Finite Element Analysis of Hard and Soft Tissue Contributions to Thoracic Response: Sensitivity Analysis of Fluctuations in Boundary Conditions

Modeling costal cartilage using local material properties with consideration for gross heterogeneities

“…Previous computational studies have indicated that costal cartilage may play a significant role in the distribution of stress and strain throughout the ribcage when an external load is applied (Murakami et al, 2006;Oyen et al, 2005) due to its role as a mechanical coupler. The current study represents the first step towards the understanding of a link between the material properties of costal cartilage and the structural behavior of costal cartilage segments.…”

“…In situations where loading is applied over a limited area of the anterior chest, the costal cartilage dictates the coupling of the ribcage components, affecting the propagation of stress and strain to the ribs. This dictates the overall stiffness and deformation of the ribcage and the probability of injury to each of the ribcage components (Murakami et al, 2006;Oyen et al, 2005).…”

The effect of calcification on the structural mechanics of the costal cartilage

“…The sensitivity analysis presented here suggests that the structural stiffness of individual costal cartilage segments will increase with calcification. Murakami et al (2006) demonstrated that increasing the stiffness of the costal cartilage can increase the overall stiffness of the chest when subjected to a concentrated externally applied load (such as a seat belt), due to an increase in the number of ribcage structures recruited to bear load. Oyen et al (2005) demonstrated that increasing the stiffness of the costal cartilage can increase the ultimate stress in the ribs for a given amount of sternal displacement, likely affecting the risk and number of potential rib fractures.…”

“…The properties of the costal cartilage affect not only the structural mechanics of the chest, but can also affect the risk of injury to the chest under external loading. Using a finite element model of the chest subjected to loading by a diagonal shoulder belt, Murakami et al (2006) found that adding a stiff (1 GPa) outer shell to the costal cartilage increased the overall stiffness of the chest by 50%. Using a finite element model of a single rib-ring unit, Oyen et al (2005) found that increasing the stiffness of the costal cartilage from 10 MPa to 1 GPa increased the peak von Mises stress in the ribs by 63% when a concentrated, posteriorly directed displacement was applied to the sternum.…”

“…As automotive safety technologies become increasingly precise, evaluations of those technologies rely more on injury-predictive finite element models of the chest and the whole body (Stitzel et al 2003;Kent, Lee et al 2005;Murakami et al 2006). This has presented considerable challenges given the complexity and multitude of tissues within the chest.…”