Accession Number : ADA302051

Title :   Large Deformation Dynamic Bending of Composite Beams.

Descriptive Note : Interim rept. Sep 83-Apr 86,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ENGINEERING SCIEN CE AND MECHANICS

Personal Author(s) : Derian, E. J. ; Hyer, M. W.

PDF Url : ADA302051

Report Date : AUG 1986

Pagination or Media Count : 219

Abstract : Studies were conducted on the large deformation response of composite beams subjected to a dynamic axial load. The beams were loaded with a moderate eccentricity to promote bending. The study was primarily experimental but some finite element results were obtained. Both the deformation and the failure of the beams were of interest. The static response of the beams was also studied to determine potential differences between the static and dynamic failure. Twelve different laminate types were tested. The beams tested were 23 in. by 2 in. and generally 30 plies thick. The beams were loaded dynamically with a gravity-driven impactor traveling at 19.6 ft/sec and quasi-static tests were conducted on identical beams in a displacement controlled manner. For laminates of practical interest, the failure modes under static and dynamic loadings were identical. Failure in most of the laminate types occurred in a single event involving 40% to 50% of the plies. However, failure in laminates with 300 or 150 off-axis plies occurred in several events. All laminates exhibited bimodular elastic properties. The compressive flexural moduli in some laminates was measured to be 1/2 the tensile flexural modulus. No simple relationship could be found among the measured ultimate failure strains of the different laminate types. Using empirically determined flexural properties, a finite element analysis was reasonably accurate in predicting the static and dynamic deformation response. (MM)

Descriptors :   *COMMERCIAL AIRCRAFT, *COMPOSITE MATERIALS, *LAMINATES, *BEAMS(STRUCTURAL), *DEFORMATION, *FIBER REINFORCED COMPOSITES, *COMPOSITE STRUCTURES, *TRANSPORT AIRCRAFT, FINITE ELEMENT ANALYSIS, LOADS(FORCES), DYNAMIC RESPONSE, DISPLACEMENT, BENDING, DATA ACQUISITION, FAILURE(MECHANICS), FLEXURAL PROPERTIES, STATIC TESTS, AXIAL LOADS, COMPRESSIVE PROPERTIES.

Subject Categories : Commercial and General Aviation
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE