高强度螺栓塑性变形仿真分析与拧紧试验研究

Simulation Analysis of Plastic Deformation Characteristics of High Strength Bolts and its Fastening Experimental Research

为了确保大批量生产装配模式下高强度螺栓的拧紧质量和可靠性,对高强度螺栓伸长量进行抽检测量,验证和检验螺栓拧紧参数设置的合理性。以某发动机主轴承盖螺栓为研究对象,结合实例对高强度螺栓在拧紧过程中变形可能超过弹性变形范围而引发较大的非线性塑性变形,使螺栓强度下降从而导致螺栓失效的情况进行分析,基于扭矩-转角法,采用有限元法-双线性模型和试验法对螺栓的伸长量进行仿真分析和试验验证。结果表明:采用40 N·m扭矩+90°转角进行拧紧时,螺栓的平均伸长量逼近最大允许值,不适用于大批量螺栓拧紧;采用40 N·m扭矩+80°转角进行拧紧时,螺栓平均伸长量为满足设计要求。仿真结果与试验平均值较为接近,仿真方法可靠。

In order to ensure the tightening quality and reliability of high-strength bolts in mass production and assembly mode, the elongation of high-strength bolts was measured to verify and the rationality of bolt tightening parameters. Taking the bolt of the main bearing cover of an engine as the research object, the non-linear plastic deformation caused by the deformation of the high strength bolt which may exceed the elastic deformation range during the tightening process, and the failure of the bolt caused by the large plastic deformation will decrease the strength of the bolt is researched. Based on the torque-angle method, finite element-bilinear model and experimental method are used to simulate and verify the elongation of the bolt. The results show that the average elongation of bolts approximates the maximum allowable value when the torque is 40 N·m + 90°, which is not suitable for large-scale bolt tightening. When the torque is 40 N·m + 80°, the average elongation of bolts meets the design requirements. The simulation results are close to the experimental average, and the simulation method is reasonable and credible.