柔性动边界梁的弹塑性动力响应分析  

ANALYSIS OF ELASTIC-PLASTIC DYNAMIC RESPONSES OF BEAMS WITH FLEXIBLE SUPPORTS

作　　者：宋春明[1] 王明洋[1] 王德荣[1] 

机构地区：[1]解放军理工大学工程兵工程学院,南京210007

出　　处：《工程力学》2008年第12期42-47,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(50578158)

摘　　要：实际工程中的梁结构并不是采用理想的刚性支承,而通常具有柔性动边界。该文建立了柔性动边界梁的计算模型,模型考虑了梁端有弹性支承、阻尼支承以及刚性块等情况,并利用有限差分方法对运动方程进行离散,研究分析了在动载作用下柔性动边界梁的弹塑性动力响应。研究表明:动边界对梁的变形和受力有很大的影响,与刚性支承相比,竖向弹性支承能够降低梁的振动频率,并且使梁的内力和相对位移幅值减小,从而提高结构的抗力,但提高抗力的效果与载荷作用时间的长短以及振动衰减的程度相关。Beams in practical engineering are usually supported by flexible supports, rather than rigid supports, The mechanical model of beams with flexible supports is established in this paper firstly, considering elastic and damping supports and lumped masses at the ends. Based on dynamic differential equations and using t-mite difference method, the elastic-plastic dynamic responses of beams subjected to dynamic loads are analyzed. The analyzing results show that flexible supports have significant effects on the displacements and internal forces of beams under dynamic loads. Vertical elastic supports tend to reduce the vibration frequencies and the crest values of internal forces and displacements, as a result, the resistances of beams are enhanced by flexible supports. But this advantage depends upon the duration of loads and damping.

关 键 词：振动理论 弹塑性动力响应 动边界 梁 弹性支承 

分 类 号：O327[理学—一般力学与力学基础] TU311.3[理学—力学]