Experiment Study on the Growth of Strain by Thermal Ratchet Mechanism

Abstract

There are many cases that a permanent deformations called plastic flow take place in the materials of severely heated parts of thermal engined and etc. caused by the ratcheting superposition of thermal and mechanical stress. In this paper, the ratcheting is first classified in various types of thermal load, and then, those elongation rates are theoretically analysed. Moreover, several experiments were performed in order to check whether the theoretical explanations were reasonable or not, using thin tubes which are heated rotationaly or alternatively from outside, while they are pulled in axial direction. Besides those, the existence of critical conditions for the plastic flow generation was also studied theoretically and experimentally. Recently, as ratchet problems are becoming the subject of wide interest, it is desirable that this study can be of any service to further investigations.