小湾水电站事故链轮门轮轨接触分析

采用有限元混合法对5 000 kN级的小湾水电站事故链轮门轮轨接触问题进行了分析。首先给出三维有初始间隙摩擦接触问题的力学模型,推导出相应的有限元方程,然后给出迭代求解步骤。计算结果表明,虽然表面接触点的最大压应力大大超出容许压应力,但由于接触区域附近处于三向受压状态,最大剪应力发生在表面接触点以下3.4 mm,不会引起表面的屈服破坏,辊轮的承载能力可以进一步提高,有一定的强度富裕空间。

Analysis of Wheel-rail Contact Problem for Wheel Track Gate at Xiaowan Hydropower Plant

Using the Mixed Finite Element Method,the analysis of 5000KN wheel-rail contact problem for wheel track gate of Xiaowan hydropower plant is carried out.Based on the characteristicof local nonlinearityfor this problem,the system of forcesacting on the contactor in this method was divided into two parts: external forces and contact forces.The displacement of contactor was chosen as the basic variable and the nodal contact force in possible contact region was chosen as the iterative variable,so that the nonlineariteration process was only limited in the possible contact surface.Thus the iterative procedure can be easily carried out and much more economical.Firstly,the mechanical model for three-dimensional dynamic contact problemswith friction and initial gaps was presented,and its finite element equations were obtained.And then,the iteration processwas given in detail.It shows that,although the maximum compression stressis much more than the permissible stress,the surficial yield failurewill not be taken place because the region around the contact point is applied by triaxial compression,and the point of maximum shear stressis below the contact point 3.4mm.So we can concludethat the carrying capacityof the wheel can be enhanced.