A finite element/boundary element design tool is used to perform a structural acoustic optimization on an eight-ply graphite epoxy cylindrical shell. The shell is subject to two external monopole sources vibrating at a single frequency. The goal of the optimization is the minimization of the sum of the squared pressure amplitudes within the enclosed acoustic cavity. The ply angles serve as the design variables in optimization. The optimal design was obtained after 15 iterations with a 2 dB reduction in the average interior sound pressure level. The ply angle orientation shifted from an initially symmetric lay-up to an unsymmetric lay-up in the final design.

1.
Engelstad, S. P., et al., 1997, Optimization in Structural Acoustics Using FEM/BEM, Report No. NAS1-20102, NASA Langley Research Center, Hampton, VA.
2.
Fernholz, C. M., and Robinson, J. H. 1996, The Influence of Lamination Angles on Interior Noise Level of an Aircraft, Report No. NASA TM-110250, NASA Langley Research Center, Hampton, VA.
3.
Walden, D. C., 1990, “Applications of Composites in Commercial Airplanes,” Proceedings of the Annual ASM/ESD Advanced Composites Conference, p. 77.
4.
Abrate
,
S.
,
1994
, “
Optimal Design of Laminated Plates and Shells
,”
Compos. Struct.
,
29
(
3
), p.
269
286
.
5.
Lamancusa
,
J. S.
,
1993
, “
Numerical Optimization Techniques for Structural-Acoustic Design of Rectangular Panels
,”
Comput. Struct.
,
48
(
4
), pp.
661
675
.
6.
Engelstad, S. P., et al., 1995, “Optimization Strategies for Minimum Interior Nose and Weight using FEM/BEM,” 1995 International Conference on Noise Control Engineering, Newport Beach, CA.
7.
Yang
,
T. C.
, and
Tseng
,
C. H.
,
1993
, “
Integrating and Automating Analysis and Optimization
,”
Comput. Struct.
,
48
(
6
), pp.
1083
1106
.
8.
Maksimovic
,
S.
,
1990
, “
Some Computational and Experimental Aspects of Optimal Design Process of Composite
,”
Compos. Struct.
,
17
, pp.
237
258
.
9.
Lahey, R. S., Miller, M. P., and Reymond, M., 1995, MSC/NASTRAN Version 68 Reference Manual, Los Angeles, MacNeal-Schwendler Corporation.
10.
Automated Analysis Corporation, 1995, COMET/Acoustics User Document, Automated Analysis Corporation, Ann Arbor, MI.
11.
Crane
,
S.
, et al.
,
1996
, “
A Comparison of Optimization Formulations for Design Minimization of Aircraft Interior Noise
,”
AIAA J.
,
34
(
2
), pp.
236
2434
.
You do not currently have access to this content.