球面接触面积对扣件T形螺栓应力的影响

Influence of Sphere Contact Area on Stress of T-shape Bolt in Fastener

利用有限元方法建立数值计算模型,模拟北京地铁14号线扣件系统T形螺栓的实际工作状态,并通过改变螺栓轴向约束面积模拟球面的实际接触面积,分析T形螺栓在不同边界条件下螺栓根部的最大等效应力分布,对比T形螺栓屈服极限应力,分析不同约束面积对T形螺栓强度的影响。根据数值计算结果得出结论:随着轴向约束面积的减小,T形螺栓根部最大等效应力逐渐增大,当轴向约束面积小于球面1/3时,螺栓根部最大等效应力超过螺栓强度极限,此时螺栓发生屈服破坏。

The numerical calculation model was established by using the finite element method to simulate the T-shape bolt actual working state of fastening system in Beijing metro line No.14,the maximum equivalent stress distribution of T-shape bolt root under different boundary conditions was studied through simulating the actual sphere contact area which was changed with bolt axial restraint area,and influence of different restraint area on the strength of T-shape bolt was analyzed by comparing the yield ultimate stress of T-shape bolt.The numerical calculation results showthat the maximum equivalent stress of T-shape bolt root increases gradually with the decrease of the axial restraint area,the maximum equivalent stress of T-shape bolt root is beyond the bolt strength limit when the axial restraint area is less than one third of the sphere area and the yield failure of bolt happens at the same time.