A research was performed on thin metal sheet fatigue test under tension-
compression loading. A
restraint was applied to the
fatigue test in order to prevent the occurrence of unsteady
compression. To determine the effects of the
restraint on the stress in a specimen, the specimen surface strain was measured by an adhesive strain gage. The measured stress in specimen shows that the simple fixture is efficient to prevent the occurring of bending stress in the compression load condition. The stress measurements were performed under different fix forces. The results show that the fix force has no obvious effects on the applied axis tension or compression stresses of the tests. The restraint is designed to clip the center part of specimen and let the fatigue sensitive part free. The configurations of the fracture surfaces show that the fatigue failure started from the edge of the sheet specimen. That place is far from the fixture. Two kinds of metal sheets, aluminum and titanium, were used to perform the fatigue test with different machines for various lives or frequencies. The results were plot together with those of positive ratios for comparing. It is shown that the proposed fixture is efficient for fatigue test.