Abstract:
Bone’s Mechano-sensitivity is a wide area of research in computational mechanics. Bone cells are capable of sensing and responding to mechanical forces. However, modeling these forces requires a lot of working and assumptions. There is a strong mechanical connection between mechanical signals and bone behavior. Bone behaves strongest in compression and weakest in shear. The forces that are modeled either by using traditional physical testing methods or by using numerical techniques like Finite Elements vary according to the type of geometry and the loading conditions. Intricate geometries end up having complicated force patterns and poor prediction of actual forces if not assumed properly. Some bones break under lower stresses than others, however the repair after the breakage process is important to understand. The healing processes sometimes bring more strength to the structure than the actual one. This could be due to different mechanical forces which fit well than what bone experienced during breakage. This study, therefore looks into how mechanical strength changes after the healing process. Studying the mechanics of bone are to improve the understanding of how and why bone fracture. From an engineering viewpoint, fractures represent a structural failure of the bone whereby the forces and moments applied to the bone exceed its load-bearing capacity. In this study a positive correlation is carried out using both physical testing method and finite element modeling to investigate the mechanics of bones in terms of its strength, stiffness, behavior and the amount of damage as a result of external loading and vice versa after healing.
Author utilizes a physical testing method (Uniaxial Compression Loading) and Finite Element Modeling on bird bone (Femur) in both healthy and injured conditions. The bone was virtually repaired using image processing to ally with what is available in the literature on healing. The typical stress fracture occurs during load application, this load may produce a shear tension, resulting in eventual random rupture of bone which is the
xv
case in this study as well. Author found out that these compound stress fractures not only weakens the bone resorption process but also decreases the bone deposit mechanisms to heal the bone quickly. Additionally, author inferred that the repaired bone showed half the amount of stresses to that of the healthy bone hence twice the mechanical strength.
