| 摘要 |
PURPOSE:To maintain the displacement quantity of a test piece constant automatically and make it possible to obtain data over a long period of time by connecting the test piece to one end of a lever member, hoisting a storage tank contg. liquid at the other end, and adjusting the volume of the liquid in this storage tank. CONSTITUTION:While a latch 9 is held engaged, a prescribed amt. of water W is injected into a storage tank 5. When the latch 9 is disengaged, a lever member 3 is turned and a bar 11 is pulled upward, by which tensile load is applied upon a test piece 15 and a strain is generated therein. The displacement thereof is detected as quantity of electricity by a displacement converter 30, and further this is converted to an air pressure by a converter. By this air pressure, a control valve 36 is set at a prescribed opening. When the strain loses constancy, the equilibrium state of a measuring device is broken and the opening of the valve 36 changes. A prescribed volume of the water is discharged from the tank 5 by this, and since the load decreases, the tensile force acting upon the test piece 15 decreases accordingly, thus while the strain is maintained constant, the stress is relieved. The tensile force acting upon the test piece 15 is displayed on a recorder 37, and the characteristics of the test piece 15 are evaluated by investigating the stress relief curve thereof. |
