Numerical simulation and non-destructive characterization of material property and defect analysis of cortical bone using laser ultrasound techniques

The application of bone quality assessment has received extensive attention, and a large number of researchers continue to invest in related research activities. To get closer to the real situation, this study intends to investigate the long bones of cattle. A quantitative laser ultrasound visualization (QLUV) system was used to measure the images transmitted by the guided waves on the long bones, and the internal defects of the long bones were detected using wave propagation behavior. Then, linear scanning was performed through a laser ultrasound technique (LUT) to measure the dispersion curve of the cortical bone, and the results were compared with finite element simulations. Further, LUT was used to measure the material properties of the cortical bone in all directions. Finally, the long bones were scanned by computerized tomography to analyze the pore direction and distribution. Further, the relationship between pore direction and material properties was studied. The results showed that the obtained wave propagation image was consistent with the time-domain waveform signal and the finite element analysis results. The experimental and simulation results of wave velocity showed an error of 0.26 to 1.56% compared with the literature. The plate-shaped cortical bone showed that the phase velocity of the guided wave is higher than the circumferential direction. The defect location was identified through wave propagation behavior using the QLUV system. The elastic constant of the cortical bone was measured, and it showed the same trend as the results obtained from the tensile test in the literature. Also, the pore distribution indicated that the cortical bone porosity has the same trend as elastic constants. The elastic constants along the longitudinal direction were greater than the transversal direction. This laser ultrasound technique has been developed with an aim of having a better resolution and also as a potential application in osteoporosis conditions.