Institute of Acoustics,Nanjing University,Nanjing 210093,China;
Institute of Acoustics,Nanjing University,Nanjing 210093,China;
Institute of Acoustics,Nanjing University,Nanjing 210093,China;
Institute of Acoustics,Nanjing University,Nanjing 210093,China;
composite material; inversion of elastic constants; wavelet transform; neural networks;