4 by
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    basting contact 5 would lose important loop deformation modes, such as stretching a textile due to the deformation of the loop.
    For simulation purposes, the wire is considered to be formed by straight segments between contact nodes 4. For performance purposes, on each contact nodule 4 a plane is adjusted to the incident segments, the threads are arranged along the normal of this plane, and the resulting points are interpolated using soft flexible strips.
    As shown in Figure 3, the wires are allowed to slide into the contact nodes 4, whereby each contact nodule q = (x; u; v) constitutes a nodule 5- DoF (5 degrees of freedom) , with x times the 3D position of the nodule, yuyv are the arc lengths of the two wires in contact, which act as sliding coordinates. The 3D position of a point within the segment is given by:
    image 1
    (one)
    where
    image2
    is the remaining length of the segment.
    Each loop 2 typically has four basting contacts 5, whereby it shares eight contact nodes 4 with other loops. As a result, a dress with N loops has approximately 4N contact nodes and 20N DoFs. The framework of [Sueda et al. 2011] it is followed to derive the equations of motion, linearly interpolate kinematic quantities along the thread segments and apply the Lagrange-Euler equations.
    The force models that capture these essential contact mechanics in the threads under the compact representation of the thread are now described, demonstrating how they reproduce the desired nonlinearity and anisotropy of woven textiles. The forces applied to the fabric model include gravity, internal elastic forces of the threads, contact forces without penetration between threads, friction and damping. In this design of the specific force models, the key deformation modes of the wire structure that suffer resistance have been identified. In some cases, particularly for the flexion of the wires, the force model groups the effect of both internal and contact forces. This is a crucial aspect in the design of force models with persistent contacts because the lack of degrees of freedom
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    in the normal direction of contact avoids the use of typical punishment potentials or non-penetration restrictions.
    For gravity, thread stretching (governed by elastic modulus Y), and contact between adjacent loops of the same formulations for spun fabrics in [Cirio et al. 2014].
    The present force model includes elastic potentials for two main deformation modes, the bending of the thread and the wrapping of basting, which will be discussed first. Details on sliding friction forces will also be explained later, although similar forces are added to all deformation modes. An elastic force for the preservation of the lengths of the basting contacts will also be described. For damping, the Rayleigh model is used.
    According to the textile literature [Duhovic and Bhattacharyya 2006], the contribution of the dynamic twisting of the threads is smaller, especially in comparison with the dominant forces such as stretching and bending. Therefore, following the general methodology, the twisting of threads is not included in this force model. The pre-twisting of threads, on the other hand, has influence on other thread parameters [Pan and Brookstein 2002]. This effect is captured by varying the flexural stiffness and thread radius accordingly.
    With respect to the bending of the thread included in the force model, given two consecutive thread segments [q2, Q0] and [qo, qi], as shown in Figure 4, an elastic potential V is defined based on the angle 0 bending between the thread segments:
    V = k
    b
    d ^ _
    An
    (2)
    An is the summed arc length of both segments. For small flexion angles 0, the flexural stiffness kb is due to internal forces during thread flexion, and can be defined as kb = BnR2, where B is the
    flexural modulus and R the radius of the thread. For large bending angles or 0, the deformation of the loop leads to contact between loops of different rows or to bending due to bending. This effect is modeled by the increase in
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    flexural kb stiffness after a certain threshold (0 = n / 2, for example).
    To initiate the arrangement of the yarn for clothing, the desired loop density in the row and column directions, the radius R of the yarn, and the geometric shape of a loop (that is, the relative position of the nodules within a loop ) are fixed. In addition, for each basting, it is indicated if it is a basting of tissue or plain stitch. The resulting arrangement may not rest in its initial configuration due to unbalanced bending energies, and clothing may compress and wrinkle when it relaxes. The compensation for the flexion in the form of rest can be done by redefining the densities of the loops as follows: first a 5 x 5 cm rectangular sample with the same mechanical and geometric parameters is relaxed, and the average shape of the loops is recorded after relaxation; then, this form of loop is applied at the beginning of the arrangement of the threads for clothing, redefining the density of loops accordingly. Without bending compensation, a dress shrinks and exhibits unnatural wrinkles. When applying the flexural compensation in the form of rest, the textile piece shows a natural behavior.
