风沙粒子冲击钢结构涂层力学行为的理论与有限元分析

Mechanical behavior and finite element analysis of the steel structure coating in the wind and sand environment

利用接触力学理论和三维有限元分析了钢结构受到风沙粒子冲击后其涂层表面接触区应力、涂层内部应力、涂层与基体界面上应力的分布规律。分析结果表明:涂层表面径向应力在接触中心出现最大压应力,在接触区边缘出现最大拉应力,且在接触区边缘易发生环状撕裂破坏;在涂层内部,涂层对Z向应力的承受力较好;涂层内部剪应力的最大值出现在碰撞接触点的左下方和右下方,这两个位置易受到剪切破坏,在接触点和剪应力最大值之间的剪应力变化速度较大;涂层与基体界面上r/h为0~0.4时,Z向应力变化较小;在r/h为0.4~1时,Z向应力剧烈减小;r/h】1时,Z向应力基本保持不变;涂层与基体界面上剪应力最大值出现在冲击点附近,且冲击点附近剪应力变化较大,易引起剪切撕裂破坏。

Aiming at the impact of steel coating by sand, the contact mechanics theory and 3D-FEM are used to analyze the contact stress of the coating surface impacted by sand, coating internal stress and distribution rule of stress on coating and substrate interface. Results obtained show that the radial stress of coating surface reaches the maximum compressional stress at the contact zone and maximum tension stress at the edge of the contact zone, and annular tear damage happens at the edge of the contact zone. Inside the coating, the coating has a better endurance from the Z direction stress, the shear stress reaches the maximum value at the bottom-left and right of collision point, both two locations are vulnerable to shear stress, the change of velocity is bigger between the collision point and maximum shear stress. Z direction stress from the coating and substrate interface has a smaller change during the range of r/h=0~0.4. When r/h=0.4~1, Z direction stress decreases sharply, while after r/h>1, Z direction stress is steady. The shear stress from the coating and substrate interface reaches the maximum value near the collision point, and the shear stress changes greatly near the collision point and always happens tear damage by shear.