黏弹性阻尼器大变形性能试验研究

Experimental study of viscoelastic dampers subjected to large deformation

通过对黏弹性阻尼器缩尺试件进行不同应变幅值、加载频率和环境温度下的基本力学性能试验、老化性能试验以及低周、高周疲劳性能试验,研究试件在不同工况下的剪切存储模量、剪切损失模量和损耗因子等力学参数,及其力学性能的变化规律。其中,力学性能试验的应变幅值100%～420%;低周疲劳试验最大应变达300%。试验结果表明:黏弹性阻尼器力学性能与加载频率相关性较小,与温度相关性相对明显,随应变幅值的增加阻尼器表现出软化特征,但其损耗因子始终保持在比较高的水平;阻尼器在小位移和大位移下都有稳定耗能能力,可用于风振控制和地震响应控制;阻尼器表现出良好的变形能力,在200%大应变下仍保持稳定的力学性能,应变420%时仍未破坏。

This paper mainly presents an experimental study on a new type viscoelastic damper, with better energy dissipation capacity and stability. Shear storage modulus, shear loss modulus and loss factor were measured under different loading schemes, to study the variation of the viscoelastic damper properties. The tests used reduced scale specimens. Displacement control and sinusoidal loading schemes were used. The mechanical properties of the damper for various strain amplitudes, loading frequencies and ambient temperatures were investigated. Aging tests, low cycle and high cycle fatigue tests were also conducted. Particularly, the low cycle fatigue property under a strain of 300% and mechanical properties under strains of 100% to 420% were investigated. Experimental results show that the dependency of the damper＇ s mechanical properties on frequency is small, while that on temperature is relatively significant. The energy dissipation capacity is stable under both large and small displacements, which means the damper can be used both for wind vibration control and earthquake resistance. It is also found that the damper exhibits stable behavior under strain of 200% , and does not fail under the strain of 420%.