Paper number 932

EXPERIMENTAL AND NUMERICAL DETERMINATION OF STRESS INTENSITY FACTOR IN COMPOSITE MATERIALS

D. Cerniglia1, V. Nigrelli2, and A. Pasta1

1Dipartimento di Meccanica e Aeronautica,
Viale delle Scienze, 90128 Palermo, Italy
2Dipartimento di Meccanica, Strutture, Ambiente e Territorio,
Via G. Di Biasio, 43, 03043 Cassino (FR), Italy

Summary A procedure to obtain stress intensity factors (SIF) employing electrical strain gages, as used for homogeneous isotropic materials, is extended to composite materials. A single edge notched (SEN) specimen of orthotropic carbon-epoxy laminate is used. A suitable computer program gives SIF value by means of measured strain. Least squares method is applied to minimize the errors, using a number of strain gages greater than the bare necessities. The obtained SIF value is compared with that calculated by a program based on the dual boundary element method (DBEM) and the J-integral. Experimental and numerical SIF values are very close. DBEM has allowed to point out that the effects of the orthotropy on SIF are very little.
Keywords fibre-reinforced composites, fracture, boundary element method, strain gages, stress intensity factor.

Theme : Mechanical and Physical Properties ; Fracture Mechanics and Failure

[ HOME ]  [ BACK ]