摘要
岩石复杂的内部构造层次决定其动态破坏的复杂性,而能量转化是材料变形破坏的根本原因,研究岩石破坏过程中能量消耗的变化规律,有助于理解动载作用下岩石强度变化和整体破坏的本质特征。采用SHPB动力加载装置对不同预制裂纹长度半巴西圆盘试件进行加载,分别对岩石的起裂韧度、破碎吸收能和能量利用效率进行分析。结果表明:当裂纹长度一定时,岩石材料的起裂韧度和破碎吸收能随着加载率的增加而增加,具有明显的率效应;当加载率一定时,起裂韧度随着预制裂纹长度的增加而增加,与理论相符,破碎吸收能随着裂纹长度的增加而减少;能量利用效率随着加载率的增加呈现出先减小、后增大、再不变的趋势,而裂纹长度对能量利用效率的影响较小。
The complex internal structure of rock determines the complexity of dynamic fracture,and energy transformation plays a fundamental role in the process of rock deformation and fracture.Studying the variation of energy consumption during rock fracture will be helpful to understand the change of rock strength and the essential characteristics of the whole failure under the action of dynamic load.In this paper,the SHPB dynamic loading device is used to dynamically load the semi-Brazil disk specimens with different pre-crack lengths,and analyze the fracture toughness,absorption energy and energy utilization efficiency.The results show that when the crack length is fixed,the fracture toughness and absorption energy of the rock material increase with the increase of loading rate,which has obvious rate effect.When the loading rate is fixed,the fracture toughness increases with the increase of the pre-crack length,which is consistent with the theory;the absorption energy decreases with the increase of crack length;the energy utilization efficiency tends to decrease first,then increase and then remain unchanged with the increase of loading rate,while the crack length has little effect on energy utilization efficiency.
作者
孙友杰
戚承志
朱华挺
SUN Youjie;QI Chengzhi;ZHU Huating(Beijing Advanced Innovation Center for Future Urban Design,Beijing 100044,China;Beijing University of Civil Engineering and Architecture,School of Civil and Transportation Engineering,Beijing 100044,China)
出处
《施工技术》
CAS
2018年第A04期1230-1233,共4页
Construction Technology
基金
国家自然科学基金:准脆材料强度尺寸效应和应变率效应的内在关系研究(51478027)
岩体中慢速变形波的产生和传播演化规律研究(51774018)
973重大项目子课题:深水长线盾构隧道地震动力响应机理(2015CB57805)
大土木与地下建筑工程长江学者和创新团队发展计划资助(IRT_17R06)