爆炸荷载作用下柔性动边界拱的动力响应分析

Analysis of Dynamic Responses of Arches with Flexible Supports Subjected to Blast Loads

实际工程中的拱结构并不是采用固支或简支等理想刚性支承,而是具有弹性支承、阻尼支承等柔性动边界。文中建立了具有动边界拱的力学模型,基于大变形动力微分方程并利用有限差分方法,研究分析了动边界拱在爆炸荷载作用下弹塑性动力响应。研究表明,柔性动边界对拱结构工作性能产生很大的影响,竖向弹性支承能够使短作用时间爆炸荷载下拱的内力峰值减小,并且使到达峰值的时间增加,阻尼支承能同时使结构的内力和位移衰减,因此可以利用柔性支承来提高结构的抗力。

Rigid supports like clamped and simple supports are not actually adopted at the ends of arches in the engineering, but flexible supports such as elastic supports, damping supports are adopted. The mechanical models of arches with flexible supports were established, considering elastic and damping supports and lumped masses at the ends of arches. Based on large deformation dynamic differential equations and finite difference method, the elastic-plastic dynamic responses of arches subjected to blast loads were studied. The analyses show that flexile supports have great effects on the performances of arches, vertical elastic supports can decrease internal force peaks of the arches and increase the time arriving peak at transient blast loads, and damping supports can attenuate internal forces and displacements, therefore, the resistances of arches can be increased by flexible supports.