【摘要】 爆破地震动与天然地震动相比,具有震动频率高、强度衰减快、震动持续时间短等特点,结构受到的爆破震动激励是非一致的,而目前对于结构在爆破震动非一致激励下的响应研究很少。为此,采用Lagrange插值,实现现场爆破测震数据的非一致激励加载,进而利用动力有限元软件LS-DYNA,模拟并分析一个四层普通砖混结构于不同激励方式(一致激励、多点激励、非一致激励)下结构响应的差异,分析了同一种激励方式下,爆破震动荷载信号震幅、主频的变化对结构响应的影响。此外,还研究了非一致激励条件下结构各层楼板震动的峰值速度之间的变化规律。研究结果表明:同样荷载同种激励方式下,墙体易首先发生破坏;较高频率震动荷载宜采用非一致激励;结构中各层楼板的峰值速度基本随着楼层的增加而增加。更多还原

【Abstract】 Comparing with the case of natural seism,the artificial blasting vibrating is of the characteristics of higher frequency,faster strength attenuation and shorter shaking duration and the blasting vibration excitation on structures is non-uniform.By using Lagrange interpolation,the non-uniform excitation loading in accordance with field-measured data was achieved.Then the dynamic finite element software LS-DYNA was used to simulate and analyze different responses of a four-storey masonry structure under different excitation ways(uniform excitation,multi-support excitation,non-uniform excitation).The effects of different magnitudes and main frequencies of blasting-vibration on structure responses under the same excitation way were analyzed.The regulation of vibration peak velocity distribution on each storey under non-uniform excitation was also studied.The results indicate that masonry walls will be destroyed most easily under the same way of load excitation.The non-uniform excitation model is rather suitable to be adopted in the case of higher frequency excitation.Vibration peak velocity of each storey in structure increases with the raise of storey height.更多还原