Dhital Sukirti, Rokaya Asmita, Kaizer Marina R, Zhang Yu, Kim Jeongho
Department of Civil and Environmental Engineering, University of Connecticut, 261 Glenbrook Rd., U-3037, Storrs, CT 06269.
Department of Biomaterials and Biomimetics, New York University College of Dentistry, 433 First Avenue, New York, NY 10010.
Compos Struct. 2019 Aug 15;222. doi: 10.1016/j.compstruct.2019.110909. Epub 2019 Apr 25.
Functionally graded materials have found a wide usage in high temperature applications. The smooth transition from one material to another, in graded materials, may reduce thermal stresses, residual stresses and stress concentration factors as well as utilize properties of both materials. To perform accurate and efficient finite element analysis for heat transfer and transient thermal stress analyses in two-dimensional functionally graded materials, incompatible graded finite elements are developed and verified. User-defined subroutines in ABAQUS are developed to address the gradation of material properties within an element. An emphasis is made on an incompatible graded finite element (QM6) which is accurate and efficient compared to linear four-node (Q4) and quadratic eight-node (Q8) elements. With the help of posteriori error estimation, a critical comparison is made among three types of solid elements. Modified 6-node (QM6) incompatible graded elements provide better accuracy than Q4 elements and take less computational time than Q8 elements, thereby showing QM6 as an optimal element for engineering analysis.
功能梯度材料在高温应用中得到了广泛应用。在梯度材料中，从一种材料到另一种材料的平滑过渡可以降低热应力、残余应力和应力集中系数，同时利用两种材料的性能。为了对二维功能梯度材料中的传热和瞬态热应力分析进行准确高效的有限元分析，开发并验证了不相容梯度有限元。在ABAQUS中开发了用户定义子例程，以处理单元内材料属性的渐变。重点介绍了一种不相容梯度有限元（QM6），与线性四节点（Q4）和二次八节点（Q8）单元相比，它既准确又高效。借助后验误差估计，对三种类型的实体单元进行了关键比较。改进的6节点（QM6）不相容梯度单元比Q4单元具有更高的精度，比Q8单元占用更少的计算时间，从而表明QM6是工程分析的最佳单元。
