| 摘要 |
PURPOSE:To hold a test piece at a specified position by wedge action, by inserting the test piece between a pair of holding tools, which are engages with the slant surface of a cross head, and moving the cross head and the holding tools in the opposite directions at an equal speed. CONSTITUTION:A holding apparatus 2H of an upper cross head 1H has a pair of facing holding tools 3L and 3R, which are engaged with the slant surface 4H of the cross head. A lower cross head has the same structure. A test piece is inserted between the holding tools 3L and 3R, and hydraulic pressure is applied to a hydraulic cylinder 5H by a control mechanism 9. Thus the holding tools are moved and the test piece is held by the wedge action. Thereafter, hydraulic pressure is applied to a lower hydraulic cylinder 5L and a hydraulic motor 8, and the holding tools and the cross head are moved in the opposite directions at an equal speed. The test piece is held without substantially moving the holding tools in the axial direction of the test piece. Therefore, a buckling load is not applied to the test piece. |
