循环荷载下岩石阻尼行为的试验研究

为了深入地了解岩石的阻尼特性，利用WDT–1500多功能材料试验机，对砂岩、砾岩和砂砾岩进行了循环荷载试验，研究了岩石的动剪切模量和阻尼参数对应力、应变幅值和应力水平的响应特性，得到了动弹性模量和阻尼参数随应力幅值、应力水平及含水率的变化规律，讨论了其变化机理。证实了双曲线关系能够描述分级循环荷载作用下岩石的应力-应变关系，得到了动剪切模量和阻尼比与动应力、动应变之间的关系，建立了不同应力水平和不同应力幅值条件下岩石的动剪切模量与阻尼比关系模型，结果表明该模型能够描述分级循环荷载过程中阻尼行为。

Experimental Research on Damping Behavior of Rock Subjected to Cyclic Loading

In order to discuss damping behaviors of rock under the stepped axial cyclic loading, WDT–1500 material testing machine is used to carry out sandstone, conglomerate and glutenite cycle loading tests in different stress levels and different stress amplitudes. The response properties of dynamic shear modulus and damping parameters about stress amplitude, strain amplitude and stress level under cyclic loading are realized. Also, the comparative analysis is made of damping behaviors under different loading conditions, whereby revealing that the dynamic shear modulus and damping parameters have their their varying laws with stress levels, stress amplitudes and moisture. Hyperbolic model is capable of describing the stress-strain relationship of rock under stepped axial cyclic loading. The interrelation of rock between dynamic shear modulus and strain and stress amplitude are obtained under stepped axial cyclic loading. A model of interrelation between dynamic shear modulus and damping ratio is proposed for rock in different stress levels and different stress amplitudes. The results show that the model is capable of describing the damping behavior of rock under stepped axial cyclic loading.