electromagnetic wave theory was used by ground penetrating radar, the defects in concrete dams were judged according to the measured concrete reflection waveform, frequency and wave velocity. The working principle of ground penetrating radar and numerical simulation process based on the finite different time domain method were studied, cracks, voids images in concrete was forward simulated by the above method. It was important to determine the quality defects in concrete.

This paper introduces a computer-aided concurrent tolerance design system based on real manufacturing resources (CATFM), which can ensure the optimal robust tolerance and consider real manufacturing resource owned by the factory. Firstly, the concurrent tolerance design model which can get balance between quality and cost utilizing Taguchi's quality loss function is proposed. Then the principle of concurrent tolerancing is concisely depicted through analyzing the overall structure of the system, and the design method is described in detail. Finally, an example is adopted to illustrate the proposed system.