考虑支点摩擦的压实黏土ASCB试样Ⅰ-Ⅱ复合型断裂特性研究OA

To investigate the influence of support friction on the mixed-mode Ⅰ-Ⅱ fracture character-istics of compacted clay using asymmetric semi-circular bending(ASCB)specimens,the ABAQUS finite element software was employed to study the effects of dimensionless crack length(a/R),sup-port span ratio(S2/R),and support friction coefficient(f)on the dimensionless stress intensity factors YⅠ and YⅡ and the dimensionless T-stress(T*).In addition,three-point bending tests were con-ducted on compacted clay to examine the effect of support friction on fracture toughness.The results indicate that under non-pure mode-Ⅱ loading,YⅠ,YⅡ,and T* exhibit a certain degree of reduction with increasing f.Under pure mode-Ⅱ loading,increased f induces stress concentration,altering the stress state at the crack tip and resulting in a transition from pure mode-Ⅱ to mixed-mode Ⅰ-Ⅱ load-ing.The three-point bending tests revealed that when support friction is considered,the use of tradi-tional stress intensity factors results in an overestimation of fracture toughness values.Therefore,when employing fixed supports in three-point bending fracture tests on compacted clay,fracture tough-ness must be calculated based on dimensionless parameters corrected for friction.