Two dimensional image reconstruction of log cross-section defect based on stress wave technique

摘要

Wood is a material that is produced biologically in the growing tree, making it vulnerable to the attack of fungi. This will reduce the quality of wood, especially for log. The 2D image reconstruction contributed greatly for log cross-section defect testing in order to promote the utilization rate of wood resources. At first, this paper studied the stress wave computerized tomography technique, and introduced the straight-line tracing technique and the Algebraic Reconstruction Technique (ART) algorithm. Then, the medium model was constructed for numerical simulation analysis. The reconstruction of the medium model was conducted using straight line tracing — ART algorithm, and the impact of the number of iterations for image reconstruction accuracy was analyzed. At last, this paper validated the feasibility for two-dimensional image reconstruction of log internal defects using this method by physical model testing. Empirical and medium model results showed that the convergence of straight line tracing — ART algorithm was fast and reconstruction image was good. The two-dimensional image reconstruction of log internal defects could basically be realized using the straight line tracing-algebraic reconstruction algorithm method. And the feasibility and practicality of theory and technique that proposed in this paper were validated by practical testing.