改进的平均应力准则对钛合金断裂强度的评估(英文)

Fracture strength evaluation of titanium alloys using modified average stress criterion

结构完整性方法通常用来论证工程零件载荷传递的合理性。损伤模型对含尖缺口的钛合金断裂强度的预测取决于材料的无缺口强度以及缺口损伤区前的临界长度。损伤区的临界长度通常取决于材料、试样以及尖缺口的尺寸。平均应力准则作为一种应力断裂准则,常用来对含尖缺口的钛合金抗拉强度进行精确预测。基于不同厚度的中心裂缝钛合金的断裂数据,对平均应力准则进行改进。缺口(断裂)强度的预估值与测试结果接近,表明改进的平均应力准则可以简便地预测缺口的抗拉强度。

Structural integrity procedures were used to demonstrate the fitness for the purpose of engineering components transmitting loads. The prediction of the fracture strength of titanium alloys containing sharp notches through the damage model depends on the un-notched strength and the critical length of the damage zone ahead of the notch. In general, the critical length of the damage zone depends on the material, specimen, and size of the sharp notch. Modifications were made in one of the stress fracture criteria known as the average stress criterion for accurate prediction of notched tensile strength of titanium alloy specimen containing sharp notches. To examine the adequacy of these modifications, fracture data of center-cracked titanium alloys with various thicknesses are considered. The notched （fracture） strength estimates are found to be close to the test results. The modified average stress criterion is very simple to predict the notched tensile strength.