Volume 15, Issue 2 (March 1987)
A New Method of Measuring the Modulus of Elasticity of Material by Analyzing the Relation Between Loading Position and Displacement of a Beam Bent by a Traveling Load
This paper proposes a new bending method using a computer to obtain a modulus of elasticity of plastics close to those given by tension methods. In the new method, a beam is freely supported at its ends on spherical surfaces. A load of constant weight on the beam travels from one support to another, and the displacement of the undersurface of the beam is measured at a certain distance from a support. The modulus of elasticity is obtained so that the (loading) position-displacement (of a point on the beam) curve expressed by the equation of displacement of the beam, which is a function of the modulus, will best fit the experimental displacements.
An equation is proposed for the displacement with terms including beam deflection and a quantity proportional to load travel, and a method to calculate the modulus from the experimental displacements is given. Finally, the experimental system with the testing machine and the good results of the experiments are shown.