Roundbreaking Research: Mechanical Stress Analysis and Tool Optimization in Wood Splitting for Domestic Firewood Production

Abstract

This thesis sought to produce an optimized maul to split large firewood rounds on site after felling, bucking, and limbing a standing tree, in order to facilitate transportation of the rounds without heavy equipment. Areas of optimization for this research were tool head geometry and composite handle design. A 13 kilogram steel prototype maul head with a wedge angle of 40◦ was fabricated. The splitting performance of this maul prototype was compared to that of the Fiskars X27 splitting axe on Quercus rubra and Robinia pseudoacacia rounds, and the maul prototype was found to outperform the Fiskars X27 splitting axe on large rounds. Handles which had previously fractured were analyzed to estimate peak impact stresses during splitting, and the impact force curve was approximated in a MATLAB simulation of the wood splitting process. Wilton Tools’ BASH composite sledgehammer handle technology was determined to be the best commercially produced striking tool handle design and was selected as the basis for handle optimization. Cantilever bending tests were performed on a Wilton BASH sledgehammer, and emulated in Creo Parametric 3.0 CAD with finite element analysis. The geometries of the handle and head were optimized to reduce and withstand peak impact forces during splitting. This project represents the first steps in the development of a novel and effective woodsplitting tool.