A three-dimensional curvature-based beam model for measuring mechanical properties on an automated bone testing system

Mechanically handling of compliant bio-structures has been attracting growing attention due to the needs to automate processing of natural products. To understand the effect of bio-structural deformation on the blade location/force in poultry industry where high yield breast meats are harvested at production speed, biomaterial properties must be obtained before a nominal bio-structure model can be built for lumped parameter control of the process. This paper proposes a simple yet effective approach for obtaining the mechanical properties of biomaterials with a beam-like structure. A 3D curvature based beam model (CBM) with all its state variables described in global coordinates is developed for analyzing the large deformation of a compliant beam. The computationally efficient model without significantly scarifying accuracy has been verified numerically against a finite-element model. To illustrate its practicality, the CBM with cantilever constraints has been employed to analytically determine the nominal values of the elastic modulus and fracture strength from eight chicken-clavicle samples. While this paper is written in the context of wing manipulation for automatic deboning process, the method can be used in other bioengineering applications involving flexible beam-like elements.