河南理工大学学报（自然科学版）2024，Vol.43Issue(5)：163-172,10.DOI:10.16186/j.cnki.1673-9787.2023070006
压缩荷载作用下岩石类材料裂缝扩展预测理论的改进及验证
Improvement and verification of crack propagation prediction theory for rock mate-rials under compressive load
摘要
Abstract
Objectives The objective was to improve the accuracy of crack propagation prediction for rock materials by addressing deficiencies in the traditional maximum circumferential stress criterion(MTS crite-rion),which disregarded the non-singular stress term(T-stress)in the crack tip's stress field and the crack geometrical properties.Methods Based on the conventional MTS criterion,a new fracture criterion for non-closed fractures in rocks was established by considering the effects of T-stress and fracture geometry properties on the fracture tip stress field.Uniaxial compression tests were conducted on rock specimens with non-closed cracks in the center.The predicted criterion values were compared with the measured crack angle(θ),and the influence of fracture geometry and T-stress on crack initiation and the crack tip stress field was analyzed to assess the validity of the proposed criterion.Results The results of the research indi-cated that only considering fracture geometry features led to an increase in the crack width-length ratio(b/a),causing a rise in the stress intensity factor(KI).This increase resulted in tension fractures forming due to tensile action at the fracture tip,thereby increasing the type Ⅰ cracks in the composite fracture.When the geometric characteristics of the crack and T-stress were introduced simultaneously,an increase in the crack width ratio(b/a)reduced the crack angle θ and increased the maximum peripheral stress(σθ)max.With the introduction of T-stress,the crack starting angle(θ)and the crack starting load are closer to the actual value,then the T-stress plays a crucial role in suppressing crack initiation.Additionally,the crack starting angle(θ)gradually transitioned from positive to negative cracking with the increase of the crack dip angle(β).Conclusions The crack initiation criterion,considering T-stress and crack geometry,can more accurately predict the crack initiation angle(θ)within the range of 0° to 60° of the crack dip angle(β).关键词
断裂准则/非闭合裂缝/T应力/裂缝几何特性/起裂角Key words
fracture criterion/non-closed crack/T-stress/crack geometric properties/crack initiation angle分类
建筑与水利引用本文复制引用
李修磊,刁航,陈臣,黄锋,凌天清,曾彬..压缩荷载作用下岩石类材料裂缝扩展预测理论的改进及验证[J].河南理工大学学报（自然科学版）,2024,43(5):163-172,10.基金项目
国家自然科学基金资助项目(52078090,42202322) （52078090,42202322）
全职博士后留渝资助项目(Z32200078) （Z32200078）
中国博士后科学基金资助项目(2018M633627XB) （2018M633627XB）
