The pendulum waves in blocky rock masses exhibit nonlinear characteristics,making it diffi-cult to interpret their spectral features and the mechanism of quasi-resonance phenomena.To address this issue,a nonlinear vibration model of pendulum wave that considers cubic terms is established.The ap-proximate analytical solution of multi degree of freedom strong nonlinear vibration is obtained by using the improved L-P method and the mode superposition method.This,to a certain extent,explains the nonlin-ear phenomenon mechanism of pendulum wave in blocky rock mass observed in the experiments.The re-sults show that the vibration frequency can be expressed as high order polynomials of the input energy and changes non-monotonously as the energy increases.The ratios between the resonance frequencies are relat-ed to the system structure and are approximately equal to integer multiples of √2.By establishing a hierar-chical structure model for pendulum waves,it is concluded that quasi-resonance serves as an indicator of transitions between pendulum waves across different-sized blocks.
关键词
摆型波/强非线性/改进L-P法/块系岩体/准共振
Key words
pendulum waves/strong nonlinear/improved L-P method/blocky rock mass/quasi-resonance
维普
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