Accession Number : ADA303895

Title :   Dynamics of Cracked Composite Material Structures.

Descriptive Note : Final rept. no. 5, 15 Aug 94-15 Aug 95,

Corporate Author : POLISH ACADEMY OF SCIENCES GDANSK INST OF FLUID FLOW MACHINERY

Personal Author(s) : Ostachowicz, W. M. ; Krawczuk, M. ; Zak, A.

PDF Url : ADA303895

Report Date : 15 AUG 1995

Pagination or Media Count : 44

Abstract : As a result of this work models of the finite beam and plate elements have been elaborated, to enable the analysis of the influence of the fatigue cracks and delaminations on the dynamic characteristics of the constructions made of unidirectional composite materials. The method of modelling the crack or delamination presented in the report enables an easy modification of the elaborated elements according to its specific damage (oblique crack, two-side crack, inside crack, multiple delaminations, etc.). The results of numerical calculations obtained from the crack model are in consistence with the known influence of the position and depth of the crack on the decrease of the natural bending frequencies of the cantilever beam. Simultaneously, a strong influence of the maternal parameters on these changes has been observed, which does not exist in the case of isotropic materials. The method of modelling the delamination in composite beams and plates is versatile and allows analysis of the influence of multiple delaminations on natural frequencies of beams and plates with various boundary conditions. Using the elaborated models effects of location and size of delamination on bending natural frequencies of composite beams and plates were studied. (MM)

Descriptors :   *COMPOSITE MATERIALS, *CRACKING(FRACTURING), LAMINATES, FINITE ELEMENT ANALYSIS, CRACKS, DISPLACEMENT, FIBER REINFORCED COMPOSITES, COMPOSITE STRUCTURES, BENDING, RESONANT FREQUENCY, PLATES, ISOTROPISM, FATIGUE(MECHANICS), STRENGTH WEIGHT RATIO, DELAMINATION, CANTILEVER BEAMS.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE