中文摘要：

金属材料在各个领域的应用日趋广泛，但是其内部缺陷常会导致产品不能正常使用，甚至引起重大的安全隐患，因此对构件内部缺陷检测并识别日趋重要。本文同日寸采用有限元和实验两种手段对均匀介质中的缺陷检测进行研究。首先，以中心圆孔为内部缺陷的铝圆柱体作为研究对象，采用探头垂直人射的水浸式超声检测方法进行研究，通过实验获得缺陷回波信号。其次，为对比实验检测结果，引八有限元分析软件ANSYS，对声波传播进行仿真计算并获得缺陷回波信号。对所获得的缺陷回波信号进行频域处理，对比实验及有限元两种方法所获得的频谱图。结果表明，有限元仿真结果与实验结果基本一致，可从缺陷回波信号的频谱图看出缺陷的形状以及大小不一样。

英文摘要：

Metal materials are applied in various application fields more and more widely. But their internal defects always lead to the improper use of products and even cause great potential safety hazard. Therefore the detection of component defects has become important increasingly.The detection of defects in homogeneous materials is researched with the Finite Element Method（FEM） and the experiments in this paper. First, with an aluminum alloy cylinder with the internal defect of a center hole as the research object, water-immersion ultrasonic testing method with the perpendicular incident probe is adopted and the echo signals of the defect are got. In order to get the contrast with the experiment results, FEM software ANSYS is introduced to simulate the ultrasonic paths and get echo signals of the defect too. Then the obtained time domain signals from FEM and experiments are transformed into frequency domain signals by Fourier transformation respectively, and the spectrums are contrasted. The results show that the simulation results from FEM are identical with the experiment results basically. And the shape and size of the defect can be known from the spectrum of its echo signals.