焊接残余应力强度因子的权函数法求解
收稿日期: 2014-10-31
修回日期: 2014-12-15
网络出版日期: 2014-12-19
基金资助
国家自然科学基金(11402249)
Determination of welding residual stress intensity factors by weight function methods
Received date: 2014-10-31
Revised date: 2014-12-15
Online published: 2014-12-19
Supported by
National Natural Science Foundation of China (11402249)
复杂焊接残余应力场作用下的应力强度因子是焊接结构损伤容限分析的前提。权函数法是求解任意载荷下应力强度因子的高效手段,但裂纹几何的复杂性给经典权函数法的应用带来了障碍。本文利用一种新的基于复变函数泰勒级数展开的权函数解法,通过复变有限元计算,求解裂纹面位移对裂纹长度的偏导数,采用经典权函数的级数展开式作拟合,确定无限大板周期性共线裂纹、有限宽板中心裂纹以及有限宽板单边裂纹的权函数,并确定了这3类裂纹在典型焊接残余应力作用下的应力强度因子。与经典权函数法、有限元法以及有关文献结果的广泛对比表明,基于复变函数泰勒级数展开的权函数法,为包括焊接残余应力的复杂载荷条件下的裂纹问题求解提供了高效高精度的手段。
景致 , 吴学仁 , 童第华 , 陈勃 . 焊接残余应力强度因子的权函数法求解[J]. 航空学报, 2015 , 36(11) : 3586 -3594 . DOI: 10.7527/S1000-6893.2014.0339
Stress intensity factor due to complex welding residual stress is a prerequisite for damage tolerance analysis of welded structures. The weight function method is a powerful tool for calculating stress intensity factors under arbitrary loads. However, application of the classical weight function method has been hampered by the crack geometry complexity. In this paper, using a new weight function approach based on complex Taylor series expansion, the first partial derivative of crack opening displacement with respect to crack length is determined from complex finite element computation. Classical series expansion expressions are used to curve-fit the weight functions for three crack geometries:a periodic array of collinear cracks in an infinite sheet, a center crack in a finite width sheet and an edge crack in a finite width sheet. The stress intensity factors for the three crack geometries subjected to typical weld residual stresses are determined. The results are widely compared with the classic weight function method, the finite element method and the well-known results in the literature. It is demonstrated that the weight function complex Taylor series expansion method is highly efficient and accurate for analyzing crack problems under complicate load conditions including weld residual stresses.
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