摘要
基于大变形动力控制方程并应用有限差分离散求解,对冲击载荷作用下框架结构的非线性动力响应进行了初步研究。通过对响应过程中轴力、弯矩、变形以及塑性耗能分布规律的细致分析,探讨了框架结构的非线性响应模式和变形机制。研究表明,冲击载荷作用下,撞击点处"驻定塑性铰"是动力响应过程的主要变形机制,而框架柱"塑性铰"或"塑性区"是响应过程的又一主要模式,且此变形模式的表现形式会随初始动能的差异而发生变化。为验证本文理论计算的准确性,数值计算结果与已有文献的实验数据进行了比较,两者吻合很好。
By employing large deformation governing equations and expressed them in the form of finite difference, the nonlinear dynamic response of frame subjected to impulsive load at its beam is investigated numerically. The deformation mechanism is discussed through exploration to the instantaneous distribution of axial force, bending moment and plastic work dissipation during early, transient stage of the response. It is showed that the ＂stationary hinge＂ located at the impact region is the main deformation mechanism in the whole course of the dynamic response. Comparatively, the mode of ＂stationary hinge＂ occurred at the joint of beam and column and the mode of ＂plastic region＂ occurred at the column are the other two deformation mechanisms in the duration of the dynamic response. In addition, the later two modes are influenced sensitively by the magnitude of the initial kinetic energy. To verify the theoretical predictions, a group of experiment data obtained from the high-speed photographs is presented and compared with the numerical results on the instantaneous profiles of the frame. The results show that present method is of good accuracy in predicting the dynamic behavior of impulsive loaded frames.
出处
《振动工程学报》
EI
CSCD
北大核心
2008年第2期107-114,共8页
Journal of Vibration Engineering
关键词
冲击载荷
框架结构
非线性
动力响应
大变形
impulsive loading
frame structure f nonlinear
dynamic response
large deformation
