張瑞金^*，謝里陽^*，張嘯塵^*
*（東北大學機械工程與自動化學院，沈陽 110819）

　　摘要：由于焊接工藝的原因，某車型橫梁底板與補板焊接深度小于補板厚度，在理論分析中，可以將底板與補板之間存在未焊透區域近似處理為等效板面裂紋。車體服役過程中，在垂直于裂紋面的交變應力作用下，初始裂紋可能會發生疲勞擴展，裂紋擴展進入邊梁翼板，可引發邊梁裂紋，影響車體結構安全。本文通過有限元數值模擬和疲勞裂紋擴展試驗，研究了含焊接缺陷的橫梁補板裂紋在Ⅰ型加載條件下的疲勞裂紋擴展規律，采用ANSYS 的APDL 程序化語言編程建立模型，并對其進行數值模擬分析，得到了在不同裂紋長度下應力強度因子，擬合出裂紋尖端的應力強度因子公式，得到橫梁底板-補板焊縫在不同水平的循環應力作用下的疲勞裂紋擴展壽命。
　　關鍵詞：焊接，疲勞裂紋，應力強度因子，擴展速率，有限元模擬
　　Fatigue Crack Growth Rate of Crossbeam Soleplate with Welding Defects
　　Zhang Ruijin,Xie Liyang,Zhang Xiaochen
　　（ Mechanical Engineering School, Northeastern University,Shenyang 110819,China ）
　　Abstract:Due to the reason of welding technology, the welding depth between the soleplate and the cover plate on Crossbeam is less than the thickness of cover plate. In theoretical analysis, this welding defect can be conservatively considered as an equivalent surface crack. In the serving life of aHigh-Speed Electric Multiple Units （EMU） Train, initial cracks may propagate under alternating fatigue stress. When the fatigue cracks extend into the edge plate, it will be very dangerous to the whole structure. Using the FEM simulation and fatigue crack propagation test, this paper studied the fatigue crack propagation process on the crossbeam with welding defects. On the basis of ANSYS APDL programming language, the stress intensity factors were calculated with different crack length, then the formula of the crack tip stress intensity factor could be fitted. Furthermore, fatigue crack propagation life could be got under different levels of cyclic stress.
　　Key words:Welding, Fatigue Crack, Stress Intensity Factor, Growth Rate,FEM Simulation
　　聯系方式
　　張瑞金：rjzhang@mail.neu.edu.cn

責任編輯：趙澤南

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