Energy finite element analysis of naval vehicles.

Abstract

Simulation methods can be used for meeting both the new acoustics and vibration initiatives for surface ship silencing. An energy finite element analysis (EFEA) formulation has been developed for computing efficiently the vibration of complex structures and the associated radiated noise at frequencies beyond the limits of conventional finite element methods. The EFEA provides a very attractive alternative to the statistical energy analysis (SEA) because it uses the same finite element model which is utilized for other simulations (i.e., structural analysis), while the SEA requires the development of a completely new model based on a lumped parameter approach. Further, the SEA requires estimates of modal densities for the various subsystems which introduce difficulties and approximations in the solution. Thus, the EFEA streamlines the structural-acoustic analysis within the ship design process due to modeling commonality with other disciplines. In this presentation, the main theoretical aspects of the EFEA will be presented first. Results presented for two 1/8th scale structures representing an advanced double hull design and a conventional hull design of a surface ship are analyzed. Results for the structural vibration induced on the outer bottom part of the structures are compared to available test data.

Research status and development trend of energy finite element analysis: a review

“…In 1996, Bitsie [50] used the EFEA to analyze the plate-acoustic coupling structure. From 2005 to 2010, Zhang W. G. and Raveendra S. T. [51][52][53][54][55] and others conducted a series of analyses of the acoustic-vibration coupling structure using EFEA. They analyzed the ship structure with both structural elements and acoustic space by using EFEA.…”

“…In 2008, Sun L. P. and Nie W. [3] conducted related research on the simplified structure of a frigate's base using EFEA. From 2005 to 2010, Zhang W. G. and Raveendra S. T. et al [51][52][53][54][55] used the EFEA to conduct a series of acoustic-vibration coupling analyses on the ship structure with both acoustic space and structural elements. In 2008, Wu Y. G. [84] researched EFEA0 and studied the application of EFEA0 to ship acoustic-vibration coupling and radiation noise.…”

“…In 2009, Wang A. M. et al [117] combined EBEA and EFEA methods to predict the noise level inside a vehicle due to external sound sources and provided a complete EBEA/EFEA simulation process for airborne vehicle simulation. From 2005 to 2007, Hong M. N. and others [55][56][57] used the EFEA to analyze the acoustic and vibration characteristics of vehicles. In 2018, Lin Z. L. [2] studied the energy density of thin plates and their coupled structures.…”

Prediction of the Transient Local Energy by Energy Finite Element Analysis

“…Suppose there are i beams that are linked at a joint (Figure 1). The force acting on the cross-section can be written in the form of Equation (38):…”

“…External factors, such as thermal loads [31] and external forces [32], have also been considered. EFEA has also been validated by applying it to some complex structures, such as aircraft [33][34][35], ships [27,36], and vehicles [37][38][39]. Although EFEA has been successfully used, few studies have been conducted on transient analysis based on EFEA.…”