Non-linear Curve fitting to predict Von Misses Stress as a function of pore shape, size, location, and CTE parameters

The brazed joint assemblies are used for various critical applications including aerospace. So, the joint assembly should be optimized in terms of structure, materials, and porosity. A simulation study using Finite Element Method to optimize ceramic composite joint assembly is performed. The analysis concludes that pores do not always deteriorate joint performance. Variation of VMS with pore shape, size, location and CTE of material is estimated. An analytical non-linear equation to estimate the VMS value for any set of pore shape, size, location, and CTE parameter is proposed. The entropy is maximized and the coefficients of the parameters are estimated corresponding to maximum entropy. The fitted non-linear equations predicts the thermal stress of the joint assembly structure for a given material combinations and containing different shape and sized pores at different locations in the filler material of the assembly. 

钎焊接头组件可应用于包括航空航天在内的各类关键工程场景，因此需从结构设计、材料选型与孔隙率控制三个维度对其开展优化工作。本研究采用有限元法（Finite Element Method）针对陶瓷基复合材料接头组件开展优化仿真研究。分析结果表明，孔隙并非总会劣化接头的整体力学与服役性能。本研究探明了VMS随孔隙形状、尺寸、位置以及材料热膨胀系数（CTE）的变化规律，并提出了一种解析型非线性方程，可用于估算任意孔隙形状、尺寸、位置以及热膨胀系数参数组合下的VMS数值。研究以熵值最大化为优化目标，估算得到各参数的系数以匹配最大熵条件。该拟合得到的非线性方程可针对给定的材料组合，以及组件填充材料中不同位置、不同形状与尺寸的孔隙场景，精准预测接头组件结构的热应力。