弹性半空间地基梁的水平动力等效刚度  

Horizontal dynamic equivalent rigidity of foundation beam on elastic half space

作　　者：王雪 周凤玺[1,2] WANG Xue;ZHOU Feng-xi(College of Civil Engineering, Lanzhou Univ. of Tech., Lanzhou 730050, China;Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education, Lanzhou Univ. of Tech., Lanzhou 730050, China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050

出　　处：《兰州理工大学学报》2020年第5期113-117,共5页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51368038);甘肃省陇原青年创新创业人才资助项目。

摘　　要：基于弹性动力学的基本方程、考虑弹性梁和弹性半空间的动力相互作用,建立力学分析模型,并利用Fourier积分变换,得到弹性半空间地基梁的水平动力等效刚度的解析表达式.通过数值算例分析地基梁的水平动力等效刚度及其阻尼的变化情况.结果表明:地基梁的水平动力刚度和阻尼系数不为常数,而是与弹性梁中传播的相速度有关,当相速为Rayleigh波的速度时,水平动力等效刚度达到峰值,此时弹性梁的纵向振动向弹性半空间传递的能量最大.水平动力等效刚度与弹性地基梁的频率和波数密切相关,随着波数增大,水平动力等效刚度的实部和虚部均相应增大.Based on the basic equation of elastodynamics and taking into account the dynamic interaction between elastic beam and elastic half-space,a mechanical analysis model is established.An analytical expression of horizontal dynamic equivalent stiffness of an elastic half-space foundation beam is obtained by using Fourier integral transformation.The variation of horizontal dynamic equivalent stiffness and damping of the elastic foundation beam is analyzed respectively by numerical examples.The results show that the horizontal dynamic stiffness and damping coefficient of the elastic foundation beam are not constant,but are related to phase velocity of the elastic foundation beam.When the phase velocity is equal to velocity of Rayleigh wave,the horizontal dynamic equivalent stiffness reaches the peak,and the longitudinal vibration of the elastic foundation beam transfers the maximum energy to the elastic half-space.The horizontal dynamic equivalent stiffness of the elastic foundation beam is closely related to the frequency and number of waves in the beam.With increase of wave number,the real and imaginary parts of the horizontal dynamic equivalent stiffness increase accordingly.

关 键 词：弹性半空间 欧拉-伯努利梁 Fourier积分变换 水平动力等效刚度 

分 类 号：TU311[建筑科学—结构工程] TU470