    With respect to the basin wrap included in the force model, in each basin contact 5 two wire segments are wrapped around each other, as shown in Figure 3, producing a strain energy. Figure 5 shows the basting envelope in more detail, where q0 and q1 are the contact nodes 4 of the basting contact 5 comprising two segments belonging to two different loops (2a, 2b). The amount of wrap is measured as the relative angle between opposite wire segments around the central axis of the basting contact 5. Given the two contact nodes 4, q0 and q1, of the basting contact 5, the unit vector e between them defines the central axis. An envelope angle ^ is defined between the thread segment from q0 to q4 and its opposite thread segment from q1 to q3, and in the same way for the other two segments [q0, q2] and [q1, q5]. Specifically, the angle between the unit vectors (na, nb) orthogonal to the triangles (8a, 8b) formed by such thread segments and the central axis, acting as a hinge, is computed.
    For each pair of opposite thread segments, an elastic potential V is defined based on the deviation between the wrap angle and a resting angle:
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    1 2
    v = - kwh (Y-Yo) (3)
    where kw is the basting stiffness of the basting, an empirically fixed stiffness, and L is the remaining length of the basting contact 5. After testing different values for the resting angle, preferably n / 2 is chosen for a visually realistic wrapping effect, although other different resting angles can be used.
    The wire segments in the basting contacts 5 have a natural tendency to develop. In the clear santa dot pattern, adjacent rows of loops unfold in opposite directions. However, in the plain knit pattern, where it develops in the same direction, characteristic behavior arises: the textile has a tendency to curl in both the row and column directions. This effect is particularly noticeable in the contours of the textile. In the ribbed pattern, on the other hand, each pair of basting is curled in the opposite direction, leading to a natural compression of the textile.
    The present method also allows the inter-wire sliding forces to be modeled with friction. For sliding friction, friction is modeled according to Coulomb on sliding coordinates using anchored springs. According to the Coulomb model, the frictional force is limited by the amount of normal compression in the inter-wire contact. This normal inter-thread compression for a woven fabric is estimated assuming the static balance of the stretching, bending and wrapping forces of the basting. To estimate the normal force due to bending and basting envelope, the forces are projected on the estimated normal in each contact nodule 4. To estimate the normal force due to stretching, on the other hand, we set nodules along the normal contact to take into account the volume of the thread. The sliding friction is governed by the coefficient of friction g.
    When an end nodule of a basting contact 5 slides, the other end nodule should also slide to preserve the length of the contact basting material and prevent the creation or artificial removal of material. It is assumed that the material length of the basting contacts 5 remains constant. This is forced using an energy of punishment. For a basting contact 5
    between nodes q0 and q1 as shown in Figure 5, with arc length l = u1 -
    19
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    u0 and length L at rest, the energy V is defined as:
    y = 1 _ 1) 2 (4) where k is the stiffness of the length restriction.
    The thread slip is negligible under small forces, since friction keeps the threads in place. However, the sliding can in effect take place under moderate forces, such as extensive stretching. In that case, the sliding produces plastic deformations that are maintained when the forces are released. Figures 6A-6C show an example where a small piece of textile 1 fabric (Figure 6A) is stretched excessively with a stretching force F to the point where the threads slide (Figure 6B), and the plastic deformation is present when the stretching force F applied on the textile 1 is released (Figure 6C).
    The equations of motion are formulated using the Lagrange-Euler equations, and are integrated in time using the Euler iteration of implicit recoil with Newton.
    Large-scale numerical examples of various simulation scenarios of woven fabrics are described below. All our examples were run on a 3.4 GHz Quad-core Intel Core i7-3770 CPU with 32 GB of memory, with an NVIDIA Tesla K40 graphics card with 12 GB of memory. The simulations were executed with a time period of 1 ms, and the values of the parameters used in the large-scale examples appear in Figure 7. With implicit integration, the regularity of the patterns produces a dispersed system matrix with at most 11 blocks 5x5 not zero per block row. The blocks produced by collisions and seams are handled in a glue matrix.
    The examples are as follows:
    - Sweater: A female dancing mannequin is dressed in a sweater made of 56K loops (224353 basting contact nodes). The sweater is knitted in the style of Santa Clara, with seams on the sides of the body, shoulders, sleeve-body joints, and along the sleeves. In the textile industry, basting density is measured as the number of basins per inch, and is called
    twenty
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    Caliber (GG). The simulated sweater has 6.5 basins per inch, a caliber commonly found in real sweaters. The simulation took 96 seconds per visual frame (at 30 fps), just 7 times faster than the methodology of [Kaldor et al. 2010] for a model with similar characteristics (regardless of hardware differences).
    - Sleeveless T-shirt: A sleeveless t-shirt model is used to dress a male mannequin who performs highly dynamic karate movements. The t-shirt has 325K loops (1.25M basting contact nodes), 20 basting per inch, and is woven in a clear holy dot style. This caliber (20 GG) is commonly found on t-shirts in shelves made from carded cotton. The simulation took an average of 7.4 minutes per visual frame (at 30 fps), showing how clothes with resolutions similar to real life can be calculated in a time traceable with the present methodology.
