门式框架结构的瞬态波动响应和自振特性研究

摘要

Here,transient responses and natural vibration characteristics of portal frames were studied under shocking load with the reverberation-ray matrix method (RRMM).Firstly,the node displacement compatibility conditions and force equilibrium conditions were established under the local coordinate system.The dynamic response function of a portal frame was obtained with RRMM under the action of a square wave impulse exciting load.Afterwards,the transient response of the portal frame under the action of a unit impulse was obtained using the inverse fast Fourier transformation (IFFT) and the convolution transformation.Furthermore,natural frequencies and modal characteristics of the portal frame were discussed.%研究门式框架结构在瞬态波动作用下的动力响应求解和自振特性分析问题.建立了局部坐标系下节点位移协调条件和力平衡条件,借助回传射线矩阵法,得到了方波脉冲激振力作用下的门式框架结构的动力学响应函数.在此基础上,通过离散Fourier逆变换和卷积变换,得到单位脉冲作用下框架结构的瞬态波动响应,并进一步探讨了门式框架结构的自振频率和模态特征.