BOLTS PULLING TEST. REVERSER FOR BOLTS TESTING

Abstract

The article describes developed device for performing pulling tests of bolts, including high-strength. Principle of reverser operation is change of sign of applied load – compression of press causes stretching of a bolt. Advantages of presented reverser are: reliability, mobility, small size, economical operation and simpleness. Reverser designs permit to perform bolt tests at any hydraulic press. Using the developed device, deformation diagrams were obtained for bolts of different strength class 8.8 steel 40Kh and 20G2R and 10.9 steel 40Kh. These diagrams may serve as basis for numerical modeling of bolts in software packages, and also manual calculation of yielding. Tests revealed a number of advantages of bolts made of steel 20G2R over 40Kh, due to which application of bolts made of steel 20G2R is recommended in assemblies of any level of responsibility.