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This paper extends the linear complementarity problem formulation of [7] and [8] for normal impact of planar deformable bodies in multibody systems. In the kinematics of impact we consider the normal gaps between the impacting bodies in terms of the generalized coordinates. Then, the generalized coordinate’s vector is formulated in terms of the impact forces using the 5th order implicit Runge‐Kutta approach RADAU5. Substituting the generalized coordinates in the relation of normal gaps together with the complementarity relations of unilateral contact constraints leads to a linear complementarity problem where its solution results in the solution of the impact problem including impact forces and normal gaps. Then, alternatively another formulation on velocity level based on the 4th order explicit Runge‐Kutta is presented. In the presented approach no coefficient of restitution is used for treatment of energy loss during impact and, instead, the material damping is responsible for energy loss. A good agreement between the results of our approach with the results of FEM for soft planar deformable bodies was shown in [7]. Here, we improve the results for stiff planar deformable bodies and show that with a proper selection of eigenmodes, the results on both position and velocity level approach the precise results of FEM provided that an optimal time step of the integration is chosen. We also investigate the effect of considering material damping and some higher eigenfrequencies on the amount of energy which is dissipated during impact based on our approach.

A numerical technique is described for the analysis of multiple interacting deformable bodies undergoing large displacements and rotations. Each body is considered an individual discrete unit, which is idealized by a finite element model. Discrete finite element models interact with their surroundings through contact stresses, which are continually updated as the elements move and deform. The method of analysis consists of a finite element formulation based on a generalized explicit updated Lagrangian method. This formulation is a general finite element formulation, that permits the large deformation analysis of both continuum and discontinuum systems. Different validations of the proposed method of analysis, including cases that involve very large rotations, as well as some examples that demonstrate the application of the discrete finite element method to problems in rock mechanics are presented and discussed in the paper.

The body model which has been utilized in our clothing simulation does not deform and gives a boundary condition for mechanical calculation. To determine the shape of clothing in the case where clothing and body mechanically interact with each other, the body model used for this purpose has to be deformable. In this study, basic techniques for realization of the deformable body model were investigated. A tetrahedron was defined as a fundamental element for mechanical calculation of solid, and it was formulated with ordinal strain. Four kinds of cubes consisting of six tetrahedrons were defined as basic geometrical elements for constructing solids. Two kinds of cantilevers were constructed from the cubes and mechanical simulation was carried out with proper mechanical properties. A method of estimating internal mechanical properties of the human body was tested. The method is a modification of the simulation and is one of inverse problems. Treatment of collision is required for the simulation in which clothing and body mechanically interact with each other. The treatment of collision is based on a triangular element, and the processes consist of its detection and resolution. Simulation of a right cylinder solid wound by fabric like pipe was carried out to check collision treatment.

The purpose of this paper is to explore the simulation of garments with various combinations of shape and size using a parametric pattern design method.

The approach of this study is to design garment patterns using a text‐based script language and assemble them on a deformable virtual body model to evaluate the appearance and fit of the resulting garment to facilitate the garment design process.

In this study, various garment patterns are designed parametrically by an expandable script language and simulated directly on a deformable body model.

The size and shape of parametrically generated garment patterns are all different for each garment and therefore a full‐texture mapping technique cannot be applied.

This method may reduce the time required to evaluate the appearance and fit of bespoke garments by replacing the trial‐and‐error based traditional procedures.

The integration of a script‐based parametric pattern design method into the garment drape simulation system is one of the most useful applications for the practical garment design process.

The generation of individually fit basic garment pattern is one of the most important steps in the garment‐manufacturing process. This paper seeks to present a new methodology to generate basic patterns of various sizes and styles using three‐dimensional geometric modeling method.

The geometry of a garment is divided into fit zone and fashion zone. The geometry of fit zone is prepared from 3D body scan data and can be resized parametrically. The fashion zone is modeled using various parameters characterizing the aesthetic appearance of garments. Finally, the 3D garment model is projected into corresponding flat panels considering the physical properties of the base material as well as the producibility of the garment.

