Nondestructive Evaluation of Mechanical Properties of Femur Bone

Abstract

In a human body, the femur is one of the strongest and longest bones and commonly fractured bone shown in the last decades, especially in elderly humans. Common femur fractures are caused due to violent trauma and severe accidents. The complex structure and response of the bone under dynamic loading conditions will provide extensive information about the mechanical properties of the bone. In this work, we use a non-contact measurement technique using a Position sensing detector (PSD) to measure the natural frequencies and their corresponding mode shapes. The bone sample excited by the impact hammer, and its response is measured using PSD. Sequential measurements are taken on the sample and base; we take the transfer function of the sample with respect to base to measure the natural frequency of bone. Mechanical property such as elastic modulus of the bone is evaluated using measured natural frequencies, and compared with numerical results. The Modulus of elasticity of the bone is found to be 14.8 GPa. Modal analysis was carried to evaluate the natural frequencies and corresponding mode shapes. Numerical results are found to be within 9% of the experimentally measured results. Random vibration analysis was done to emulate the real-time testing for the bone sample. The measured spectrum follows the numerical data. This experimental technique will aid in the nondestructive evaluation of the mechanical properties of the bone sample. Further,this nondestructive technique can be extended for various biological specimens for calculating the mechanical response.