Abstract
In this paper experimental and numerical results concerning the dynamic response of composite sandwich beams with curvature and debonds are reported. Sandwich beams made of carbon/epoxy face sheets and polyurethane foam core material were manufactured with four different radii of curvature and debonds between the top and bottom interface of face sheet and foam core. Dynamic response was obtained using the impulse frequency response technique under clamped-clamped boundary condition. Experimental results were compared with numerical finite element model results. A combined experimental and numerical FE approach was used to determine the material properties of the skin and foam core materials based on modal vibration and static flexure tests. Results indicate that the fundamental frequency increases with increasing curvature angle, however, for higher frequencies; the natural frequencies are not significantly affected. Also, it is found that face/core debond causes reduction of the natural frequencies due to stiffness degradation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Zenkert D (1995) Introduction to sandwich construction. Chameleon Press, London
Petyt M, Fleischer CC (1971) Free vibration of a curved beam. J Sound Vib 18:17–30
Rossettos JN, Perl E (1978) On the damped vibratory response of curved viscoelastic beams. J Sound Vib 58:535–544
Tüfekci E, Arpaci A (1998) Exact solution of in-plane vibrations of circular arches with account taken of axial extension, transverse shear and rotatory inertia effects. J Sound Vib 209(5):845–856
Öz HR, Pakdemirli M, Özkaya E, Yilmaz M (1998) Non-linear vibrations of a slightly curved beam resting on a non-linear elastic foundation. J Sound Vib 212(2):295–309
Ahmed KM (1971) Free vibration of a curved sandwich beam by the finite element method. J Sound Vib 18:61–74
Noor AK, Burton S (1998) Computational models for sandwich panels and shells. Appl Mech Rev 49(3):155–159
Sakiyama T, Matsuda H, Morita C (1997) Free vibration analysis of sandwich arches with elastic or viscoelastic core and various kinds of axis-shape and boundary conditions. J Sound Vib 203(3):505–522
Vaswani J, Asnani NT, Nakra BC (1998) Vibration and damping analysis of curved sandwich beams with a elastic core. Compos Struct 10(3):231–245
Kwon O (2007) Dynamic characteristics of cylindrical hybrid panels containing viscoelastic layer based on layerwise mechanics. Compos B Eng 38:59–171
Shipsha A, Hallstrom S, Zenkert D (2003) Failure mechanisms and modeling of impact damage in sandwich beams-a 2D approach: part I: experimental investigation. J Sandw Struct Mater 5:7–31
Kim WC, Miller TC, Dharon CKH (1993) Strength of composite sandwich panels containing debonds. Int J Solids Struct 30:211–223
Vadakke V, Carlsson LA (2004) Experimental investigation of compression failure of sandwich specimens with face/core debond. Compos B Eng 35:583–590
Kim HY, Hwang W (2002) Effect of debonding on natural frequencies and frequency response functions of honeycomb sandwich beams. Compos Struct 55(1):51–62
Li Z, Crocker MJ (2006) Effect of thickness and delamination on the damping in honeycomb-foam sandwich beams. J Sound Vib 294:473–485
Lee J (2000) Free vibration analysis of delaminated composite beams. J Sound Vib 301:252–277
Salawu OS (1996) Detection of structural damage through changes in frequency: a review. Eng Struct 19(9):718–723
Gibson RF (2000) Modal vibration response measurements for characterization of composite materials and structures. Compos Sci Technol 60:2769–2780
Yan YJ, Chang L, Wu ZY, Yan LH (2007) Development in vibration-based structural damage detection technique. Mech Syst Signal Process 21:2198–2211
Lee YS, Chung MJ (2000) A study on crack detection using eigen frequency test data. Comput Struct 77(3):327–342
Rossettos JN (1998) Effects of a delamination and initial curvature on the fundamental frequency of sandwich beams. J Sound Vib 210(1):153–161
Hoff NJ (1956) The analysis of structures. Wiley, New York
Majundar P, Srinivasagupta D, Mahfuz H, Joseph B, Thomas MM, Christensen S (2003) Effect of processing conditions and material properties on the debond fracture toughness of foam-core sandwich composites: experimental optimization. Compos Part A-Appl Sci Manufact 34(11):1097–1104
Srinivasagupta D, Joseph B, Majundar P, Mahfuz H (2003) Effect of processing conditions and material properties on the debond fracture toughness of foam-core sandwich composites: process model development. Compos Part A-Appl Sci Manufact 34(11):1085–1095
Aviles F, Carlsson LA (2007) Post-buckling and debond propagation in sandwich panels subject to in-plane compression. Eng Fract Mech 74:794–806
Frostig Y, Thomsen OT (2005) Non-linear behavior of delaminated unidirectional sandwich panels with partial contact and a transversely flexible core. Int J Non-linear Mech 40:633–651
Givli HS, Robinovitch O, Frostig V (2007) Free vibrations of delaminated unidirectional sandwich panels with a transversely flexible core-a modified Galerkin approach. J Sound Vib 301:253–277
Tsai SW, Hahn HT (1980) Introduction to composite materials. Technomic Publishing Co, Lancaster
Acknowledgment
This work was sponsored by TUBITAK (The Scientific and Technological Research Council of TURKEY) under the project “Effects of a delamination/debond and curvature on the vibration response of sandwich composites” numbered 107 M615.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Baba, B., Thoppul, S. & Gibson, R. Experimental and Numerical Investigation of Free Vibrations of Composite Sandwich Beams with Curvature and Debonds. Exp Mech 51, 857–868 (2011). https://doi.org/10.1007/s11340-010-9388-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11340-010-9388-5