上海大学-法国技术大学集团联合学术报告系列——应用于金属变形的先进网格重划过程

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UTSEUS点击上方“UTSEUS”可订阅哦！【上海大学-法国技术大学集团
联合学术报告系列】


【报告时间】
2016年3月3日 上午9:00-10:00 【报告地点】上海大学延长校区 材料科学与工程学院 金属楼 二楼会议室 【所属院校】法国特鲁瓦技术大学
(Université de Technologie de Troyes)
【主办单位】材料科学与工程学院中欧工程技术学院 【报告题目】应用于金属变形的先进网格重划过程
（Advanced remeshing procedure
applied to metal forming）
【报告人】CHEROUAT Abel 【摘要】当金属材料由巨大的非弹性变形而造成形变时，韧性微缺陷(空隙)核化，生成高应力的局部区域。在一些金属薄板成型过程（如深拉）中应避免这种危害的发生，以求获得初始无损的成型件。与此相对，在板材切割过程中（如冲割、纵切、剪切、冲压），韧性损伤被设计为一种可沿集中剪切变形区域产生可控显微裂纹的操作。因为施加了大热塑性应变及损伤，表征工件的有限元网格发生剧烈的畸变，因此有必要为计算域的变形（演进）几何呈现重划网格或生成新的网格。由此可见。必须更新网格，使之与变形后的几何结构相一致，在关键区域格点应足够致密，而其他部位可保持适当稀疏。在计算域的变形过程中通过采用适合的自适应网格生成器，以形状优化的元素对新的几何结构进行网格重划，求解的变量映射在新的网格之上，在此基础上作进一步的分析。


When a metallic material is formed by very large inelastic deformations, ductile micro-defects (voids) nucleate and grow inside a high strain localization zones. This damage occurrence is generally avoided in some sheet metal forming processes, as deep-drawing, in order to obtain a virgin undamaged formed piece. On the contrary, for sheet cutting processes as blanking, slitting, shearing or punching, the ductile damage is designed into an operation by generating controlled macroscopic cracks through the intensively shear deformed zones.
Also, due to the imposition of large thermo-plastic strains, damage, the finite element mesh representing the workpiece undergoes severe distortion and hence, necessitates remeshing or the generation of a new mesh for the deformed/evolved geometric representation of the computational domain. It is therefore necessary to update the mesh in such a way that it conforms to the new deformed geometry and becomes dense enough in the critical region while remaining reasonably coarse in the rest of the domain.
During the deformation of the computational domain, the new geometry is remeshed with optimally shaped elements using a suitable adaptive mesh generator, and the solution variables are projected on the new mesh, and the analysis is continued.
【关键词】有限元方法、自适应网格重划分、金属成形、有限应变、计算损伤力学Finite Element method, Adaptive Remeshing, Metal Forming, Finite Strain, computational damage mechanic 【教职】全职教授（Since 2002 : Full Professor） 【研究领域】CAD设计、先进3D重构、生物机械、Ansys网格、创新材料与成型过程、先进有限元模拟、可靠性优化Design CAD, Advanced 3D reconstitution, Bio-mechanic, Meshing-remeshing, Innovative materials and forming processes, Advanced Finite Element Simulation, Reliability-Optimization