基于高阶复合曲面单元的非均匀大薄板装配偏差计算模型  

Model of Assembly Deviation of Irregular Large Thin-Walled Structures Based on Higher-Order Composite Shell Element

作　　者：林张鹏 余海东[1] 袁可 LIN Zhangpeng;YU Haidong;YUAN Ke(Shanghai Key Laboratory of Digital Manufacture for Thin-Walled Structures,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学上海市复杂薄板结构数字化制造重点实验室,上海200240

出　　处：《上海交通大学学报》2022年第5期584-593,共10页Journal of Shanghai Jiaotong University

基　　金：国家重点研发计划(2019YF0709000);国家自然科学基金(51775345)资助项目。

摘　　要：结构的刚度非均匀分布易导致非规则大型薄壁在加工和装配过程中产生翘曲大变形,其结构建模和变形精确计算是装配偏差预测及控制的关键.基于绝对节点坐标法,引入高阶斜率坐标并改进单元插值函数,考虑单元接触界面间连续性,构建一种非规则高阶曲面复合单元模型;采用该非规则高阶曲面单元建立复合单元组合离散非规则曲面结构,解决不同厚度单元间节点连接和变形耦合问题,并有效地描述非规则大型薄壁结构的大变形,基于连续介质力学建立非规则大型薄壁结构装配协调变形计算模型.对重型火箭贮箱箱底边缘区域加厚的超大型非规则薄壁结构进行装配过程变形计算,研究加厚区域尺寸与瓜瓣装配偏差以及结构刚度之间的关联关系,为未来重型火箭箱底超大非规则曲面结构设计提供指导.The non-uniform stiffness distribution of irregular large thin-walled structures leads to warping deformation in the process of machining and assembly. The structure modeling and accurate calculation of the large deformation is the key to predict and control the deviation. A novel irregular higher-order composite shell element based on the absolute nodal coordinate formulation(ANCF) was proposed to accurately calculate the deformation of irregular large thin-walled structures with higher-order slope coordinates and improved shape function, considering the continuity of elements at the contact interface. A discrete method of irregular large thin-walled structures was proposed to solve the problem of node connection and deformation coupling between elements with different thicknesses, and to describe the large deformation of irregular large thin-walled structures effectively by using the combination of irregular higher-order elements and composite elements. An assembly deformation calculation model of irregular large thin-walled structures was proposed based on continuum mechanics. The influence of the thickened area on assembly deviation and stiffness of scalloped segment structures of heavy rocket tank bottom was studied with the new elements and calculation model, so as to provide guidance for structure design.

关 键 词：非规则薄壁结构 绝对节点坐标法 复合单元 装配偏差 协调变形 

分 类 号：TH113[机械工程—机械设计及理论]