| 摘要 |
PURPOSE:To improve working efficiency of the test, by inserting a core having rigidity so as to approximately contact with the inner surface of the tube material to be tested, and applying tensile loads in the circumferential directions by a tensile means so that the facing parts on the same circumference of the tube material to be tested are separated in the reverse directions. CONSTITUTION:A tension jig 3 is pulled through a loading device under the state the core 2 having the desired rigidity is inserted so as to approximately contact the inner surface of the tesst piece 1. Then a tensile load W is loaded on the test piece 1. In this case, the tensile load, which is evenly divided into two, works on facing test parts 1a and 1b on the same circumference of the test piece along the circumfrential directions. When the tensile load is increased, the test parts 1a and 1b of the test piece 1 are fractured. The required tensile strength of the test piece 1 in the circumferential direction can be obtained from the load and the like up to said fracture. |
