CAJ | 학술논문

预裂的人字形切槽巴西圆盘(Pre-cracked chevron notched Brazilian disc，简称P-CCNBD)是将人字形切槽巴西圆盘(cracked chevron notched Brazilian disc，简称CCNBD)的切槽尖端再稍加切削制成直裂纹前沿的试样。利用霍普金森压杆对P-CCNBD砂岩试样进行径向冲击，完成I型动态断裂试验后再做数值分析得到岩石的动态断裂韧度。为了验证数值模拟的可靠性，先进行了无限平面中一条有限尺寸裂纹表面受冲击拉伸作用的动态有限元分析，结果表明，数值模拟的结果与Shi得到的结果非常吻合。将试验-数值法和他人的准静态法分别确定的砂岩的动态起裂韧度进行对比，两种方法得到的结果有一定的差异。采用试验-数值法，将比较成熟的直裂纹巴西圆盘(cracked straight-through Brazilian disc，简称 CSTBD)和P-CCNBD两种试样测得的结果进行对比，两者吻合较好。得到的动态起裂韧度都有随着加载率的增加而增大的加载率效应。分析了准静态法的缺陷，认为试验-数值法得到的结果更为合理。
예렬적인자형절조파서원반(Pre-cracked chevron notched Brazilian disc，간칭P-CCNBD)시장인자형절조파서원반(cracked chevron notched Brazilian disc，간칭CCNBD)적절조첨단재초가절삭제성직렬문전연적시양。이용곽보금삼압간대P-CCNBD사암시양진행경향충격，완성I형동태단렬시험후재주수치분석득도암석적동태단렬인도。위료험증수치모의적가고성，선진행료무한평면중일조유한척촌렬문표면수충격랍신작용적동태유한원분석，결과표명，수치모의적결과여Shi득도적결과비상문합。장시험-수치법화타인적준정태법분별학정적사암적동태기렬인도진행대비，량충방법득도적결과유일정적차이。채용시험-수치법，장비교성숙적직렬문파서원반(cracked straight-through Brazilian disc，간칭 CSTBD)화P-CCNBD량충시양측득적결과진행대비，량자문합교호。득도적동태기렬인도도유수착가재솔적증가이증대적가재솔효응。분석료준정태법적결함，인위시험-수치법득도적결과경위합리。
Pre-cracked chevron notched Brazilian disc (P-CCNBD) is made by slightly cutting the notch tip of cracked chevron notched Brazilian disc (CCNBD) into a straight crack front. The P-CCNBD specimens of sandstone are diametrically impacted by the split Hopkinson pressure bar, the experimental recordings are then used in the succeeding numerical analysis to get the mode-I rock dynamic fracture toughness. In order to verify the reliability of the numerical simulation, the dynamic finite element analysis for a finite crack in an infinite plate subjected to impact tension at crack faces is simulated first;the results of the numerical simulation are highly consistent with those in the literature. The results of our experimental-numerical method are compared with those of quasi-static method proposed by others, certain difference is observed. On the other hand, results of P-CCNBD are in good agreement with those of the more mature specimen (cracked straight-through Brazilian disc-CSTBD), both are determined with the experimental-numerical method. The derived dynamic initiation fracture toughness increases with increasing loading rate, demonstrating the loading rate effect. The drawbacks of the quasi-static method to test the dynamic fracture toughness are analyzed. The result obtained by experimental-numerical method is more reasonable.