A vibration-based sound power (VBSP) measurement method is appealing because of its potential versatility in application compared to pressure- and intensity-based methods. The VBSP method is based on the well-known elementary radiators approach and is reliant on the acoustic radiation resistance matrix. Previous research has developed and validated the VBSP method for flat plates and cylinders. This thesis details work on extending the VBSP method to arbitrarily-curved structures. The approach of computing surface normal velocities from 3D velocity data measured by a scanning laser Doppler vibrometer (SLDV) is presented. This approach is validated with experimental sound power results of a cylindrical shell using the VBSP method with 3D velocity and geometry data. The sound power results are shown to have good agreement with ISO 3741 results. Experimental sound power results from three simple-curved plates using the VBSP and ISO 3741 methods are shown to have good agreement. These experimental results indicate that the VBSP method is less sensitive to background noise than the ISO 3741 method. An overview of exploring inherent symmetry in the radiation resistance matrix is presented for the purpose of increasing efficiency in applying the VBSP method. Sound power sensitivity to the formulation of the radiation resistance matrix is explored as another relevant option for increasing the efficiency of the VBSP method for many cases and for extending the method to more complex structures. The results of the radiation resistance matrix exploration enable the VBSP method to apply to arbitrarily-curved structures. Experimental sound power results using the VBSP method with the simple-curved plate radiation resistance matrix and the ISO 3741 method are compared for two arbitrarily-curved panels and are shown to have good agreement. The VBSP method based on the simple-curved plate form of the radiation resistance matrix is shown to have excellent agreement with numerical results from boundary element models, which inherently use the appropriate form of the radiation resistance matrix.

The International Organization for Standardization (ISO) provides no vibration-based sound power measurement standard that provides Precision (Grade 1) results. Current standards that provide Precision (Grade 1) results require known acoustic environments or complex setups. This thesis details the Vibration Based Radiation Mode (VBRM) method as one approach that could potentially be used to develop a Precision (Grade 1) standard. The VBRM method uses measured surface velocities of a structure and combines them with the radiation resistance matrix to calculate sound power. In this thesis the VBRM method is used to measure the sound power of a single-plate and multiple plate system. The results are compared to sound power measurements using ISO 3741 and good alignment between the 200 Hz and 4 kHz one-third octave band is shown. It also shows that in the case of two plates separated by a distance and driven with uncorrelated sources, the contribution to sound power of each individual plate can be calculated while they are simultaneously excited. The VBRM method is then extended to account for acoustically radiating cylindrical geometries. The mathematical formulations of the radiation resistance matrix and the accompanying acoustic radiation modes of a baffled cylinder are developed. Numberical sound power calculations using the VBRM method and a boundary element method (BEM) are compared and show good alignment. Experimental surface velocity measurements of a cylinder are taken using a scanning laser Doppler vibrometer (SLDV) and the VBRM method is used to calculate the sound power of a cylinder experimentally. The results are compared to sound power measurements taken using ISO 3741.