弹塑性梯度材料热机耦合分析的有限元方法  

Graded Finite Element Method for Mechanistic Analysis of Heterogeneous Structure

作　　者：田珂[1] 张光[1] 陶亮[1] 

机构地区：[1]西北工业大学航空学院,西安710072

出　　处：《航空工程进展》2014年第1期59-63,共5页Advances in Aeronautical Science and Engineering

基　　金：国家自然科学基金(50371070)

摘　　要：陶瓷/金属功能梯度材料(FGMs)的组份及性能梯度分布,在航空航天高温热结构中有重要应用。材料性能在空间上的连续变化给这类结构强度设计的有限元分析造成了一定困难,针对上述问题,提出一种热弹塑性梯度有限元方法。该方法通过编写有限元软件ABAQUS的材料用户子程序(UMAT)来实现,在UMAT中将FGMs的弹塑性本构模型参数定义为空间坐标的函数;用热弹塑性梯度有限元方法对陶瓷-FGMs-金属典型的三明治板结构进行热机械分析。结果表明:FGMs组分布函数对其热应力分布有很大的影响,特别是在三明治结构的界面上,影响更为突出,这和现有文献的实验结果相符。Ceramic/metal functionally graded materials（FGMs）, with its components and its performance gradi- ent distribution are of important applications in the aerospace high temperature thermal structure. There are certain difficulties in the finite element analysis directly for such structural strength design, because of the con- tinuous changes in the material properties of the FGMs in the space. By taking into account of thermal and plas- tic behaviors of materials, a thermo-elasto-plastic graded finite element method has been derived. The method, being capable of describing spatially varying material properties, has been implemented in the commercial finite element code ABAQUS by using user-defined material subroutines for solving engineering problems. To illus- trate the applicability of the method, a case example has been preformed to study the mechanical response of a ceramic-FGMs-metal sandwich structure. The calculation results show that Distribution functions of its compo- nent are of great influence on the distribution of thermal stress, particularly in the interface of the sandwich structure, which is consistent with the experimental results of the existing literature.

关 键 词：弹塑性 功能梯度材料 梯度有限元 热应力 

分 类 号：O346[理学—固体力学] V232.4[理学—力学]