Uniaxial stress-strain curves from a bending test

Abstract

A method which can be used to obtain both tension and compression stress-strain curves from a single bend test was first proposed in 1910. Curiously, this apparently useful technique has been very little application since that time. For this reason, the present investigation was conducted to examine the merits and shortcomings of the test. Three materials which show different stress-strain curves in tension and compression, beryllium, cast iron and prestrained copper, were studied to test the versatility of the method. A special four-point bend fixture, designed to minimize loading errors, was designed for this study and is described. Generally, the stress-strain curves obtained from bending and conventional tests showed good agreement for strains less than about five percent. Finally, some advantages and disadvantages of the bending tests are pointed out.