钢桥腹板间隙出平面变形影响因素敏感性分析

Sensitivity Analysis of Factors Affecting Out-of-Plane Deformation at Web Gaps of Steel Bridges

钢桥腹板间隙处的出平面变形破坏是钢桥破坏的常见形式之一。通过有限元数值模拟的方法,计算了不同腹板间隙大小,腹板厚度,以及肋板刚度的情况下,腹板间隙处范式等效应力和出平面位移量的分布规律;采用敏感性分析方法,计算了最大范式等效应力和最大出平面位移量对腹板间隙大小,腹板厚度,肋板刚度的敏感性程度。提出参数变化范围内,系统特性对影响因素平均敏感度的概念。研究表明,最大范式等效应力对腹板间隙大小最敏感,最大出平面位移量对腹板厚度最敏感。在实际应用中,采用合适的腹板间隙大小可以使最大范式等效应力最小,通过增加腹板厚度可以同时减小腹板间隙处的最大等效应力和最大出平面位移量,肋板采用较柔性的材料,能够有效减少腹板间隙处的出平面变形。

The out-of-plane deformation and failure at the web gaps of steel bridges is always one of the common forms of steel bridge failure.In this paper,finite element numerical simulation method is used to calculate the distribution law of Von Mises Stress and out-of-plane displacement in web gaps of different length of web gabs,web thickness,and stiffness of ribs.Sensitivity analysis method was used to calculate the sensitivity of the maximum Von Mises Stress and the maximum out-of-plane displacement on web length,web thickness,and rib stiffness,and the average sensitivity parameters of the system properties within the parameter variation range were proposed.The concept shows that the maximum Von Mises Stress is obvious related to web thickness and the maximum out-of-plane displacement is sensitive to the stiffness of the material.It is recommended to adopt appropriate web gap size to reduce Von Mises Stress,properly increase the thickness of web to reduce both of stress and displacement,and use more flexible material for the ribbed plate to diminish the out-of-plane displacement in practical applications.