基于钉杆变形均匀性的锥形半圆头铆钉优化设计研究

Research on the Optimum Design of Tapered Semi-Circular Head Rivet Based on the Uniformity of Rod Deformation

目的针对铆接过程中铆钉钉杆发生镦粗变形,其变形的均匀性影响连接接头力学性能的问题,提出一种钉杆带有锥度的变径铆钉,以改善钉杆变形的均匀性。方法基于三维有限元仿真方法,对准静态铆接过程进行仿真,获取锥形与常规半圆头铆钉在铆接后钉杆变形情况,同时对比分析板材残余应力变化情况。最后建立由钉杆变形均匀度与铆钉尺寸以及镦头高度组成的灰色系统,并通过对该系统进行关联度计算分析,确定铆钉尺寸及镦头高度对均匀度的影响。结果锥形铆钉铆接后钉杆均匀性优于常规铆钉。使用不同铆钉进行铆接,板材残余应力有着相同变化趋势。铆钉尺寸、镦头高度对钉杆变形均匀度的关联度计算结果分别为0.608和0.596,铆钉尺寸变化对均匀度的影响大于镦头高度变化。结论锥形铆钉对钉杆变形均匀性的改善有良好效果。

In order to solve the problem that the rivet rod had upsetting deformation in the process of riveting and the uni-formity of rod deformation affected the mechanical properties of the riveted joints,a type of variable diameter rivet with taper on rivet rod is proposed to improve the uniformity of deformation of the rivet rod.Based on three-dimensional finite element simulation,the quasi-static riveting processes were simulated,and the deformations of rivet rod of tapered rivet and conven-tional rivet were obtained.Furthermore,the changes of residual stress of plates were compared and analyzed.Finally,a gray system composed of deformation uniformity of rivet rod,rivet size and pier head height was established.Through correlation calculation and analysis of the system,the influences of rivet size and pier head height on uniformity were determined.After deformation,the tapered rivet has better uniformity of rivet rod than the conventional rivet.After riveting with different rivets,the changes of residual stress of plates have the same trend.The gray correlation analysis of evenness shows that evenness is highly correlated with rivet size and pier head height.The correlation calculation results of rivet size and pier head height on the deformation uniformity of rod were 0.608 and 0.596 respectively.The influence of rivet size on uniformity is greater than that of the upset head height.The tapered type rivet has a good effect on improving the deformation uniformity of rivet rod.