| 摘要 |
PURPOSE:To investigate the fatigue of a test piece of a material by controlling predetermined residual tensile strain and residual compressive strain so as to maintain these constant, and applying tensile stress and compressive stress at low repetitive cycles to the test piece. CONSTITUTION:Where the strain subtracting the strain by the Young's modulus of a test piece from the tensile strain when tensile stress is increased gradually from 9 goes equal to the predetermined residual tensile strain, the tensile strain of the test piece is stored in the 1st memory, and the difference between the actual residual tesnsile strain of the test piece when the tensile stress is decreased gradually after this and the predetermined residual tensile strain is determined and this is stored in the 2nd memory. Following to this, the stress is gradually increased or decreased with the compressive strain as well, and the compressive strain of the test piece is stored on the 3rd memory. The difference between the actual residual compressive strain of the test piece and the predetermined residual compressive strain is stored in the 4th memory, and thereafter, the correction by the contents of the 1st-4th memories are corrected at every repetitive application of the tensile stress and compressive stress. |
