롤러로 지지된 철제 피스톤 형식의 하중재하판의 개발

초록

Side restraint generated along the specimen/loading platen interface influences on the accuracy of the multiaxial test results. Therefore, the use of a proper loading platen is a crucial for the multiaxial test condition. This paper presents a new type of loading platen: steel piston supported by roller end and examines the occurrence of side restraint along the lateral boundary of the specimen. The rollers installed at the rear of the individual pistons are purposed to allow free movement of the pistons which will induce almost zero restraint along the loading directions. From the lateral boundary friction test, individual movement of steel piston clearly demonstrates the no occurrence of side restraint. The test results of rigid solid type steel platen show variable side restraint with confining stress. This result implies that the boundary condition of back analysis should be changed with confining stress.