An Efficient Method of Modeling Material Properties Using a Thermal Diffusion Analogy: An Example Based on Craniofacial Bone

Abstract

The ability to incorporate detailed geometry into finite element models has allowed researchers to investigate the influence of morphology on performance aspects of skeletal components. This advance has also allowed researchers to explore the effect of different material models, ranging from simple (e.g., isotropic) to complex (e.g., orthotropic), on the response of bone. However, bone's complicated geometry makes it difficult to incorporate complex material models into finite element models of bone. This difficulty is due to variation in the spatial orientation of material properties throughout bone. Our analysis addresses this problem by taking full advantage of a finite element program's ability to solve thermal-structural problems. Using a linear relationship between temperature and modulus, we seeded specific nodes of the finite element model with temperatures. We then used thermal diffusion to propagate the modulus throughout the finite element model. Finally, we solved for the mechanical response of the finite element model to the applied loads and constraints. We found that using the thermal diffusion analogy to control the modulus of bone throughout its structure provides a simple and effective method of spatially varying modulus. Results compare favorably against both experimental data and results from an FE model that incorporated a complex (orthotropic) material model. This method presented will allow researchers the ability to easily incorporate more material property data into their finite element models in an effort to improve the model's accuracy.

The Feeding Biomechanics and Dietary Ecology ofParanthropus boisei

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Food mechanical properties and dietary ecology

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“…Most comparative morphological and palaeontological applications of FEA are concerned with the mechanics of the skull, and this is where most validation studies have focused. The skull is an incredibly complex structure, and many of its inherent variables have begun to be validated, including material properties (Strait et al 2005;Panagiotopoulou et al 2010;Davis et al 2011), muscle loadings , dentition and periodontal ligament (PDL; Marinescu et al 2005;Panagiotopoulou et al 2011), and the presence of cranial sutures (Kupczik et al 2007). Additionally, sensitivity tests have varied the model parameters to assess the manner in which they affect results, but without comparison with experimental strain data (Grosse et al 2007;Wroe et al 2007;Curtis et al 2008;Wang et al 2010;Grö ning et al 2011a).…”