The main findings were geometric modeling and flat pattern generation method for various garments.

Parametrically deformable garment models enable the design of garments with various size and silhouette so that designers can obtain flat patterns of complex garments before actually making them. Also the number and direction of darts can be determined automatically considering the physical property of fabric.

The purpose of this paper is to propose a computational approach in order to help establish the effect of various self-piercing rivet (SPR) process and material parameters on the quality and the mechanical performance of the resulting SPR joints.

Toward that end, a sequence of three distinct computational analyses is developed. These analyses include: (a) finite-element modeling and simulations of the SPR process; (b) determination of the mechanical properties of the resulting SPR joints through the use of three-dimensional, continuum finite-element-based numerical simulations of various mechanical tests performed on the SPR joints; and (c) determination, parameterization and validation of the constitutive relations for the simplified SPR connectors, using the results obtained in (b) and the available experimental results. The availability of such connectors is mandatory in large-scale computational analyses of whole-vehicle crash or even in simulations of vehicle component manufacturing, e.g. car-body electro-coat paint-baking process. In such simulations, explicit three-dimensional representation of all SPR joints is associated with a prohibitive computational cost.

It is found that the approach developed in the present work can be used, within an engineering optimization procedure, to adjust the SPR process and material parameters (design variables) in order to obtain a desired combination of the SPR-joint mechanical properties (objective function).

To the authors’ knowledge, the present work is the first public-domain report of the comprehensive modeling and simulations including: self-piercing process; virtual mechanical testing of the SPR joints; and derivation of the constitutive relations for the SPR connector elements.

The purpose of this paper is to analyze automation of body surface shape.

Numerous body landmarks are detected automatically. Body surface can be subdivided into multiple patches in a consistent manner using parametric design method.

Complex surface shape of various human bodies can be analyzed easily and consistently.

The proposed method may not be applicable for a body with the shape which significantly differs from that of an average body.

This method can greatly reduce the time required to analyze the surface shape of a three dimensional body scan data.

The analysis of body surface shape is one of the most important processes especially in designing close fitting garments. The parametric design of body surface patches will facilitate the analysis of numerous body scan data.

A consistent formulation for unilateral contact problems including frictional work hardening or softening is proposed. The approach is based on an augmented Lagrangian approach coupled to an implicit quasi‐static Finite Element Method. Analogous to classical work hardening theory in elasto‐plasticity, the frictional work is chosen as the internal variable for formulating the evolution of the friction convex. In order to facilitate the implementation of a wide range of phenomenological models, the friction coefficient is defined in a parametrised form in terms of Bernstein polynomials. Numerical simulation of a 3D deep‐drawing operation demonstrates the performance of the methods for predicting frictional contact phenomena in the case of large sliding paths including high curvatures.

The numerical simulation of metal forming processes approximated by means of finite element techniques, require large computational effort, which contradicts the need of interactivity for industrial applications. This work analyses the computational efficiency of algorithms combining elastoplasticity with finite deformation and contact mechanics, and in particular, the optimum solution of the linear systems to be solved through the incremental‐iterative schemes associated with non linear implicit analysis. A method based on domain decomposition techniques especially adapted to contact problems is presented, as well as the improved performance obtained in the application to hot rolling simulation, as a consequence of bandwidth reduction and the differentiated treatment of subdomains along the non linear analysis.

The purpose of this paper is to facilitate the digital garment production process using a multi‐option garment data structure.

Numerous garments can be generated out of a single garment datum by combining various fashion features, size grades, fabric physical properties, and surface texture maps.

It is found that various digital garments which are required, for example, by online fashion businesses can be prepared in a relatively simple way.

The size of each pattern on a garment can be changed by grading process and therefore a full‐texture mapping technique cannot be applied.

This method can greatly reduce the time required to prepare the digital garments, for either online or offline fashion businesses.

The generation of various digital garments by combining multiple fashion features and physical properties is one of the most important features needed for the practical application of drape simulation in the fashion business.