Meeting Abstract

10.11  Sunday, Jan. 4  The Effects of Dental Design on Fracture in Biological Tissues ANDERSON, P. S. L.; Univ. of Bristol Phil.Anderson@bristol.ac.uk

A primary purpose of dental structures is the fragmentation of food items. It is important to study gnathostome dental morphology in terms of the material properties of the food being consumed. Few studies have examined the interplay between dental shape and fracture mechanics in prey materials. This research utilizes a combination of physical experimentation and FEA modeling techniques to test how different dental blade morphologies affect the cutting mechanics of biological tissues. I tested the effects of blade morphologies on the cutting mechanics of a variety of biological tissues (including fish muscle, cuticle and plant stems and leaves) using a unique double guillotine testing device developed for this project. The double guillotine allows measurement of the work to fracture (energy) required to cut biological tissues and allows a wide variety of blade designs to be tested. FEA software is used to model the biological tissues and calculate internal stresses and strains which occur during cutting. The experimental and modeling results are compared to explore the interaction between blade shape, cutting energetics and fracture mode in biological tissues. Experimental results show that certain blade configurations can reduce the work fracture measured during cutting of biological tissues by up to 50% in comparison with straight blades. Aspects of blade design affect measurements of work to fracture to different degrees depending on the tissue type. Materials with a high poisson ratio, such as animal muscle, show much lower work to fracture measurements when the material is constrained by a bladed notch, as opposed to simply altering the blades approach angle. Results from the FEA models indicate that these differences may be partly due to differences in the primary type of strain within the materials during cutting.