移动荷载作用下桥梁动力响应分析

Analysis for Dynamic Response of Bridges Subjected to Move Loads

桥梁的振动状态是评价结构动力设计参数合理与否的重要指标。变截面梁可以提供更好和更合适的质量和应力分布,满足在建筑、机械、航空航天和其他工程创新应用中的要求。研究等高度矩形变截面均匀梁在移动荷载作用下的动力响应,具有一定的理论意义和实际应用价值。建立了移动载荷作用下,两端简支系统的控制方程,得到了精确的理论解,并给出了有限差分法和ANSYS有限元法的数值结果,三者互相验证,吻合良好。最后讨论了非均匀系数δ、车辆行驶速度c等参数变化对系统动力响应的影响。

The vibration state of bridge is a key index in evaluating whether the structural dynamic design parameters are reasonable.Beams with variable cross-sections may provide a better or more suitable distribution of mass and strength and therefore can meet special functional requirements in architecture,robotics,aeronautics and other innovative engineering applications.Dynamic responses of beams with constant height and variable cross-sections under moving vehicles are studied.It has both theoretical significances and practical application values.The control equation of the simple beam under moving forces is established,and the comparatively precise theoretical solution is obtained.Then the numerical verifications of both finite difference method and ANSYS finite element method are given.They all receive a good result.Finally,the impacts caused by the changes of non-uniform factor and vehicle speed are discussed.