列车激励下钢框架结构不同形式楼板振动特性分析

Analysis of Vibration Characteristics of Different Forms of Floor Slab of Steel Frame Structures Under Train Excitation

为分析列车激励下钢框架结构3种不同楼板形式的振动差异,使用ANSYS有限元软件建立轨道-路基-土体-钢框架结构耦合振动分析模型,为方便建模及提升求解效率,以刚度等效为原则分别对3种楼板进行合理的等效简化,并使用模态分析方法验证楼板等效模型的可靠性。通过瞬态动力分析得到列车激励下钢框架结构3种楼板形式的振动规律。结果表明:总体上组合楼板的振动位移峰值均大于另外2种楼板,但三者之间最大相差不超过2%;3个方向上组合楼板的加速度峰值总体上均大于另外两种楼板,在Y方向上,3种楼板的振动加速度峰值差距最大,最大达到15%左右;X、Y方向上3种楼板的振动加速度峰值随楼层的增加变化幅度较大,最大值均出现在顶层(第五层),Z方向上3种楼板的振动加速度峰值随着楼层的增加先增大后减小,最大值出现于第四层。

In order to analyze the vibration differences of three different floor forms of steel frame structure under train excitation,the coupling vibration analysis model of track,subgrade,soil and steel frame structure is established by using ANSYS finite element software.To facilitate the modeling and improve the solution efficiency,the three floor slabs are reasonably simplified based on the principle of stiffness equivalence,and the reliability of the floor equivalent model is verified by modal analysis method.Through transient dynamic analysis,the vibration laws of the three floor forms of steel frame structures under train excitation are obtained.The results show that in general,the peak value of vibration displacement of the composite floor is greater than that of the other two floors,but the maximum difference of the three floors is less than 2%;The peak acceleration of the composite floor in three directions is generally greater than that of the other two floors.In the Y-direction,the difference of the peak acceleration of the three floors is the largest,and up to about 15%;The peak vibration accelerations of the three floors in the X and Y-directions vary greatly with the increase of floor stories height,and the maximum value appears in the top floor(the fifth floor).The vibration acceleration peaks of the three floors in the Z-direction first increase and then decrease with the increase of the floor height,and the maximum value appears in the fourth floor.