Vibro-acoustic analysis of the acoustic-structure interaction of flexible structure due to acoustic excitation $ Harijono Djojodihardjo a,b a Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia b Faculty of Engineering, Universitas Al-Azhar Indonesia, Jalan Sisingamangaraja, Jakarta 121010, Indonesia article info Article history: Received 8 December 2013 Received in revised form 15 October 2014 Accepted 16 November 2014 Available online 18 December 2014 Keywords: Acoustic-structure interaction BEM–FEM coupling Boundary element method Vibro-acoustics abstract The application of BE–FE acoustic-structure interaction on a structure subject to acoustic load is elaborated using the boundary element–finite element acoustic structural coupling and the utilization of the computational scheme developed earlier. The plausibility of the numerical treatment is investigated and validated through application to generic cases. The analysis carried out in the work is intended to serve as a baseline in the analysis of acoustic structure interaction for lightweight structures. Results obtained thus far exhibit the robustness of the method developed. & 2014 IAA. Published by Elsevier Ltd. All rights reserved. 1. Introduction During flight missions, space vehicles, such as illustrated in Fig. 1 [1], are subjected to a severe dynamic pressure load- ing and broadband, aeroacoustic and structure-borne excita- tions of various circumstances, which can endanger the survivability of the payload and the vehicles electronic equ- ipment, and consequently the success of the mission. Aero- space structures are generally characterized by the use of exotic composite materials of various configurations and thi- cknesses, as well as by their extensively complex geometries and connections between different subsystems. It is there- fore of crucial importance for the modern aerospace indus- try, the development of analytical and numerical tools that can accurately predict the vibroacoustic response of large, composite structures of various geometries and subject to a combination of aeroacoustic excitations. Assisted with computing capability and user-friendly computer-aided analysis software, the analyst is challenged to ensure that the analysis includes all the relevant physical phenomena. Simple fundamental principles are mandatory, in order not to lose insight into the interrelationships bet- ween relevant elements, and to devise simple methods that are robust to address various problems. Space borne struc- ture must be able to resist the loads induced by the launch environment, and meet all the functional performances required on orbit such as dimensional stability and struc- tural integrity. Noise and vibration should also be taken as critical consideration in the design of aerospace vehicles for fatigue of components arising from interior structural and acoustic pressure fluctuations due to external structural or acoustic loading [2–9]. Other related works are reported in references [10–13]. Pappa et al. [10–12] summarize modal testing activities at the NASA Langley Research Center for generic aircraft fuselage structures. Citarella et al. [13] set up an integrated approach for an automobile vibro-acoustic analysis to assess, visualize and compare vibro-acoustic per- formance to pre-determined design targets and identify and quantify the forces and sound sources responsible for their prevailing behavior. The great number of design variables allows us to syner- gistically fulfill high stiffness and acoustic standards. Hence the objective of the present paper is to describe the applica- tion of BE–FE fluid structure interaction on a structure subject Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/actaastro Acta Astronautica http://dx.doi.org/10.1016/j.actaastro.2014.11.026 0094-5765/& 2014 IAA. Published by Elsevier Ltd. All rights reserved. ☆ This paper was presented during the 64th IAC in Beijing. E-mail address: harijono@djojodihardjo.com Acta Astronautica 108 (2015) 129–145