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.

This dissertation advances the Vibration-Based Sound Power (VBSP) method for measuring the sound power of vibrating structures, expanding its applicability to a wider range of geometries and acoustic environments. The research addresses limitations of traditional sound power measurement techniques by developing an alternative method that achieves near Precision (Grade 1) accuracy while maintaining feasibility for in situ testing under uncontrolled acoustic conditions. After reviewing the current VBSP method in Unit 1, Unit 2 introduces stitching techniques for Scanning Laser Doppler Vibrometer (SLDV) measurements, enabling accurate 3D scans and extending the method to complex geometries. Experimental validation is provided for baffled simply curved plates and arbitrarily curved plates. The method also estimates sound power in uncontrolled acoustic environments, where traditional approaches are less effective. Initial work on thin unbaffled flat plates is presented, with a practical demonstration using pickleball paddles as a representative unbaffled configuration. Unit 3 addresses the computational demand of constructing radiation resistance (R) matrices, a key limitation of the VBSP method. Symmetry-based techniques leveraging acoustic reciprocity and geometric symmetries are applied to reduce computational demands by up to 75% for unbaffled structures. For baffled configurations, translational symmetry of acoustic reciprocity between elements results in the R matrix having Toeplitz symmetry, reducing the computational complexity from n^2 to n, where n is the number of mesh elements. Unit 4 introduces an indirect VBSP (I-VBSP) method to estimate sound power from encased sources, achieving near Precision (Grade 1) accuracy relative to the ISO 3741 standard using only a single surface scan. Validated on a Bluetooth speaker, this approach provides a simplified alternative to conventional methods, offering a practical solution for sound power measurement in structures with encased noise sources. Overall, this dissertation demonstrates that the VBSP method serves as a viable alternative to conventional sound power techniques, effectively applied across various geometries and scenarios. While the current VBSP method does not accommodate structures with multiple vibrating surfaces in contact, the I-VBSP method can theoretically achieve this by enclosing a structure and scanning one vibrating side. This research lays the foundation for future studies through the development of a generalized R matrix and application of foundational symmetries, enhancing the understanding of acoustic radiation from vibrating structures. Ultimately, this work aims to reduce noise pollution in consumer products through improved acoustic design and measurement strategies.