摘要
对冷轧钢圆形连接点和矩形连接点的压印接头进行拉伸-剪切试验,研究连接点形状对接头拉伸-剪切性能的影响。并对圆形连接点压印接头进行疲劳试验。试验结果表明,两种接头拉伸-剪切强度和刚度相当。圆形连接点拉伸-剪切过程中的能量吸收值大于矩形连接点,矩形连接点的失效形式为上板拉脱失效。应力比R=0.5,当最大疲劳载荷为接头强度的95%时,接头循环寿命可以达到137万次,为80%时,可以达到疲劳极限500万次。疲劳失效形式为上板接头处产生裂纹,裂纹方向与加载方向大致呈90°。提出了圆形点压印接头的拉伸-剪切强度预测公式和疲劳寿命计算公式,拉伸-剪切强度公式的误差为6.9%。
Two types of clinched joint named round and rectangle joint respectively were conducted by tensile-shear tests,and affect of joint shape on tensile-shear performance were studied.Fatigue tests on round clinched joints were carried out.It can be seen that,tensile-shear strength and stiffness of two types of joints were very near.Absorption of joint in tensile-shear tests for round one is higher than rectangle one.Failure mode for rectangle joint is upper sheet pulled-out resulting in separation of two sheets.Under load ratio R =0.5,when maximum fatigue load is 95％ of tensile-shear strength number of cycles is about 1.37 million.Number of fatigue cycles is 5 million at 80％.Fatigue mode is fracture in upper sheet just around the joint.And direction of crack and loading is about 90°.Strength prediction formula and fatigue life prediction equation are presented for round clinched joint.The strength prediction formula is valid with error of 6.9％.
出处
《机械设计》
CSCD
北大核心
2013年第9期78-82,共5页
Journal of Machine Design
基金
国家自然科学基金资助项目(50965009)
