| 摘要 |
PURPOSE:To make it possible to generate cracks in different directions and different lengths in a test piece whose surface has a concave part for developing fatigue cracks by holding the test piece between a pressure load plate that has a hollow part and a compression plate and supplying repeatedly pressurized liquid to the hollow part. CONSTITUTION:A test piece 11 that has a slit 12 where fatigue cracks will develop has its upper and lower faces respectively pressed by a compression plate 13 and a pressure load plate 14 with the slit 12 at the center of the pressing by the plate 14. As the test piece 11 is pressed with a constant load P through the compression plate 13 and the pressure load plate 14 by operating compression rods 15a and 15b from above and below, pressurized liquid is repeatedly supplied to the hollow section 16 through a fluid supply route 17 from a pressurized liquid supply tube 18. During this the pressure in the hollow section 16 is completely sealed by an O-ring 19 and a back-up ring 20. Desired fatigue cracks starting from the slit 12 develop due to repeated pressure P at the slit 12 of the test piece 11. |
