Accumulation of wind induced damage on bilinear SDOF systems
Accumulation of wind induced damage on bilinear SDOF systems
复制标题
双线性单自由度系统风致损伤的累积
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
H. Hong
中科院分区：
文献类型：
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作者：
H. Hong
非弹性结构在风作用下的永久变形累积的评估对于建立一个标准来选择一个减小的设计风荷载和在风工程中结合有益的延性行为是很重要的。本文对双线性单自由度（SDOF）体系的永久变形累积和延性需求进行了参数研究。采用Newmark法对人工生成的风速时程进行了非弹性单自由度系统的动力分析。仿真结果表明，归一化损伤率的平均值高度依赖于振动的固有频率。如果阻尼比大于5%，则该平均值对阻尼比相对不敏感。与永久变形的积累相关的热散射是非常显著的。如果屈服强度与预期峰值响应的比值较小，则考虑后屈服刚度可以显著减少永久变形的累积。研究结果还表明，如果单自由度体系设计成能减小脉动风引起的峰值响应，则柔性结构在一小时内的风荷载作用下的延性需求可以远小于刚性结构或阻尼比较大的结构。
The evaluation of the accumulation of permanent set for inelastic structures due to wind action is important in establishing a criterion to select a reduced design wind load and in incorporating the beneficial ductile behaviour in wind engineering. A parametric study of the accumulation of the permanent set as well as the ductility demand for bilinear single-degree-of-freedom (SDOF) systems is presented in the present study. The dynamic analysis of the inelastic SDOF system is carried out using the method of Newmark for artificially generated time history of wind speed. Simulation results indicate that the mean of the normalized damage rate is highly dependent on the natural frequency of vibration. This mean value is relatively insensitive to the damping ratio if the damping ratio is larger than 5%. Thernscatter associated with the accumulation of the permanent set is very significant. The consideration of the postyield stiffness can significantly reduce the accumulation of the permanent set if the ratio of the yield strength to the expected peak response is small. The results also show that the ductility demand due to the wind action over a period of one hour for flexible structures can be much less than that for rigid structures or structures with larger damping ratio if the SDOF systems are designed with a reduced peak response caused by the fluctuating wind.