Abstract：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.
2016, Vol. 37 
