Abstract: In order to study the effects of viscoelastic dampers on fatigue behavior of steel trusses, the equivalent stiffness of viscoelastic dampers was derived. Based on random load, and according to load’s power spectral density（PSD）, structure’s frequency response and the structure’s modal, the fatigue behavior of the steel trusses were calculated and compared. These working conditions included that there was no viscoelastic damper added to the structure and that there were viscoelastic dampers with different damping coefficients respectively added to the structure. The result indicates that viscoelastic dampers can extend the structure’s fatigue lifespan efficiently. It is found that with the increase of the damping coefficient, the structure’s fatigue lifespan increases at first and decreases thereafter. Therefore structure’s fatigue resistant ability can be optimized through the best choice of the damping coefficients.

Key words: vibration and wave, damper, simulation, fatigue

摘要： 为研究粘弹性阻尼器对平面网架结构疲劳性能的影响，先对粘弹性阻尼器等效刚度进行推导，然后，基于随机振动载荷，根据载荷功率谱密度函数（PSD）和结构的频率响应以及结构的模态，对平面网架结构添加粘弹性阻尼器和不添加粘弹性阻尼器，以及添加不同阻尼系数的粘弹性阻尼器时的疲劳寿命进行计算和比较。结果表明，阻尼器可以有效的减少随机振动荷载对网架结构的疲劳破坏。且随着阻尼系数的增大，网架结构的最小疲劳寿命呈现先增大，后减小的趋势。因此通过合理选择粘弹性阻尼器的阻尼系数大小可以优化结构的抗疲劳性能。

关键词: 振动与波, 阻尼器, 模拟, 疲劳