| 摘要 |
There is provided a material testing machine measuring strain of a tube-like test piece by applying inner pressure and stress in a tube axis direction to the test piece. The material testing machine comprises: a plurality of radial direction displacement detection units that detect displacements of an outer circumferential surface of the test piece in a radial direction in a central portion of an effective length of the test piece; an axis direction displacement detection unit that detects a displacement in the tube-axis direction of the outer circumferential surface of the test piece in the central portion of the effective length of the test piece; and a calculation unit that calculates the strain in a circumferential direction and the tube-axis direction of the test piece in the central portion of the effective length, based on detection results by the plurality of radial direction displacement detection units and the axis direction displacement detection unit, wherein the plurality of radial direction displacement detection units respectively detect displacements at different directions around the tube axis of the test piece. |
