复杂阻尼结构阻尼模型研究

Damping model of a complex structure

复杂结构动力分析过程中,阻尼比的计算显得非常重要。由于复杂结构的阻尼模型具有特殊性,对如何确定阻尼比等参数,至今没有较好的理论和方法。针对由多种不同阻尼特性材料建造的复杂结构,提出了一种基于换算模态阻尼比的阻尼模型。通过复阻尼理论和模态应变能法,推导了换算模态阻尼比,并得到了换算模态阻尼比与各种材料阻尼比之间的关系。将所提出的方法应用于工程结构,该方法计算的动力响应与子结构瑞雷阻尼法相比,其精度更高,接近于单元阻尼比法的结果。由于其方法简单、物理意义明确,在复杂结构动力分析中具有广泛的应用前景。

Damping ratio is critical to dynamic analysis of complex structures.However,due to the specificity of damping model of complex structures,there are no perfect theory and method to determine damping ratio and so on.A damping model based on converted modal damping ratios was proposed for complex structures constructed with materials of different damping properties.With this model,the converted modal damping ratios were derived by using complex damping theory and modal strain energy method,and the relationship between the converted modal damping ratios and the damping ratios of materials was obtained.The vibration responses of an engineering structure investigated with the proposed method were more accurate than those using the substructure method with Rayleigh damping and agreed well with those using element damping ratio method.Because the proposed method had a simple mathematical expression and a clear physical meaning,it could be widely used in complex structure dynamical analysis.