钢管混凝土柱在冲击荷载作用下的损伤评估方法

为了建立侧向冲击荷载作用下钢管混凝土柱的损伤评估方法，以钢管混凝土柱近支座落锤冲击试验为基础，结合数值模拟和理论分析，研究预加轴力、冲击体质量及冲击速度对钢管混凝土柱损伤程度的影响. 选取冲击体质量和速度作为损伤评估主控变量，建立基于剩余承载力的损伤评估指标D的计算式，并划分损伤评估等级. 以典型钢管混凝土结构柱为例，通过仿真试算拟合其损伤评估曲线，并建立损伤评估的图解方法. 研究结果表明:冲击体质量和速度对钢管混凝土柱损伤程度的影响显著，预加轴力的影响呈现出变异性；D=0.3，0.5，0.7时的损伤评估曲线将坐标平面划分为4个面域，分别代表钢管混凝土柱发生轻度损伤、中度损伤、重度损伤及破坏失效；根据冲击体质量和速度的组合点与损伤评估曲线的位置关系，可以快速判定钢管混凝土柱的损伤程度. 

Damage Assessment Method for Concrete-Filled Steel Tubular Columns under Impact Loading

In order to develop a damage assessment method for concrete-filled steel tubular (CFST) columns subjected to lateral impact, the drop hammer impact tests are carried out on CFST columns near supports. By the use of numerical simulation and theoretical analysis, the effects of pre-loading axial force, impact mass and impact velocity on the damage degree of CFST columns are studied. The impact mass and velocity are selected as the main control variables of damage assessment for CFST columns. Then the calculation formula D of damage assessment based on the residual bearing capacity is established and the levels of damage assessment are defined. The damage assessment method is given by taking a typical CFST column subjected to lateral impact. The damage assessment curves are fitted by simulation and trial calculation, and then the graphic method for damage assessment is established. The results show that the impact mass and velocity have great influence on the damage degree, while the effect of pre-loading axial force on the damage degree has great variability. The damage assessment curves (D=0.3, 0.5, 0.7) divide the coordinate plane into four regions, which respectively represent the slight damage, moderate damage, severe damage and failure for CFST columns. According to the position relationship between the combination point of the impact mass and velocity and the damage assessment curves, the damage degree of CFST columns can be quickly determined.