This research combines theoretical and experimental approaches for dynamic material characterization of composite materials. The samples studied include continuous fiber graphite/epoxy beams with various symmetric lay-up configurations. Included are laminated beams with the following lay-ups: [08/908]s, [908/08]s, [(45/0/−45)5]s and [(0/45/0/−45)3/90/0/01/2]s. The resonant dwell technique is used to determine the material damping and the real part of the dynamic flexural modulus of double cantilever beam specimens in the first mode of vibration over the frequency range 25 Hz to 300 Hz. The dynamic properties are determined as a function of the frequency of oscillation at room temperature. In addition, the Metravib Viscoanalyzer, based on off-resonance tests, is also used to provide another source of experimental data for comparison. Although the Viscoanalyzer was originally intended for testing viscoelastic polymers, the present research establishes the limits of applicability for composite materials, with particular emphasis on the three point bending test. Comparisons and limitations of both techniques are critically discussed.

Issue Section:
Technical Papers
Topics:
Composite materials, Resonance, Cantilever beams, Damping, Elastomers, Epoxy adhesives, Epoxy resins, Experimental methods, Fibers, Graphite, Oscillations, Temperature, Testing, Vibration
1.
Adams, R. D., 1987, “Damping Properties Analysis of Composite Materials: Analysis and Design,” J. of Composite Materials, Mar., pp. 206–217.
2.
ASTM D4065
,
1990
, “
Standard Practice for Determining and Reporting Dynamic Mechanical Properties of Plastics
,”
ASTM Standards
, Vol.
08.01
, pp.
320
–
324
.
3.
ASTM D5023
,
1990
, “
Standard Method for Measuring the Dynamic Mechanical Properties of Plastics Using Three Point Bending
,”
ASTM Standards
, Vol.
08.02
, pp.
711
–
713
.
4.
ASTM D5024
,
1991
, “
Standard Test for Measuring the Dynamic Mechanical Properties of Plastics in Compression
,”
ASTM Standards
, Vol.
08.02
, pp.
714
–
716
.
5.
Bert
 
C. W.
,
1973
, “
Material Damping: An Introductory Review of Mathematical Models, Measures and Experimental Techniques
,”
J. of Sound and Vibration
, Vol.
29
, No.
2
, pp.
129
–
153
.
6.
Blevins, R. D., 1977, Flow Induced Vibration, Reinhold, pp. 320–323.
7.
Chesneau, C., Cavaille, J. Y., and Laures, J. P., 1989, “Complex Modulus Measurements Over a Wide Range of Freq. and Material Characteristics,” Proc. of Damping ’89, FAD pp. 1–22.
8.
Crawley, E. F., and Mohr, D. G., 1985, “Experimental Measurements of Material Damping in Free Fall with Tunable Excitation,” AIAA J., Jan., pp. 125–131.
9.
Derian, E. J., and Hyer, M. W., 1986, “Large Deformation Dynamic Bending of Composite Beams,” NASA Contractor Report 4006, pp. 1–11.
10.
Gibson, R. F., and Plunkett, R., 1977, “A Forced Vibration Technique for Measurement of Material Damping,” Experimental Mechanics, Aug., pp. 297–302.
11.
Gibson, R. F., 1981, “Vibration Damping Characteristics of Graphite/Epoxy Composites for Large Space Structures,” Large Space Systems Technology Review, Nov.
12.
Greif
 
R.
, and
Johnson
 
M. S.
,
1992
, “
A Combined Theoretical/Experimental Approach to the Dynamic Characterization of Viscoelastic Materials
,”
ASME JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY
, Vol.
114
, pp.
77
–
80
.
13.
Hebert, B. F., 1992, “Experimental Techniques for Dynamic Characterization of Composite Materials,” Masters thesis, Tufts Univerity, Medford, Ma.
14.
Johnson, M. S., 1990, “The Relationship Between Epoxy Microstructure and its Dynamic Mechanical Properties,” Masters thesis, Tufts University, Medford, Ma.
15.
Metravib Instruments, 1989, User’s Manual: Viscoanalyzer, DUT 244770/A.
16.
Nashif, A., 1985, Vibration Damping, Wiley and Sons.
17.
Paxson, E. B., 1975, “Real and Imaginary Parts of the Complex Viscoelastic Modulus for Boron Fiber Reinforced Plastics,” J. Acoustical Society of America, Apr., pp. 891–898.
18.
Spirnak, G. T., and Vinson, J. R., 1990, “The Effect of Temperature on the Material Damping of Graphite/Epoxy Composites in a Simulated Space Environment,” ASME JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY, July, pp. 270–279.
19.
Timoshenko, S. P., Weaver, W., and Young, D. H., 1988, Vibration Problems in Engineering, John Wiley and Sons, pp. 44–88.
20.
Wren, G. G., and Kinra, V. K., 1988, “An Experimental Technique for Determining a Measure of Structural Damping,” J. of Testing and Evaluation, Mar., pp. 77–85.
This content is only available via PDF.
Copyright © 1995
 by The American Society of Mechanical Engineers
You do not currently have access to this content.