基于金属密封垫圈非线性变形仿真的预紧设计

为确保密封结构能有效阻止箱体内部介质的泄漏,要求密封面具备一定的密封比压,即通过施加合理的拧紧力矩来控制密封件的压缩量。目前主要采用试验方法验证一系列拧紧力矩下的密封效果,从而获取临界力矩值并确定可靠的拧紧力矩设计值。文章基于试验经验做出了合理的假设以建立简化的非线性有限元分析模型,对金属垫圈在压紧力下的塑性变形进行仿真,通过金属垫圈发生临界变形量的压紧力反推出拧紧力矩的临界值。该方法获取的临界力矩值与试验方法相近,可以有效地提高设计效率,降低试验成本。

Design of tightening torque based on nonlinear deformation simulation of metallic seal ring

In order to assure that the sealing structure can effectively prevent the leakage of the medium inside a tank, it is important that the sealing surface is under certain fasten pressure. Therefore, a proper tightening torque should be applied for the compression of the seal ring, to guarantee the sealing of the structure. At present, the critical value of the tightening torque is mainly obtained by carrying out a series of experiments with different torque values and testing the sealing effect, and a reliable design value of the tightening torque is then obtained subsequently. Based on the experience learned from those experiments, a reasonable hypothesis is made to establish a simplified nonlinear finite element model, which simulates the plastic deformation of the seal ring under a given pressure. The critical tightening torque value is then determined from the critical pressure, with the desired deformation to the seal ring. The design value from this simulation is in agreement with that from the experiments, and, therefore, this method can be used to improve the efficiency of the design and to reduce time and experimental costs.