移动荷载作用下简支钢-混结合梁的动力响应分析

Dynamic Analysis on Simply-supported Steel-concrete Composite Beams under Moving Loads

考虑钢梁与混凝土板之间的相对滑移,对钢-混结合梁基本动力方程进行推导,采用分离变量法得到简支结合梁自振频率与振型的解析解,利用正交条件,得到移动荷载作用下结合梁动力响应的表达式。将结合梁的自振频率以及移动荷载作用下的动力响应的理论分析结果与实测结果进行对比分析,结果吻合良好。分析结果表明:由于柔性抗剪连接件的存在,结合梁中钢梁与混凝土板之间发生相对滑移,其移动荷载作用下的振动方程形式更为复杂,表现出与普通梁不同的动力特性。

Considering the slip between the steel beam and concrete slab,the governing motion equations of steel-concrete composite beams were deduced with the direct balanced method of the composite beam theory.By variable separation approach,the analytical solutions to natural frequencies and mode shapes of simply-supported composite beams were obtained.Under the orthogonal conditions,the dynamic expression of composite beams under moving loads was obtained.The natural frequency and dynamic responses of the composite beam under moving loads were analyzed theoretically and then compared with the experimental results,consequently showing good agreement.The results show that due to the flexible shear connectors,the relative slip occurs between the steel beam and concrete slab of the composite beam,which makes the dynamic equations of the composite beam under moving loads more complex and produces different dynamic characteristics as compared with conventional beams.