Deformation capacity of 400 N/mm2 class structural steel under extremely large strains

To provide qualitative database for further studies regarding the evaluation of cyclic deformation capacities 400 N/mm2 class structural steel up to maximum strength as well complete fracture, strain-based loading tests were performed in low and extremely low-cycle fatigue regimes. Thirty-nine specimens employed tested with strain amplitudes range from ±2% ±12%. By using three different specimen configurations made lots materials, by performing axial (starting tensile compressive loads), influences lots, configurations, initial directions on strain-life curve could be examined. The experimental results indicated that hardening behaviors all occurred first several cycles, while smaller strains (3% or below) stabilized until failure. However, fractured a ductile manner without achieving stabilization when they subjected large tests. (up failure) exhibited linear relationship 10%. At larger amplitudes, capacity material reached its peak subsequently became nonlinear. Nevertheless, curves stress show continuous 12%.