考虑结构非线性特征的参数化形状优化方法

提出并实现一种将参数化设计技术应用于考虑结构非线性特征的形状优化设计领域的新方法。参数化设计技术是近年来发展起来的新一代CAD软件平台的核心技术之一。文中基于三维参数化CAD平台 ,将参数化设计技术、有限元建模技术与有限元分析优化系统集成为参数化的形状优化系统 ;引入非线性分析技术 ,以解决工程上大量存在的非线性形状优化问题。该方法克服了以往形状优化方法应用于三维实体结构时所面临的几何形状描述、约束与驱动的困难 。

液压支架顶梁的弹塑性分析

在液压支架的设计中,传统的方法是把顶梁假设成杆,用材料力学的方法计算其危险截面的应力,并且把弹性极限弯矩作为设计时的最大许用弯矩。本文把顶梁假设成—交叉梁系,对其作了弹塑性有限元分析,导出了部分节点弯矩超过弹性极限弯矩的梁单元刚度矩阵,并对计算方法的收敛性作了讨论,分析了液压支架在部分节点达到塑性后的安定问题。

Influence of Residual Stress on the Elastic-plastic Response to Indentation

The indentation method is useful in determining the residual stress according to the elastic-plastic properties of materials.So the effect of the residual stress on the elastic-plastic indentation properties of materials was studied by using the finite element method to find better indentation parameters which are strongly induced by the residual stress.The results show that load-depth curve,plastic pile-up,indentation shape,indentation contact stress and indentation residual stress are affected by different residual stress,and these parameters can be used to deduce the residual stress.Also,a special indentation equipment was developed to analyze the elastic-plastic properties of materials with different residual stress,and the experimental results show a good agreement with the FEM results.For practical application,the elastic-plastic indentation properties of materials with unknown residual stress could be obtained by the developed equipment to deduce the residual stress comprehensively.

弹塑性结构的动力学塑性变形的上界

本文借助于虚载荷方法讨论了弹性完全塑性结构在动载荷下塑性变形的上界问题,结出了塑性变形的上界估计式.同时,在假设分段线性加载面的情况下,将结果推广到线性强化结构.此外,本文还给出一例,将所得结果与精确解进行了比较,表明本文的结果有较大的实用价值.

江山虎山运动公园体育馆动力弹塑性分析

浙江省衢州市江山虎山体育馆为框架-剪力墙结构,建筑平面为矩形,结构长107.9 m,宽98.8 m,体育馆屋盖采用张弦梁结构体系,檐口高度23.25 m,屋面最高点25.50 m,最大跨度约66 m。论文通过SAP2000及Midas软件对江山虎山运动公园体育馆进行模态分析及弹塑性时程分析。分析结果表明:大震作用下结构能满足规范限值要求;结构耗能主要集中于阻尼耗能和塑性耗能;梁端先于墙柱形成塑性铰,能够满足“强柱弱梁”的要求。