搅拌摩擦焊中作用力对搅拌头疲劳寿命影响的模拟研究  

Numerical Simulation on Effect of Forces on Fatigue Life of Rotational Tool in Friction Stir Welding

作　　者：张利国[1] 杨鹏[1] 姬书得[1] 卓彬 马轶男[1] 栾国红[2] 

机构地区：[1]沈阳航空航天大学航空航天工程学部,辽宁沈阳110136 [2]北京航空制造工程研究所,北京100024

出　　处：《热加工工艺》2015年第17期155-158,164,共5页Hot Working Technology

基　　金：国家自然科学基金资助项目(51204111);辽宁省优秀人才支持计划项目(LJQ2012015)

摘　　要：利用ANSYS n Code Designlife建立了搅拌摩擦焊(FSW)过程搅拌头的疲劳模型。结合FSW过程中实测的搅拌头作用力载荷谱以及搅拌头扭矩公式,获得了搅拌头的作用力与疲劳寿命两者之间的关系,着重研究了前进阻力平均值与其周期性载荷幅值的大小对疲劳寿命的影响。模拟结果表明,前进阻力及其周期性载荷是造成搅拌头疲劳失效的主要因素,而侧向力与扭矩是次要因素;下压力有利于提高搅拌头的疲劳寿命。搅拌头的疲劳寿命随着前进阻力与前进阻力幅值的增加而减小。焊接参数的改变对搅拌头疲劳寿命的影响较大,但无明显规律。在FSW过程中,下压力平均值与前进阻力平均值的比值的增加有利于降低前进阻力周期性载荷的幅值,进而提高搅拌头的疲劳寿命。对于13mm厚的2024铝合金,当下压力平均值与前进阻力平均值的比值大于2时,搅拌头的疲劳寿命大幅度提高。The fatigue model of rotational tool during the fi＇iction stir welding process was established by ANSYS nCode Desigulife. On the basis of the load spectrum of forces on the tool and the expression of torque, the relation between the load and the fatigue life was obtained. The effects of the mean of forward resistance and the amplitude of cyclic load on the fatigue life were mainly investigated. The results of numerical simulation show that the forward resistance and its cyclic load are the major factors of fatigue failure of the tool, and the lateral force and the torque of tool are secondary factors. The longitudinal force is beneficial to increase the fatigue life of the tool. With the increase of forward resistance and its amplitude, the fatigue life of the tool increases. Changing the welding parameters influences the fatigue life greatly, but the law isn＇t obvious. During the FSW process, increasing the ratio of the longitudinal force to the forward resistance is beneficial to reduce the amplitude of cyclic load, which results in the increase of fatigue life. When 2024 aluminum alloy with the thickness of 13mm is welded, the ratio of the longitudinal force to the forward resistance should be more than 2 in order to increase the fatigue life of the tool.

关 键 词：搅拌摩擦焊 搅拌头 作用力 周期性载荷 疲劳寿命 

分 类 号：TG453.9[金属学及工艺—焊接]