复振型叠加法截断误差及改进

发布时间：2018-01-10 14:30

本文关键词：复振型叠加法截断误差及改进　出处：《振动工程学报》2017年04期 　论文类型：期刊论文

【摘要】：根据复振型叠加理论,对具有非比例阻尼特性的线性体系,分析了复振型截断误差的来源,给出了误差公式。与比例阻尼体系的高阶实振型响应类似,通过反应比表达式可以看出随着输入频率与自振频率比的减小,高阶复振型的响应也趋于荷载的静态响应。基于此推导出了与传统修正方法形式一致的复振型静力修正方法和振型加速度方法,同时根据复振型退化为实振型的条件(实部与虚部成比例关系)建立了实、复振型修正方法的统一。用数值算例对修正方法进行了验证,结果表明:复振型修正方法能够很好地提高振型叠加的计算精度,特别是当结构主要固有频率大于输入卓越频率时修正效果更为显著;还发现附加阻尼较大时,导致部分高阶振型自振频率减小,在一定程度上会降低修正效果。
[Abstract]:According to the complex mode superposition theory, the linear system with non proportional damping characteristics, analyzes the sources of complex mode truncation error, error formulae are given. The high Jieshi vibration type and proportional damping system response is similar to that of the reaction than the expression can be seen as the input frequency and reducing vibration frequency than the static response. Higher order mode tends to load. This is deduced complexmode static correction method and modal acceleration method is consistent with the traditional correction method based on complex mode according to the degradation conditions for real mode (the real and imaginary proportion) was established, unified complex mode correction method. A numerical example validated the correction method to the results show that the complex mode correction method can greatly improve the calculation accuracy of modal superposition, especially when the main natural frequency is greater than the input frequency of excellence When the correction effect is more significant; also found that additional damping is large, resulting in some high modes of vibration frequency decreases to a certain extent will reduce the correction effect.

【作者单位】：广州大学减震控制与结构安全国家重点实验室(培育);北京工业大学建筑工程学院;
【基金】：长江学者和创新团队发展计划资助项目(IRT13057)
【分类号】：O32
【正文快照】： 2.北京工业大学建筑工程学院,北京100124)引言对于线性振动体系,一般采用振型叠加方法进行动力分析。通常振型叠加法[1]利用较少的无阻尼(实)振型表达结构的位移模式,通过坐标转换得到规模较小的用振型广义坐标表示的运动方程。这种方法对于位移响应有较好的近似,但对于内力和

【相似文献】