Evaluation for Fracture Toughness with Considering the Thermal Energy

열에너지를 고려한 파괴인성치 고찰

  • 박재실 (성균관대학교 대학원 기계공학과) ;
  • 김정표 (성균관대학교 대학원 기계공학과) ;
  • 석창성 (성균관대학교 기계공학부)
  • Published : 2001.11.01

Abstract

In the case of a crack propagation, a portion of the work of inelastic deformation near the crack tip is dissipated as heat. In order to understand the thermal effect on fracture toughness, tensile test was carried out using thermocouples to monitor the variation of temperature with SA516 Gr70. The experimental results show that the temperature of specimen was increased $3.6^{\circ}C$ at static load condition. And the thermal effect was investigated connected with the steady-state stress in the vicinity of a crack propagation in the elastic-plastic C-T specimen theoretically. And fracture toughness, the energy to make crack surfaces, presented correctively. The fracture toughness with considering heat at the blunting of the crack tip ws lower about 19.3% than that of ignoring heat. So, it is resonable to apply the fracture toughness with considering thermal energy and it would be good explanation for constraint effect depending on the configuration in the presence of excessive plasticity.

Keywords