梁的蠕变开裂各向同性弯曲损伤分析

AN ISOTROPIC DAMAGE ANALYSIS ON BEAMS UNDER CREEP PURE BENDING LOAD

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）定义拉伸损伤变虽类似，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，所得计算结果与Ｋａｃｈａｎｏｖ拉伸损伤模型所得结果比较吻合，表明该弯曲损伤模型是合理适用的。

In this paper, based on the assumptions of pure bending damage of beams, the elementary equations on bending damage are developed. Similar to the tensile damage variable defined as reduction of loading area by L.M. Kachanov,the bending damage variable is defined as reduction of moment of inertia. For the simplicity of application in engineering,asimple bending damage model is proposed.At last,an exact creep pure bending damage analysis is made, based on which the materials’constants of the simple bending damage model are obtained in first approximation. Its calculating results are in good agreement with the results of exact solution.