不同参数取值对复阻尼模型结构抗震性能的影响

结构动力分析中的复阻尼模型是在大量材料试验的基础上建立的,与粘性阻尼模型相比它能够真实的反映结构内未知的能量耗散。研究了应力无关复阻尼模型的损耗因子对结构震动响应和能量耗散的影响,以及应力相关复阻尼模型的初始损耗因子、疲劳极限应力、震动响应和能量耗散之间的关系。研究表明:应力无关复阻尼模型的动响应幅值随着损耗因子的增大而减小,能量耗散随着损耗因子的增大而增大,结构合适的阻尼比的选择是利用该模型进行有效动力分析的前提;与应力无关复阻尼模型相比,应力相关复阻尼模型的初始损耗因子的合理取值应当是一微小值(ε>0),它的取值对动力响应、能量输入和能量耗散的影响可以忽略;该模型的震动幅值随着疲劳极限应力的提高而增大,但最终收敛于某一稳定值;损耗因子和能量耗散随着疲劳极限应力的增加而减小,而能量输入随着疲劳极限应力的增大变化较小。该研究明确了复阻尼理论中的各个参数与响应、能量输入和能量耗散之间的关系,为复阻尼理论的进

Effect of different parameters on seismic performance of complex damping structures

The complex damping model used in structural dynamics analysis was suggested based on significant amount of experimental results.Compared with viscous damping model,this model can describe the unknown energy dissipation in actual structures.The effects of loss factor in stress-independent complex damping model on seismic response and energy dissipation were analyzed,and the relationships of initial loss factor,stress fatigue limit,seismic response and energy dissipation were discussed.It shows that the response magnitude with stress-independent complex damping model increases when the loss factor decreases,the seismic energy dissipation increases with increase of the loss factor.The appropriate selection of structure damping ratios is the premise of effective dynamics analysis.Compared with stress-independent complex model,the initial loss factor value of the stress-dependent model should be a tiny value(ε>0),but its magnitude has no effects on seismic response,energy input and energy dissipation.The response magnitude with this model theory increases with the stress fatigue limit increase,but it will eventually converge.The loss factor and energy dissipation increase with the stress fatigue limit increase,while the energy input has little change.The study makes the relationships of different parameters and energy input or dissipation very clear.The study provide a solid foundation or the further study of complex damping theory,development of equivalent viscous damping model and engineering application.