大尺寸异种钢焊接管板结构低周疲劳行为研究

基于有限元方法对承受交变载荷的大尺寸异种钢焊接管板结构的应力应变场分布与变化的分析结果,预测了疲劳裂纹的产生位置,并进行了相应的疲劳试验研究.结果表明,焊接接头的受拉表面和受压表面焊趾部位分别为所在表面的最大应力和应力幅的峰值位置,且由于在第一个循环周期加载过程中产生塑性变形,导致稳定循环加载期间两侧焊趾部位均承受拉-...

Low-cycle Fatigue Behavior of Large-size Dissimilar Steel Welded Tube-plate Structure

Based on the FEM analysis of the distribution and variety of the stress and strains of the large-size dissimilar steel welded tube-plate structure under cyclic loading,the location of fatigue crack initiation of this structure were predicted,and low-cycle fatigue test was performed to verify the prediction and to study the cracks propagating paths.The results indicated that the weld toes linked to the two surfaces of the plate were the positions with the peak values of the maximum stress and the stress amplitude.The plastic deformations in the first loading cycle introduced the tensile-compressive repeated stress cycle at the weld toes during the subsequent loading cycles.It induced the fatigue cracks initiating at the weld toes linked to the two surfaces of the plate respectively.After initiating from the surfaces,the cracks propagated along the fusion lines with a short distance then turn into the base metal in the sections vertical to the surfaces.The depth of the crack initiating from the compressed surface was shorter than the one from the tensioned surface.