基于极限载荷与断裂强度的5A06铝合金焊接缺陷安全性评定的数值方法研究 Numerical Method Study on Safety Assessment of Welding Defects of 5A06 Aluminum Alloy Based on Ultimate Load and Fracture Strength

本文建立了一种针对5A06铝合金带焊接缺陷平板的安全性评定的数值方法。首先采用极限载荷分析法建立了极限应力和裂纹长度的定量关系，从而获得失效评估曲线(FAC)。对130 mm厚的5A06铝合金对接焊接平板，采用SINTAP标准获得焊接残余应力分布和残余应力强度因子,并用虚拟裂纹闭合技术(VCCT法)计算工作载荷作用下的应力强度因子，建立了5A06铝合金失效评估图(FAD)。论文提出的数值方法能够对给定缺陷条件下的承载能力进行安全性评定；相反，在给定外载荷条件下，对缺陷的容纳限值进行确定。 In this paper, a numerical method for assessment the safety of 5A06 aluminum alloy strip with welded defects is established. First, the quantitative relationship between the limit stress and the length of the crack is established by the limit load analysis method, and then the failure assessment curve (FAC) can be obtained. For the 130 mm thick 5A06 Aluminum Alloy butt welding plate, welding residual stress distribution and residual stress intensity factor are obtained by SINTAP, and the stress intensity factor of the working load is calculated by the virtual crack closure tech-nique (VCCT method), then the 5A06 Aluminum Alloy failure assessment diagram (FAD) is estab-lished. The numerical method proposed in this paper can be used to evaluate the safety of the bearing capacity under the condition of a given defect. On the contrary, under the given external load conditions, the limitation of the defect can be determined.