Strength scaling in fiber compositesA research program was initiated to study and isolate the factors responsible for scale effects in the tensile strength of graphite/epoxy composite laminates. Four layups were chosen with appropriate stacking sequences so as to highlight individual and interacting failure modes. Four scale sizes were selected for investigation including full scale size, 3/4, 2/4, and 1/4, with n = to 4, 3, 2, and 1, respectively. The full scale specimen sizes was 32 piles thick as compared to 24, 16, and 8 piles for the 3/4, 2/4, and 1/4 specimen sizes respectively. Results were obtained in the form of tensile strength, stress-strain curves and damage development. Problems associated with strength degradation with increasing specimen sizes are isolated and discussed. Inconsistencies associated with strain measurements were also identified. Enchanced X-ray radiography was employed for damage evaluation, following step loading. It was shown that fiber dominated layups were less sensitive to scaling effects compared to the matrix dominated layups.
Document ID
19910047327
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Kellas, Sotiris (Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Morton, John (Virginia Polytechnic Institute and State University Blacksburg, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1991
Subject Category
Structural Mechanics
Report/Patent Number
AIAA PAPER 91-1144
Meeting Information
Meeting: AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference