2007 年 56 巻 12 号 p. 1177-1182
In order to accelerate the development of structural materials and improve reliability under an actual environment over extended and practical lifetimes, a multi fatigue testing system, the test efficiency of which is twelve times greater than that of the conventional fatigue testing system, has been developed.
The fundamental components of this system are (1) a unified hydraulic power unit, (2) six individual testing units, each of which has an actuator and a frame for accurate test control, (3) original software that enables stable control and has a graphical user interface with a labor-saving function, such as an automatic start function after elevating and holding the test temperature.
The cost of this system is very low, because of the elimination of the exclusive controller and unification of the hydraulic power unit.
Using this system, fatigue tests of six specimens can be simultaneously carried out with respective testing conditions, without interference among testing units, while other tests are still in progress. In addition, the multi fatigue testing system enables stable and accurate fatigue tests over a long period of time. Furthermore, the newly developed system can reduce the operating time remarkably, by employing convenient software. As a result, the evaluation period for the fatigue properties of materials could be remarkably shortened in comparison with the conventional fatigue testing system.
The reliability of the proposed fatigue testing system was verified based on the stability of the waveform and the load amplitude, the relative deviation among testing units, and the reproducibility of the S-N diagrams obtained by the conventional system. As a result, the proposed multi fatigue testing system was confirmed to provide high performance.