用无拉应力计算模型分析道床变形

Analyses of Ballast Deformation by Non-tension Stress Model

道床是一种散体材料，不能承受拉应力。现行的有限元分析方法，得到道床内出现拉应力的分析结果，这与实际情况是相违背的。本文采用修正拉应力，进而修正荷载向量的方法，论述了无拉应力计算模型的原理。运用无拉应力计算模型，考虑道碴的非线性性质，对铁路道床进行了力学分析。计算结果表明，本文的算法切实可行，道床内应力分布的精度较高。本算法还可以推广应用于其它各种不能承受拉应力的材料力学分析问题。

Ballast is a body of loose material, which suffers no tension stress. With the standard finite element analysis tension stress appears in the ballast bed in violation of the condition real. In the paper, by way of correcting the tension stress and the load vector, the principle of a non-tension stress computation model is developed. Using this model and considering the nonlinear property of the ballast, analyses of ballast deformation are udertaken. Calculation shows that the algorithm presented in the paper is both highly accurate and easy to perform. It can also be applied to other material which does not allow tension stress.