行走和跳跃激励下木-混凝土组合简支梁的加速度响应分析

Analysis on Acceleration Response of Simply Supported Timber-concrete Composite Beam under Walking and Jumping Excitation

应用ABAQUS有限元软件对木-混凝土组合简支梁在行走和跳跃激励下的加速度响应进行了分析,探讨了步频、行人数量、跳跃频率以及跳跃人数对组合梁的峰值加速度的影响。结果表明:木-混凝土组合简支梁的峰值加速度随步频的增大而有所增大;当多个行人在组合梁上有规律地行走时,行走人数越多,组合梁的峰值加速度越大;对于非规律步行,组合梁的峰值加速度要远小于规律步行,且不会随着行走人数的增加而一直增大。此外,木-混凝土组合简支梁在跳跃激励下的加速度响应要大于行走激励,峰值加速度同样会随着跳跃频率的增加而增大;组合梁在非规律跳跃下的峰值加速度要小于规律跳跃,两种跳跃方式下的组合梁的峰值加速度都会随着跳跃人数的增加而增大。在有限元分析的基础上,提出了木-混凝土组合简支梁的振动舒适度设计应考虑行走和跳跃激励的建议。

Finite element modeling was conducted to analyze acceleration responses of simply supported timber-concrete beam under walking and jumping excitation with ABAQUS. The effects of some factors （ the stride frequency, the number of pedestrians, the jumping frequency and the population scale of jumping） on the peak acceleration of the composite beam were discussed. The results show that the peak acceleration of simply supported timber-concrete composite beam gets bigger with the increase of the stride frequency. When pedestrians walk on the composite beam regularly, the peak acceleration rises with increase of the number of pedestrians. However, the peak acceleration of the beam under irregular walking is much smaller, and when the number of pedestrians increases, the peak acceleration doesn＇ t keep rising. Besides, the acceleration response of the simply supported timber-concrete composite beam under jumping excitation is much bigger than that under walking excitation, and the peak acceleration of beam also get bigger with the increase of the jumping frequency. The peak acceleration of the beam under regular jumping is bigger than that under irregular jumping, and with increase of population scale, the peak acceleration of the beam rises under the two kinds of jumping. Based on finite element simulation, it is suggested that the design of vibration comfort of the simply supported timber-concrete composite beam should consider both the walking and jumping excitations.