Identification of crack location in metallic biomaterial cantilever beam subjected to moving load base on central difference approximation

Abstract

If not detected early, the cracks in structural components may ultimately result in the failure of the structure. This issue becomes even more critical when the component under investigation is a prosthesis placed in the human body. This study presents a crack location identification method based on the time domain in a cantilever beam of metallic biomaterials (CBMB). The absolute difference between the central difference approximation of the root mean square (RMS) of displacement of points on the cracked and uncracked beams was applied as a cracked location indicator. Captured time-domain data (displacement) at each node of the cracked and uncracked beams were processed into a central difference approximation of the RMS of displacement. Then, the crack could be detected by a sudden change of the cracked location indicator. The feasibility and effectiveness of the proposed method were validated by numerical simulations. The finite-element simulation of a CBMB with a transverse notch was analyzed in the numerical study. The notch or crack was detected along the beam under a moving load at various locations. A set of simulation experiments and numerical calculations was performed to determine whether the proposed identification method would accurately detect the location of a crack in a cantilever beam under a moving load compared to the location found by an exact solution method. The results showed that the proposed method was not only as able as the analytical method but also robust against noise: it was able to detect a crack precisely under 5% noise.

Keywords

• crack identification
• metallic biomaterials
• central difference approximation
• cantilever beam
• moving load