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Abstract

Recent work has shown that damped composite structures can be fabricated successfully by co-curing embedded damping layers in carbon/epoxy prepreg laminates using autoclave processing. However, no attention has been given to embedding damping layers into composite structures using low-cost fabrication methods such as the vacuum assisted resin transfer molding (VARTM) process. The current research presented in this article outlines a unique method of embedding impermeable damping layers into low-cost composite plates fabricated using the VARTM process. The damping layers are perforated with a series of small holes to allow the resin to flow through the damping layer and completely wet-out the plate. Experimental vibration and stiffness testing are performed to investigate the effect of perforation hole diameter and hole spacing on the damped structural behavior. Results show that the damping and stiffness can be very sensitive to perforation spacing, size, and location. It is shown that for small diameter moderately spaced perforations (99.7% damping area or greater) the damping increased by a factor of 14.3 over undamped plates, whereas slightly increasing the hole diameter or decreasing the spacing (95% damping area) resulted in significantly lower damping performance (2.2 factor increase over the undamped plate). For displacement critical vibration suppression, it was shown that plates with perforated damping layers will out-perform fully damped plates. Experimental and finite element results as well as practical design considerations for fabricating damped composite structures using the VARTM process are presented.

Keywords

composites damping vibration control VARTM RTM embedding fabrication manufacturing

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References

Ross, D. , Ungar, E.E. and Kerwin, Jr., E.M. (1959). Damping of Flexural Vibrations by means of Viscoelastic Laminae, Section III, Structural Damping ASME, New York .

Finegan, I.C. and Gibson, R.F. (1999). Recent Research on Enhancement of Damping in Polymer Composites , Composite Structures, 44(2,3): 89–98 .

Rao, M.D. and He, S. (1993). Dynamic Analysis and Design of Laminated Composite Beams with Multiple Damping Layers , AIAA Journal, 31(4): 736–745 .

Napolitano, K.L. and Kosmatka, J.B. (1998). Comparison of Two Co-cured Damped Composite Torsion Shafts , Composite Structures, 43(2): 115–125 .

Napolitano, K.L. and Kosmatka, J.B. (1998). Co-cured Extension-Twist Coupled Damped Composite Strut , Journal of Composite Materials, 32(21): 1914–1932 .

Trego, A. and Eastman, P. (1999). Flexural Damping Predictions of Mechanical Elements Using Stress Coupled, Co-cured Damped Fiber Reinforced Composites , Journal of Advanced Materials, 31(1): 7–17 .

Kosmatka, J.B. and Mehmed, O. (2002). Development of an Integral Damping Treatment for NASA's Next Generation Hollow Fan Blades , In: Proceedings of SPIE Smart Structures and Materials, Vol. 4697, pp. 15–24 .

Ma, Z. (2004). Integrally Damped Efficient Low Noise Composite Fan Blades, Masters Thesis, University of California, San Diego.

Biggerstaff, J.M. and Kosmatka, J.B. (1999). Shear Measurements of Viscoelastic Damping Materials Embedded in Composite Plates , In: Proceeding of SPIE Smart Structures and Materials, Vol. 3672, pp. 82–92 .

10.

Biggerstaff, J.M. and Kosmatka, J.B. (1998). Damping Performance of Co-cured Graphite/Epoxy Composite Laminates with Embedded Damping Materials , Journal of Composite Materials, 33(15): 1457–1469 .

11.

Sayre, J.R. and Loos, A.C. (2004). Resin Infusion of Triaxially Braided Preforms with Through the Thickness Reinforcement , Polymer Composites, 24(2): 229–236 .

12.

Shih, C. , Liu, Q. and Lee, L.J. (2004). Vacuum-Assisted Resin Transfer Molding Using Tackified Fiber Preforms , Polymer Composites, 22(6): 721–729 .

13.

Seemann, W.H. (1990). US Pat. 4,902,215.

14.

Robinson, M.J. and Kosmatka, J.B. (2005). Low-Cost VARTM Processing of Thin Laminate Composites with Embedded Impervious Layers , In: Proceedings of SAMPE 2005: New Horizons for Materials and Processing Technologies, May 1–5, 2005, Long Beach, CA [cd-rom], 14 pages.

15.

LMS CADA-X Modal Analysis Manual, Revision 3.4, 1996 LMS International, 3-33—3—36.

Improved Damping in VARTM Composite Structures using Perforated Viscoelastic Layers

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