Abstract:
The prediction and computation of the vibration structural intensity have been accomplished for simple structures, such as beams, rods, plates, and shells. These structures, even when connected to other simple structures, were amenable to analytic solutions, which allowed the researchers to obtain exact analytic expressions for the power flow and the structural intensity vector maps for these structures. A calculation of the structural intensity by the use of finite-element methods (FEM) is proposed. This hybrid method requires that one must delve into the FEM codes to retrieve all the resultant moments, shears, normal forces, as well as the transverse, tangential, and rotational velocities. These quantities are processed to result in complete structural intensity maps. The influence of mesh size, the use of resultants at the mid of the elements, and mesh size requirements as a function of axial, flexural, and torsional wavelengths are explored. An example of a connected branched structure undergoing coupled flexural, longitudinal, and torsional vibration is analyzed to illustrate the influence of these parameters on the accuracy of the structural intensity calculations.