Strain measurement of softened Eucalyptus regnans wood during bending operation using a low-cost single camera optical method

Abstract

An important requirement for developing an understanding of wood bending mechanics is to determine the mechanical response of softened wood during bending. This involves experimentally measuring wood's deformation or strain. Many wood bending studies have been conducted over the past 80 years to increase the understanding and investigate methods of ultimately improving the wood bending operation. The majority of these studies investigated the particular type of method of softening, using minimum bending radius and quality as a measured response. However, there is sparse literature in the public domain that offers a means of gaining an understanding of the mechanics of a wood specimen during a bending operation. This paper introduces a low-cost optical-based method for measuring engineering strain in softened wood. The method requires minimal specialised equipment and has been successfully used to determine the engineering strain response of Eucalyptus regnans during the bending process.