Mechanical responses and acoustic emission behaviors of coal under compressive differential cyclic loading(DCL):a numerical study via 3D heterogeneous particle model
Zhengyang Song1
Yunfeng Wu2
Yong Zhang3
Yi Yang3
Zhen Yang2
1.State Key Laboratory of Water Resource Protection and Utilization in Coal Mining,Beijing,China;Department of Civil Engineering,University of Science &Technology Beijing,Beijing 100083,China;State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,China2.Department of Civil Engineering,University of Science &Technology Beijing,Beijing 100083,China3.State Key Laboratory of Water Resource Protection and Utilization in Coal Mining,Beijing,China
摘要：The stability of coal walls(pillars)can be seriously undermined by diverse in-situ dynamic disturbances.Based on a 3D par-ticle model,this work strives to numerically replicate the major mechanical responses and acoustic emission(AE)behaviors of coal samples under multi-stage compressive cyclic loading with different loading and unloading rates,which is termed differential cyclic loading(DCL).A Weibull-distribution-based model with heterogeneous bond strengths is constructed by both considering the stress-strain relations and AE parameters.Six previously loaded samples were respectively grouped to indicate two DCL regimes,the damage mechanisms for the two groups are explicitly characterized via the time-stress-dependent variation of bond size multiplier,and it is found the two regimes correlate with distinct damage patterns,which involves the competition between stiffness hardening and softening.The numerical b-value is calculated based on the mag-nitudes of AE energy,the results show that both stress level and bond radius multiplier can impact the numerical b-value.The proposed numerical model succeeds in replicating the stress-strain relations of lab data as well as the elastic-after effect in DCL tests.The effect of damping on energy dissipation and phase shift in numerical model is summarized.
机标关键词：particleacousticloadingemissionstudymodelbehaviorscoal
论文发表日期：2023-06-28
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：19( 136-154 )
英文信息