Young's modulus from experiments on large beam deflections

Motivated by an industrial Research and Development project, this article presents the development of a teaching module that helps to motivate the discussion of published articles. This module is part of a new activity called Assessing Published Results for the Advanced Experimental Engineering senior course. Using theory, experiment and computation, the module explores the question of how to properly measure the Young's Modulus of cantilevered beams subject to external loads. At the end of the analysis, we conclude that using standard theory may create artifacts that could erroneously be interpreted as load-dependent changes in elasticity. Our analysis demonstrates conclusively that the Euler-Bernoulli theory artificially produces a load-dependent Young's Modulus, whereas the Elastica theory correctly returns a constant value.