Modeling and optimization of floating raft systems in submarines under different objectives by using hybrid genetic algorithm

Abstract

A systematic modeling and optimization method for analyzing typical floating raft systems in submarines is presented and optimization under different vibro-acoustic objectives is investigated. The Frequency Response Function-based (FRF-based) substructuring method and the coupled Finite Element/Boundary Element (FE/BE) method are employed to study vibration transmission from the vibrating machinery to the base structure as well as the vibro-acoustic behavior of the fluid- loaded cylindrical structure. The hybrid genetic algorithm (HGA) involving the FRF-based substructuring sensitivity analysis (SA) and the genetic algorithm (GA) is developed and applied to obtain the optimal values of stiffness of isolators under five objective functions at low frequencies. Optimization is carried out for two cases where the fluid–structure interaction is considered and neglected respectively. The modeling results demonstrate that the effect of fluid-loading reduces the driving point mobility of the connecting points on the base structure but has little influence on the isolation frequencies of the whole floating raft system. The optimized results are compared with those obtained by SA and GA. The results of SA show a regular trend of variation while those of GA show an irregular trend. Since GA is a stochastic optimization technique, the trend of variation in the results of HGA combines those of GA and SA. The optimized results demonstrate that HGA possesses the merits of SA and GA, and never gets trapped at a local optimum or goes into premature convergence. Compared with SA and GA, however, it requires more evaluation of objective functions in each iteration step and as a result is not computationally efficient.

Keywords

Coupled FE/BE FRF-based substructuring method genetic algorithm hybrid genetic algorithm sensitivity analysis

Get full access to this article

View all access options for this article.

References

Alkhatib

Nakhaie Jazar

Golnaraghi

(2004) Optimal design of passive linear suspension using genetic algorithm. Journal of Sound and Vibration 275(3-5): 665–691.

Chang

Park

(1998) Substructure dynamic modification using component receptance sensitivity. Mechanical Systems and Signal Processing 12(4): 525–541.

Choi

Xiong

Shenoi

(2009) Power flow analysis for a floating sandwich raft isolation system using a higher-order theory. Journal of Sound and Vibration 319(1–2): 228–246.

Els

Uys

Snyman

(2006) Gradient-based approximation methods applied to the optimal design of vehicle suspension systems using computational models with severe inherent noise. Mathematical and Computer Modelling 43(7–8): 787–801.

Everstine

Henderson

(1990) Coupled finite element/boundary element approach for fluid-structure interaction. Journal of the Acoustical Society of America 87(5): 1938–1947.

Foumani

Khajepour

Durali

(2003) Optimization of engine mount characteristics using experimental/numerical analysis. Journal of Vibration and Control 9(10): 1121–1121.

Goldberg

(1989) Genetic Algorithms in Search and Optimization New York: Addison-Wesley.

Gundogdu

(2007) Optimal seat and suspension design for a quarter car with driver model using genetic algorithms. International Journal of Industrial Ergonomics 37(4): 327–332.

McPhee

(2005) A design methodology for mechatronic vehicles: application of multidisciplinary optimization, multibody dynamics and genetic algorithms. Vehicle System Dynamics 43(10): 697–733.

10.

Holmstrom

. Practical optimization with the TOMLAB environment in Matlab. Proceedings of the 42nd SIMS Conference, (2001) Telemark University College, Porsgrunn, Norway, 89–108. October, 2001.

11.

Laulagnet

Guyader

(1989) Modal analysis of a shell’s acoustic radiation in light and heavy fluids. Journal of Sound and Vibration 131(3): 397–415.

12.

Laulagnet

Guyader

(1990) Sound radiation by finite cylindrical ring stiffened shells. Journal of Sound and Vibration 138(2): 173–191.

13.

Lee

D-H

Hwang

W-S

(2003) Parametric optimization of complex systems using a multi-domain FRF-based substructuring method. Computers & Structures 81(22–23): 2249–2257.

14.

Lee

Hwang

Kim

(2002) Design sensitivity analysis and optimization of an engine mount system using an FRF-based substructuring method. Journal of Sound and Vibration 255(2): 383–398.

15.

(2001) Experimental Modal Analysis And Application Beijing: Science Press.

16.

Zhang

Zuo

(1997) Structural power flow analysis for a floating raft isolation system consisting of constrained damped beams. Journal of Sound and Vibration 202(1): 47–54.

17.

Lavrich

(1999) Prediction of power flows through machine vibration isolators. Journal of Sound and Vibration 224(4): 757–774.

18.

Liu

Chen

(2009) Numerical analysis of immersed finite cylindrical shells using a coupled BEM/FEM and spatial spectrum approach. Applied Acoustics 70(2): 256–266.

19.

Liu

Ewins

(2002) Substructure synthesis via elastic media. Journal of Sound and Vibration 257(2): 361–379.

20.

Niu

Song

Lim

(2005) On active vibration isolation of floating raft system. Journal of Sound and Vibration 285(1–2): 391–406.

21.

Shirahatti

Prasad

Panzade

(2008) Optimal design of passenger car suspension for ride and road holding. Journal of the Brazilian Society of Mechanical Sciences and Engineering 30: 66–76.

22.

Singh

Kim

(2003) Examination of multi-dimensional vibration isolation measures and their correlation to sound radiation over a broad frequency range. Journal of Sound and Vibration 262(3): 419–455.

23.

Swanson

Ashrafiuon

(1993) Optimization of aircraft engine suspension systems. Journal of Aircraft 30(6): 979–984.

24.

Tao

Liu

Lam

(2000) Design optimization of marine engine-mount system. Journal of Sound and Vibration 235(3): 477–494.

25.

Thoresson

Uys

Els

(2009a) Efficient optimisation of a vehicle suspension system, using a gradient-based approximation method, Part 1: Mathematical modelling. Mathematical and Computer Modelling 50(9–10): 1421–1436.

26.

Thoresson

Uys

Els

(2009b) Efficient optimisation of a vehicle suspension system, using a gradient-based approximation method, Part 2: Optimisation results. Mathematical and Computer Modelling 50(9–10): 1437–1447.

27.

Xie

Chan

(2007) Design optimization of machinery mounting systems with an elastic support structure. Engineering Optimization 39(2): 229–244.

28.

Xie

Chan

(2008) Design optimization of vibration isolation system through minimization of vibration power flow. Structural Engineering and Mechanics 28(6): 677–694.

29.

Xiong

Xing

Price

(2001) Power flow analysis of complex coupled systems by progressive approaches. Journal of Sound and Vibration 239(2): 275–295.

30.

Shen

Hua

(2002) Coupling vibro-acoustic behavior from a submarine power cabin equipped with floating-raft isolating systems. Electronic Journal Technical Acoustics 2(11): 1–10.