梁的蠕变脆性各向同性弯曲损伤模型

A Creep Bending Damage Model on Beams

本文在梁的纯弯曲损伤基本假设条件下，导出了弯曲损伤的基本方程，与Ｋａｃｈａｎｏｖ的材料刚度劣化（受载横截面积减小）定义拉伸损伤变量类似，以梁的弯曲刚度劣化（惯性矩减小）定义弯曲损伤变量，从而建立了与Ｋａｃｈａｎｏｖ拉伸损伤模型相类似的梁的各向同性弯曲损伤模型。最后，以受蠕变纯弯曲梁为实例进行了损伤分析，在一次近似条件下，该弯曲损伤模型的材料常数可由Ｋａｃｈａｎｏｖ拉伸损伤模型的材料常数确定，且所得计算结果与Ｋａｃｈａｎｏｖ拉伸损伤模型所得结果比较吻和，表明该弯曲损伤模型是合理适用的。

In this paper,based on the basic assumptions of pure bending damage of beams,the elementary equations are drived, in which the definition of bending damage variable is defined by reduction of moment of inertia similar to that of tensile damage variable defined by reduction of loading area,a simple bending damage model is proposed similar to kachanov's tensile damage model.As an example,a bending damage analysis of a beam for creep pure bending is made,the material's constants of the simple bending damage model can be determined in first approximation to kachanov's tensile damage model,the calculating results are compared in good agreement with the results obtained by kachanov's tensile damage model.It shows that the bending damage model is reasonable.