A Curvature-ovalization measurement apparatus for circular tubes under cyclic bending

In this paper, the authors report the design and construction of a new measurement apparatus, along with the result of its testing. This apparatus can be placed at the midspan of the circular tube specimen and is suitable for simultaneous experimental determinations of the tube curvature and ovalization of the tube cross section. For testing the newly designed apparatus, the tube specimen of AISI 304 stainless steel was bent cyclically. It has been shown that the actual curvature and ovalization of the circular tube subjected to bending can be directly measured by the apparatus.