Dissertation > Industrial Technology > Metallurgy and Metal Craft > Metal pressure processing > General issues > Pressure processing

Meshless Method and Its Application in Metal Forming Process with Contact Interface of Arbitrary Shape

Author SuJianMin
Tutor WangYun;HuShuGen;SongXiaoWen
School Zhejiang University
Course Mechanical Design and Theory
Keywords The Galerkin no grid method Elastoplastic Contact interface of arbitrary shape Particle integration Projection subdomain
Type Master's thesis
Year 2010
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Metal plastic forming technology has an important position in the machinery manufacturing. Numerical simulation techniques to improve the level of controllability of the plastic forming process, is a powerful tool to optimize the process parameters and mold structure, important to ensure the quality of the workpiece, reduce material consumption and development time, reduce manufacturing costs. The finite element method is the most widely used and effective numerical simulation techniques. But so far, the finite element method simulation of metal forming process, there is the accuracy of the stress field to reach the engineering requirements and grid prone to distortion, many bottleneck problems. The root cause of these difficulties is that the the unit grid limitations of the finite element method. Grid method does not require a grid, to avoid the unit grid finite element method brought a series of difficult. It can not only guarantee the accuracy of the calculation, but also to reduce the difficulty of the calculation, therefore meshless method for the analysis of metal forming process has important theoretical and practical significance. Taking into account the contact interface of arbitrary shape is very common in metal forming contact situation, This article will not Metal Forming grid method for the analysis of the contact interface of arbitrary shape. The computational efficiency of the grid method is a key constraint, calculus and the contact interface processing algorithms are two important reasons to affect the efficiency of the grid method, so the papers from these two areas to start, focusing on research to improve grid method calculate the efficiency of the correlation algorithm. The paper is based on moving least square approximation Galerkin meshless method as a numerical analysis method using the elastic-plastic material model as the calculation of the material model. Contact interface in any shape processing, carried out a description of the mold cavity, contact search algorithm, France to the contact force and tangential to the friction calculation method. On this basis, the research-based the update Lagrangian description of the elastic-plastic material deformation process control solving equations and their corresponding matrix definition, and use the power of the central difference scheme based algorithm to solve this equation explicitly, eventually realized Galerkin meshless method in the numerical simulation of the contact interface of arbitrary shape metal forming process. The thesis innovative work the following two points: 1 particle integration method for the contact interface of arbitrary shape metal forming processes analysis, under the premise of guaranteeing the accuracy of a high-efficiency calculus. The particle integration method is a highly efficient and stable integration method, based on in-depth study of the contact interface of arbitrary shape processing algorithms, for the process of plastic deformation of a ball head shaped punch squeeze massive copper workpiece value Analysis. The calculation results are compared with the results obtained by the finite element method based on ANSYS / LS-DYNA environment, illustrates the correctness and feasibility of the scheme proposed in this paper. 2 surface methodology and integration algorithm based on the systematic study of the master from a new contact with a fast search algorithm projector subdomain method. The main contact of the surface of the mold cavity block and the surface of the workpiece from the contact point along the direction of movement of the press projection subdomain segmentation Thought split projection area of ??the contact interface with the rectangular sub-domains, from the point of contact and the main contact block fast matching determine the operation, so as to realize the test on and the determination of the contact pair. The example shows that the the subdomain projection method has faster processing speed, the implementation of convenient features.

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