Experimental investigation of linear damping characteristics on granite and red sandstone under dynamic cyclic loading

Abstract

Damping is a significant dynamic characteristic used to describe rock vibration failures and plays an important role in various seismic engineering applications, specifically for evaluating stability of rock masses under forced vibration loading. In this paper, cyclic loading tests were carried out on sandstone and granite samples to study their damping characteristics. The effect of the selected influential indicators (stress level, strain amplitude and loading frequency) on the damping ratio and damping coefficient was studied. The damping parameters of sandstone and granite were calculated and the variability in the damping parameters as a function of stress level, frequency and strain amplitude were determined. The linear relationship between damping ratio, damping coefficient and strain amplitude was investigated. The results suggest that the relationship between the damping parameters and the strain amplitude could be expressed as a linear function. The influential indicators to the damping parameter of granite were sorted as follows: stress level > strain amplitude > frequency. The influential indicators of sandstone were sorted as follows: strain amplitude > stress level > frequency. Under a fixed-amplitude stress path, the damping ratio of granite was approximately 80% that of the sandstone and the damping coefficient is approximately 200% of that of the sandstone.

Keywords:

• Mechanical damping
• frequency
• stress level
• strain amplitude
• red sandstone and granite

Acknowledgment

The financial support provided by this sponsor is greatly appreciated.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study is sponsored by the National Natural Science Foundation of China (Grants No. 11902249 and 11872301), Natural Science Foundation of Shaanxi Province (Shaanxi Province Natural Science Foundation) (Grant No. 2019JQ395) and Education Bureau of Shaanxi Province | Scientific Research Plan Projects of Shaanxi Education Department in China (Grant No. 20JS093).