采用铝锂合金2198-T8,对未来搅拌摩擦焊接机身整体壁板的结构形式进行了设计,并把机身整体焊接壁板的结构形式简化为2种典型试验构型.采用中子衍射方法测得铝锂合金2198-T8单焊缝和双焊缝板的残余应力分布,并对2种试验件的残余应力分布进行了研究；对2198-T8母材和2种典型焊接试验件进行疲劳试验,测得不同尺寸的试验件裂纹扩展速率,并进行对比分析.采用ABAQUS软件建立了有限元数值计算模型,计算出2种情况下由残余应力引起的应力强度因子(Kresidual),研究了残余应力对于疲劳各参数的影响,采用Newman闭合模型计算出2种模型的疲劳寿命,并和试验寿命相对比.试验和数值结果表明:双焊缝试件的疲劳寿命比单焊缝试件长4倍；残余应力的存在改变了疲劳参数分布.%Al-Li alloy 2198-T8 was chosen to be used. The friction stir welded integral panel for fuselage application was designed and simplified into two typical testing samples. Residual stress profiles in single weld sample and double weld sample were respectively measured by neutron diffraction method. The distribution of residual stress was analyzed. Fatigue tests of two samples and parent material were performed and crack growth rates were measured and compared. In order to study the effect of residual stress, the finite element model was built and Kresidual of each type was calculated. Kresidualeffects on fatigue parameters were analyzed, and Newman closure model was used to calculate fatigue lives, which were compared with the experimental lives. It was shown that: the fatigue life of double weld sample is four times than that of single weld sample; residual stresses changed the distributions of fatigue property parameters with crack growing.
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