Waves transmission through plate and beam junctions

The evaluation of wave transmission in structural junctions is an important part of the study of structure-borne noise. In this paper, a method for ca lculating the wave transmission through plate and beam junctions is describ ed. It is assumed that the joint element is an elastic block. Linear approx imation of the displacement field is introduced to derive equations which d escribe the dynamic response of the joint element. A numerical example is p resented to illustrate the method. The example involves the analysis of vib ratory power transmission through T-junction of three plates. Wave transmis sion theory is used to find the complex-wave amplitudes for transmitted and reflected waves. The complex-wave amplitudes are used to calculate the tra nsmission efficiencies. This example also includes a comparison of the pres ented method with other methods for evaluating the wave transmission throug h junctions. Results of calculations show that the effect of three-dimensio nal deformation of a junction is important in the mid- and high-frequency r ange. (C) 1999 Elsevier Science Ltd. All rights reserved.