柴油机机体高强度螺栓预紧力的有限元计算方法

针对传统的螺栓预紧力计算方法误差较大的问题,采用有限元法进行刚度计算。建立了相关零部件三维实体模型,根据螺纹部分受力分布情况,选取适当位置和载荷,运用有限元法计算连接件与被连接件变形量,根据载荷和变形量计算刚度,根据刚度和相关参数计算螺栓预紧力。采用应变计法测量了螺栓预紧力,并与计算结果进行了对比,结果表明,有限元方法计算结果与实测值的相对误差仅为1.76%。

FEA Calculation Method of Pre-tightening Force for High Strength Bolt Used in Diesel Engine Block

For the existing large error of calculating bolt pre-tightening force with the traditional method,the stiffness calculation of bolt was carried out with the FEA method.The 3D solid model of related parts was built,the load and distribution were selected according to the distribution of screw thread bearing force,the strain between connecting fitting and connected fitting was calculated with the FEA method,the stiffness was calculated according to the load and strain,and the pre-tightening force was calculated according to the stiffness and related parameters.The pre-tightening force of bolt was measured with the strain gauge method and was compared with the FEA results.The results show that the relative error between FEA results and measured results is only 1.76%.