    - Sleeveless pullover: The plain knit pattern produces a curl behavior in the textile, and in the model this effect is captured by the wrapping forces of the basting, showing the curl effect in the plain knit dress. The clothing is a sleeveless wool pullover, with 8750 loops (34416 basting contact nodes). As in a real dress, the effect of curling is particularly visible at the edges of the textile. The lower edge and neck are wrapped around themselves.
    One of the main advantages of this thread-level model is the ability to naturally capture complex nonlinear deformations. Figure 8 shows a force graph of a stretched ribbed textile, an example of nonlinear behavior observed when a piece of ribbed textile is stretched, which appears to be compressed at rest, and with the characteristic roughnesses of the ribbed pattern. The highly non-linear behavior is evident, with three different regimes (10a, 10b, 10c) corresponding to opposite wrapping, flexing and stretching forces. The graph shows the force applied to one side of the textile versus the distance side by side, and highlights the existence of the three regimes (10a, 10b, 10c) during deformation. In the first regimen 10a, the roughnesses are flattened and stretching forces are mainly opposed by basting. In the second regime 10b, the loops are deformed, and the stretching is mainly opposed to the bending of the thread. In the third regime 10c, the threads themselves
    They are stretched themselves. Nonlinear stretching behavior arises naturally when the present thread level model is used thanks to the low level structural representation and force models, but it is difficult to capture using traditional mesh-based methodologies.
    5
    权利要求:
    Claims (7)
    [1]
    1. Method implemented by computer to simulate the behavior of a textile woven at the thread level, comprising the method:
    - Obtain structural information of a woven textile made of woven baskets and / or inverted point, at least said structural information comprising the provision
    woven textile including the density of basting in the row and column directions and the type of each basting;
    - apply boundary conditions in a plurality of time stages;
    - represent each woven or reverse point basting using four nodes (4) of 10 contact, located at the end of the two basting contacts (5) between a pair
    of loops (2), where each contact nodule (4) is described by coordinate (x) of 3D position representing the position of the contact nodule (4) and two sliding coordinates (u, v) representing the lengths arc of the two wires in contact;
    15 - measure forces in each contact node (4) based on a force model,
    the forces being measured in both the 3D position coordinate (x) and the sliding coordinates (u, v) of the contact nodule (4), and including at least the force model sheath forces to capture the interaction of the threads in basting;
    20 - calculate the movement of each contact node (4) in a plurality of stages of
    time using equations of motion derived using the Lagrange-Euler equations, and numerically integrated with time, where the equations of motion take into account the mass density distributed uniformly along the wires, as well as the measured forces and boundary conditions
    25 2. Method implemented by computer according to claim 1, wherein
    The structural information of the woven textile additionally includes at least any of the following:
    - thread density;
    - thread radius;
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    twenty
    25
    - mechanical parameters for the different types of threads used in woven textile, including said mechanical parameters at least one of the following:
    • flexural modulus (B),
    • the elastic modulus (Y),
    • basting wrap rigidity (kw),
    • coefficient of sliding friction (p),
    • mass damping ratio,
    • stiffness damping ratio.
    [3]
    3. Method implemented by computer according to any of the
    preceding claims, wherein the structural information retrieved from the woven textile includes the wrapping stiffness of the basting (kw), and wherein the wrapping forces at each basting contact (5) include the calculation of an elastic potential V according to the following equation:
    1 2 V = - kwh (Y-Yo)
    where ^ is the wrapping angle, ^ or is the resting angle and L is the resting length of the basting contact (5).
    [4]
    4. Method implemented by computer according to any of the
    preceding claims, wherein the structural information retrieved from the woven textile includes the modulus (B) of bending of the threads, and wherein the force model includes bending forces using the calculation of an elastic potential V between two consecutive yarn segments [ q2, q0] and [q0, q1] according to the following equation:
    V = k
    b
    Au
    where kb = BnR2, where R is the radius of the thread, Au is the sum of the arc length of both segments, and 0 is the angle of flexion between the thread segments [q2,
    5
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    30
    qo] and [qo, qi].
    [5]
    5. Method implemented by computer according to any of the
    preceding claims, wherein the structural information retrieved from the woven textile includes the coefficient (p) of friction by sliding of the threads, and wherein the force model includes friction forces by sliding using the coefficient (p) of friction by sliding and the coordinates (u, v) of sliding.
    [6]
    6. Method implemented by computer according to any of the
    preceding claims, wherein the structural information retrieved from the woven textile includes the elastic modulus (Y) of the threads, and wherein the force model includes stretching forces.
