Application and Study on Preconditioned Conjugate Gradient Method Algorithm in Concrete Ultrasonic Computerized Tomography

The structural characteristic is given by computerized tomography in non-destructive testing (NDT) of concrete. The position, size and style of inner defects can be shown. A Preconditioned Conjugate Gradient Method (PCG) from a view of probability for concrete image reconstruction is presented in this paper. In PCG, we present a class of conjugate gradient methods with a new conjugacy condition M which is proved under suitable conditions. The M combined with a general Conjugate Gradient Method, which lead to Preconditioned Conjugate Gradient Method (PCG). Computer simulation and concrete model of ultrasonic computerized tomography show that the PCG is more effective to improve the accuracy of computation and the quality of image reconstruction on concrete than the Conjugate Gradient Method (CG).