干涉装配接头残余应力场数值计算研究

Numerical Study on Residual Stress Field of Interference Fit Assembly Joints

金属材料连接接头是航空结构的主要部件,该型接头在飞机服役过程中需满足疲劳耐久设计要求,以避免发生疲劳破坏,相关的疲劳寿命增强技术应用、工艺参数、疲劳寿命以及失效形式是设计、制造人员重点关注的问题。装配干涉量是接头抗疲劳性能提升的重要工艺参数之一。本研究对干涉装配工艺过程进行有限元建模,得到不同装配干涉量下孔周残余应力的分布规律。结果表明,考虑安装过程时,所产生的残余应力分布沿连接板厚度方向并不均匀,环向残余应力不始终为压应力状态,干涉装配安装孔入口位置、孔出口位置均处于环向残余拉应力状态,在承受疲劳载荷过程中易萌生疲劳裂纹。

Metal material connection joints are the main components of aviation structures.This type of joint needs to meet the fatigue durability design requirements during aircraft service to avoid fatigue failure.The application of related fatigue life enhancement technology,process parameters,fatigue life,and failure forms are key issues that design and manufacturing personnel pay attention to.Assembly interference is one of the important process parameters for improving the fatigue resistance of joints.This article conducts finite element modeling of the interference assembly process and obtains the distribution pattern of residual stress around the hole under different assembly interference quantities.The results indicate that when considering the installation process,the distribution of residual stress generated is not uniform along the thickness direction of the connecting plate,and the circumferential residual stress is not always in a compressive stress state.The interference assembly installation hole inlet and outlet positions are both in a circumferential residual tensile stress state,and fatigue cracks are prone to initiate during the process of bearing fatigue loads.