    [7]
    7. System to simulate the behavior of a woven textile at the thread level, the system comprising:
    - data storage means for storing structural information of a woven textile, at least said structural information comprising the disposition of the woven textile including the density of basting in the directions of row and columns and the type of each basting; Y
    - means for data processing configured for:
    retrieve said structural information and apply boundary conditions in a plurality of time stages;
    represent each basting of tissue or reverse point using four contact nodes (4), located at the end of the two basting contacts (5) between pairs of loops (2), where each contact nodule (4) is described by a coordinate (x) of 3D position representing the position of the contact node (4) and two sliding coordinates (u, v) representing the arc lengths of the two wires in contact;
    measure forces in each contact node (4) based on a force model, the forces being measured both in the 3D position coordinate (x) and the sliding coordinates (u, v) of the contact node (4), and including at least the force model wrapping forces to capture the interaction of the threads in the basting;
    calculate the movement of each contact nodule (4) in a plurality of time stages using motion equations derived using the Lagrange-Euler equations, and numerically integrated with time, where the motion equations take into account the density of mass distributed evenly along the threads, as well as the measured forces and boundary conditions.
    [8]
    8. Computer program product for simulating the behavior of a woven textile at the thread level, characterized in that it comprises a program code usable by a computer to carry out the steps of the computer implemented method defined in any of claims 1 to 6.
    10 9. Computer program product according to claim 8,
    characterized in that it is stored in a medium for program support.
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    同族专利:
    公开号 | 公开日
    CN108140015A|2018-06-08|
    AU2016293202B2|2018-03-29|
    MX2018000501A|2018-05-11|
    ES2597173B2|2017-10-16|
    EP3324300A4|2019-04-03|
    EP3324300A1|2018-05-23|
    KR20180027587A|2018-03-14|
    US10810333B2|2020-10-20|
    AU2016293202A1|2018-02-01|
    CA2992394A1|2017-01-19|
    IL256878D0|2018-03-29|
    JP2018524724A|2018-08-30|
    SG11201800280SA|2018-02-27|
    US20200410146A1|2020-12-31|
    KR101887467B1|2018-09-10|
    US20180203958A1|2018-07-19|
    HK1256331A1|2019-09-20|
    WO2017009514A1|2017-01-19|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP1439476A2|2003-01-10|2004-07-21|Choi, Kwang-Jin|Computer Graphics Techniques for Modeling Cloth|
    US20100306082A1|2009-05-26|2010-12-02|Wolper Andre E|Garment fit portrayal system and method|
    JP2013002013A|2011-06-15|2013-01-07|Mitsuboshi Belting Ltd|Method of forming textile material model, device for forming textile material model, method of forming interface model between textile material and adhesive liquid, device for forming interface model between textile material and adhesive liquid, method of predicting exfoliation property of interface between textile material and adhesive liquid, and device for predicting exfoliation property of interface between textile material and adhesive liquid|
    CN102750405B|2012-06-05|2014-11-12|浙江理工大学|Computer simulation method of spun-dyed fancy fabrics|
    US20030170420A1|2001-07-20|2003-09-11|Higgins Kenneth B.|Residential carpet product and method|
    JP4237601B2|2003-10-15|2009-03-11|株式会社島精機製作所|Loop simulation apparatus and method and program thereof|
    GB2420643B|2004-11-30|2011-01-12|Innoval Technology Ltd|Fabric modelling|
    KR100914869B1|2007-05-29|2009-08-31|에프엑스기어|System and Method for Real-Time Cloth Simulation|
    CN101944144B|2010-08-30|2012-08-01|陈玉君|Meshless cloth-based simulation method|
    CN104679958B|2015-03-12|2018-02-06|北京师范大学|The method of ball B-spline tricot deformation emulating based on spring model|CN109583048A|2018-11-14|2019-04-05|江南大学|A kind of three dimensional needle cloth modeling method based on hexagonal mesh structure|
    CN113551634B|2021-09-18|2021-11-23|南通素芮纺织科技有限公司|Flat knitting machine faller depth of parallelism detection device|
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    ES201531038A|ES2597173B2|2015-07-15|2015-07-15|Method implemented by computer, system and computer program product to simulate the behavior of woven textile at the thread level|ES201531038A| ES2597173B2|2015-07-15|2015-07-15|Method implemented by computer, system and computer program product to simulate the behavior of woven textile at the thread level|
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    US15/744,643| US10810333B2|2015-07-15|2016-07-15|Computer implemented method, system and computer program product for simulating the behavior of a knitted fabric at yarn level|
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