摘要
基于模态叠加理论,通过桥梁多个截面处加速度响应数据,计算得到桥梁受移动荷载作用下的模态加速度.根据d'Alembertian原理,桥梁截面任意时刻的动弯矩可看作是任意时刻受惯性分布力和移动荷载作用下的静弯矩.利用影响线,建立起移动荷载与弯矩之间的关系,提出了一种利用弯矩影响线识别移动荷载的方法.算例表明,当荷载只有一个时,可由单点弯矩直接识别,当有多个移动荷载时,可基于多个截面的弯矩数据,利用最小二乘法可以有效的识别出任意时刻作用于桥梁上的移动荷载值.该方法避免了求解桥梁的动力学微分方程,识别精度高且过程简单,适合于工程应用.
Based on the modal superposition theory,the second order derivative of the modal coordination is firstly obtained from the acceleration of the bridge at several sections. The inertia force of the bridge is then expressed as distributed load by means of the d＇Alembertian theory. Using the bending moment influence line of the bridge,the relationships between the moving load and the moment is proposed. The moving force can be obtained at any time points through the developed formula. Case studies show that this proposed method performs high accuracy in identifying time-varying as well as constant moving force. Moreover,this method doesn＇t need to deal with the ill-condition due to matrix singularity,which makes it in high efficiency and appropriate for engineering application.
出处
《动力学与控制学报》
2016年第2期182-185,共4页
Journal of Dynamics and Control
基金
国家自然科学基金资助项目(51108047)
厦门市科技计划项目(3502Z20143028)~~
关键词
荷载识别
影响线
移动荷载
模态叠加原理
load identification
influence line
moving force
modal superposition theory
