Tensile and tear-type fracture toughness of gypsum material:Direct and indirect testing methods  

作　　者：Daniel Pietras M.R.M.Aliha Hadi G.Kucheki Tomasz Sadowski 

机构地区：[1]Lublin University of Technology,Civil Engineering and architecture department,Nadbystrzycka 40 str20-618,Lublin,Poland [2]Welding and Joining Research Center,School of Industrial Engineering,Iran University of Science and Technology(IUST),Narmak,16846-13114,Tehran,Iran

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2023年第7期1777-1796,共20页岩石力学与岩土工程学报（英文版）

摘　　要：In this context,four specimens,i.e.(i)circumferentially notched cylindrical torsion(CNCT),(ii)circum-ferentially notched cylindrical direct tension(CNCDT),(iii)edge notch disc bend(ENDB)and(iv)three-point bend beam(3PBB),were utilized to measure the modesⅠandⅢfracture toughness values of gypsum.While the CNCT specimen provides pure modeⅢloading in a direct manner,this pure mode condition is indirectly produced by the ENDB specimen.The ENDB specimen provided lower KⅢc and a non-coplanar(i.e.twisted)fracture surface compared with the CNCT specimen,which showed a planar modeⅢfracture surface.The ENDB specimen is also employed for conducting pure modeⅠ(with different crack depths)and mixed modeⅠ/Ⅲtests.KIc value was independent of the notch depth,and it was consistent with the RILEM and ASTM standard methods.But the modeⅢfracture results were highly sensitive to the notch depth.While the fracture resistance against modeⅢwas significantly lower than that of modeⅠ,the greater work of fracture under modeⅢwas noticeable.

关 键 词：GYPSUM Pure modesⅠandⅢfracture toughness Mixed modeⅠ/Ⅲ Circumferentially notched cylindrical torsion(CNCT)specimen Circumferentially notched cylindrical direct tension(CNCDT)specimen Edge notch disc bend(ENDB)specimen Experimental measurement Geometry and loading type effects 

分 类 号：TU45[建筑科学—岩土工程]