顶部水平撞击作用下钢墩柱等效碰撞力研究

Research on the equivalent impact force for steel columns under horizontal impact at column top

通过对钢墩柱的水平撞击试验,探讨了撞击质量和速度对碰撞响应的影响;基于ABAQUS/Explicit有限元软件模拟,进一步探究了试件长细比、锤头材质及轴压比对试件动力响应的影响规律。在上述基础上,基于能量原理,提出了一种计算水平撞击作用下钢墩柱等效碰撞力的方法。结果表明:碰撞力随撞击质量和速度增加而增大,且受撞击速度的影响更显著;随试件长细比减小,碰撞力峰值增大,墩顶位移减小;较小的轴压力有利于提高试件的抗撞击能力。试件在铝制和钢制锤头撞击下的动力响应相似,相比而言,在橡胶锤头撞击下响应明显减小。将该方法计算的等效碰撞力以拟静力的方式施加于墩柱,得到的墩柱应变与位移等响应与撞击作用下的响应峰值误差在15%以内。

By conducting impact tests on a steel column specimen,the influences of impact mass and velocity on the impact responses were explored.Numerical simulation of the impact test was carried out based on ABAQUS/Explicit,furthermore,the effects of specimen slenderness ratio,hammer material,and axial compression ratio on the dynamic response of the specimen due to impact loading were investigated.Based on the energy principle,a method for calculating the equivalent impact force for steel columns under horizontal impact was proposed.Results show that the impact force increases with the impact mass and velocity,and is more significantly affected by the impact velocity.With the decrease in specimen slenderness ratio,the peak impact force increases while the displacement decreases;a smaller axial pressure is beneficial for reducing the dynamic response of the specimen.The dynamic responses of the specimen under the impact of the aluminum hammer are similar to that of the steel hammer.In comparison,the responses under the impact of the rubber hammer are greatly reduced.When applying the equivalent impact force obtained by the proposed method to the impact position of the column,the errors of the calculated maximum responses such as strain and displacement of the column are within 15%compared to the corresponding responses under impact.