气爆荷载下弯曲构件动力响应数值计算

针对建筑结构内部气体爆炸荷载升压时间长、峰值压力小、压力峰值较多的特点，以等效单自由度方法为基础，通过将荷载、抗力矩阵化准确描述加载过程与结构动力特性，推导得到了气爆荷载下结构动力响应的数值计算方法，并与实验数据对比验证其准确性.研究发现:与实际气爆荷载相比，简化荷载因为忽略了荷载变化速率的影响使得计算的结构振动位移要小于实际情况，而阻尼的存在可以减少这种计算误差.相同峰值的荷载作用时间越长，对结构产生的变形能越大，结构的最大振幅与残余变形越大.初始速度与初始位移均会增加结构的振动挠度与残余变形，初始速度相当于结构额外受到了冲量荷载，而初始位移则相当于结构承受了外部静载. 

Numerical Calculation of Dynamic Response for Bending Members Under Gas Explosion

Gas explosion in building structures often presents the characteristics of long duration, small peak overpressure and multiple pressure peaks. Based on the equivalent single-degree-of-freedom method, the numerical calculation method of structural dynamic response under gas explosion was derived by the matrix of load and resistance and its accuracy and validity was verified by comparing experimental data. The results show that:compared with the actual gas explosion, the simplified explosion load will underestimate structural vibration displacement due to ignoring the change of load rate, and the existence of damping will reduce this calculation error. The longer the load duration of the same peak value is, the larger the deformation energy acting on the structure will be, thus the maximum amplitude and residual deformation of structural vibration will increase. Both the initial velocity and displacement will increase the vibration deflection and residual deformation of the structure. The initial velocity is equivalent to the additional impulse load on the structure, while the initial displacement is equivalent to the external static load on the structure.