运用ANSYS的复杂受力螺栓组联接失效分析

Static analysis of bolt group connection based on ANSYS

针对某自动扶梯驱动基座的T型螺栓组联接断裂失效问题,运用ANSYS workbench有限元分析软件建立其有限元模型。采用以螺栓中心点等效应力作为判定每条螺栓承担载荷的方法,结合事故过程和现场情况,对两种不同工况下的螺栓组联接进行静力学分析。结果表明,失效原因主要是螺栓防松脱措施不当,部分螺栓松脱后导致其他螺栓承担载荷严重不均,承担载荷较大的螺栓杆或螺栓头局部区域等效应力超出材料的屈服极限而断裂失效。断裂螺栓及断裂位置均与事故现场情况符合,验证了有限元分析的正确性,也以量化的方式论证了事故原因。

The finite element model based on ANSYS workbench is built to simulate the failure of bolt group connection in a bed of an escalator drive. According to the real accident, two different cases of the bolt group connection are analyzed. The equivalent stress on the center point far from constraints on the bolt was treated as a mark to identify the load borne by every bolt. It is shown that the inappropriate anti-loosening measures are responsible for the failure of the bolt group connection. When some of the bolts loosed, the load was shared unbalanced seriously between other bolts, in which the bolt or nut sharing more load must be frac-tured. The results are testified valid for their according with the scene of the accident and support the assumption of the failure causes by large amounts of data.