Establishment of unified fatigue design maps for different types of fracture mode of single-sided fillet welded T-joints
Establishment of unified fatigue design maps for different types of fracture mode of single-sided fillet welded T-joints
复制标题
单面角焊T型接头不同类型断裂模式统一疲劳设计图的建立
DOI：
10.1299/transjsme.15-00113
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
T. Naganawa
中科院分区：
文献类型：
--
作者：
Yasuki Kita;Atsushi Kitaguchi;T. Naganawa
对单面角焊T型接头试件进行了纯弯曲疲劳试验。施加两种载荷条件，分别在焊趾处施加拉应力和压应力，并测定了2×106次循环的疲劳强度。其次，用有限元方法模拟疲劳试验进行了裂纹分析。在分析中，用缝隙模拟了0.2 mm的初始趾尖裂纹和根部间隙，并计算了缝尖的张开位移。根据这些位移，计算了作用在最大主应力面上的应力强度因子。通过疲劳试验和裂纹分析的对比，估计了纯弯曲的断裂准则。将这些准则推广到同时施加拉伸和弯曲载荷的情况，并计算了每个根部间隙和焊趾处基于热点应力的断裂极限线。利用这些极限线和基于材料的强度，提出了可同时评估焊趾和根部间隙疲劳强度的断裂设计图。
Pure bending fatigue tests were conducted with single-sided fillet welded T-joint specimens. Two load conditions, which were given the tensile and compressive stresses in the weld toe, were applied, and fatigue strengths at 2×10 6 cycles were determined. Next, we conducted crack analyses simulating the fatigue tests by FEM. In the analyses, initial toe crack of 0.2 mm and root gap were modeled by slit, and opening displacements of the slit tip were calculated. From these displacements, stress intensity factors acting on the maximum principal stress plane were calculated. By comparing fatigue tests and crack analyses, fracture criteria for pure bending were estimated. These criteria were extended to the conditions in which tension and bending load were applied simultaneously, and fracture limit lines based on hot spot stress were calculated in each root gap and weld toe. By using these limit lines and material based strength, the fracture design maps that can be evaluated the fatigue strength of both root gap and weld toe at the same time are proposed.