摘要
运用有限元分析软件建立了钢桁架桥三维仿真模型,研究受拉力最大的斜拉杆螺栓裂纹尖端空间应力场,分析了主拉应力、应力强度和van Mises应力沿三个方向的变化规律,并拟合得到离面约束因子Tz与r/t(距裂尖距离/板厚)之间的关系式.研究结果显示裂纹尖端应力集中现象突出,应力集中系数大于4;裂纹表面与内部的扩展前沿不一致,斜拉杆翼缘板偏桁架外侧裂纹扩展更快,易在螺帽内形成具有隐蔽性的类椭圆裂纹;三维应力约束的影响范围在板厚的60%以内.
A refined 3-D fracture mechanics model containing a crack around a bolt hole is established for a simple-supported steel truss bridge,the crack growth is simulated,and the stress field near crack vicinity are studied,then the principal tensile stress,the stress intensity and MISES stress along three directions were analyzed,and the relation curve of Tz（out-of-plane constraint factor）and r/t（distance from the crack tip/thickness）was fitted.It turned out that the stress concentration factor was greater than 4and the out-of-plane constraint was occurred only in the coverage of 0.6times the plate thickness near crack.
出处
《武汉理工大学学报（交通科学与工程版）》
2014年第4期843-845,共3页
Journal of Wuhan University of Technology（Transportation Science & Engineering）
关键词
钢桁架桥
斜腹杆
裂纹尖端
应力场
离面约束因子
steel stress bridge
diagonal member
crack tip
stress field
out-of-plane constraint factor
