基于势接触连续-非连续方法的双层叠梁开裂过程模拟  

Simulation of Fracturing Process in DoubleLaminated Beams Based on the Potential Contact ContinuumDiscontinuum Method

作　　者：王学滨 李继翔 杜轩 郑一方 WANG Xuebin;LI Jixiang;DU Xuan;ZHENG Yifang(Institute of Computational Mechanics,Liaoning Technical University,Fuxin 123000,China;College of Mechanics and Engineering,Liaoning Technical University,Fuxin 123000,China)

机构地区：[1]辽宁工程技术大学计算力学研究所,辽宁阜新123000 [2]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《防灾减灾工程学报》2024年第5期1011-1019,共9页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金面上项目(52074142)资助。

摘　　要：弱黏结岩层容易发生滑动和离层,进而引发灾害。为了检验自主开发的势接触连续-非连续方法中的无黏结叠梁模型并深入了解其破坏后的力学行为,针对三点弯双层叠梁开展研究,并考察了势接触力求解中法向刚度系数的影响。通过将两个岩层叠合在一起建立叠梁模型,二者发生嵌入,因而存在相互作用的势接触力。通过改变单梁叠放顺序,分别形成了上砂岩下泥岩叠梁和上泥岩下砂岩叠梁。除了考察了载荷-位移曲线、最大主应力云图,还考察了裂纹区段数目的演化规律,以深化对叠梁复杂力学行为的理解。研究结果表明:(1)双层叠梁的载荷-位移曲线能与有关的实验结果吻合。(2)上泥岩下砂岩叠梁的各单梁裂缝出现时刻晚于上砂岩下泥岩叠梁的;前者的第1次硬化和第1次软化阶段比后者的长;前者的第2次硬化阶段不如后者的明显;前者的第2次软化阶段不如后者的明显,呈明显脆性。(3)对于上硬下软叠梁,随着法向刚度系数的减小,第1和第2峰值载荷对应的位移均增大。(4)对于上软下硬叠梁,随着法向刚度系数的减小,载荷-位移曲线由双峰或多峰向单峰转变。Weakly bonded rock layers are prone to sliding and delamination,causing geological hazards.To test the self-developed unbonded laminated beam model based on the potential contact continuum-discontinuum method and obtain a deeper understanding of its mechanical behavior after failure,a study was conducted in three-point bending double-laminated beams,examining the influence of the normal stiffness coefficient in the potential contact force solution.By stacking two rock layers together,a laminated beam model was established,where embedding occurred between the two layers,resulting in interactive potential contact forces.By changing the stacking order of individual beams,laminated beams with sandstone on top and mudstone on the bottom and laminated beams with mudstone on top and sandstone on the bottom were formed.In addition to examining the load-displacement curves and maximum principal stress contour maps,the evolution of the number of crack segments was also studied to better understand the complex mechanical behavior of the laminated beams.The research results indicated that:(1)The load-displacement curves of the double-laminated beams matched the relevant experimental results.(2)The moment of crack appearance in each individual beam of the mudstone-on-top laminated beam occurred later than that in the sandstone-on-top laminated beam;the first hardening and softening stages of the former were longer than those of the latter;the second hardening stage of the former was less pronounced than the latter;the second softening stage of the former was less obvious,showing clear brittleness.(3)For the hard-on-top,soft-on-bottom laminated beam,as the normal stiffness coefficient decreased,the displacements corresponding to the first and the second peak loads increased.(4)For the soft-on-top,hard-on-bottom laminated beam,as the normal stiffness coefficient decreased,the load-displacement curve changed from double peaks or multiple peaks to a single peak.

关 键 词：弱黏结 三点弯 叠梁 开裂过程 势接触 连续非连续方法 

分 类 号：TU457[建筑科学—岩土工程]