正常工况下大型岸桥地震瑞利阻尼系数计算方法及试验研究

Calculation Method and Experimental Study of Rayleigh Damping Coefficients of Quayside Container Cranes in Normal Conditions

摘要:

针对大型岸桥地震响应分析中不同的瑞利阻尼系数会导致计算结果存在较大偏差，基于相似模型试验数据与仿真计算结果的对比分析，并综合考虑岸桥边界约束等因素，借鉴工程中常用的瑞利阻尼系数计算方法改进了岸桥结构的阻尼系数计算方法及频率选取方式。利用仿真方法和振动台模型地震试验对比分析不同瑞利阻尼系数下岸桥结构的动力响应，结果表明：瑞利阻尼系数计算方法和频率选取对岸桥结构地震响应的影响随着地震加强而提高，当加速度峰值为0.4g、0.62g，现有的阻尼系数计算方法得到的仿真结果与试验值之间的平均误差超过20%，而采用改进后的阻尼系数计算方法，岸桥地震仿真结果与试验值误差都在10%以内。

Abstract:

The use of different Rayleigh damping coefficients in the seismic response analyses of large quayside container cranes will generate very different results. By taking into account factors such as the boundary constraints of the container cranes, with reference to the method commonly used in engineering for calculating Rayleigh damping coefficients, we improve the method for calculating the damping coefficient and the frequency selection method for container crane structures based on a comparative analysis of similar model-test data and simulation results. Using the simulation method and shaking table tests, we compare and analyze the dynamic responses of the container crane structure under different Rayleigh damping coefficients. The results show that the influence of the methods used to calculate the Rayleigh damping coefficient and to select the frequency on the seismic response of the container crane structure increases with increases in the strength of the earthquake. When the peak acceleration is 0.4g or 0.62g, the average error between the simulation result and the test value obtained by the existing damping-coefficient calculation method exceeds 20%, whereas the error between them is within 10% when using the improved damping-coefficient calculation method.