복합재료의 미시역학적 해석을 위한 OFM 모델

Abstract

본 논문에서는 continuous fiber로 이루어진 복합재료의 effective stiffness와 stress distribution을 예측하기 위한 단위셀 모델을 제시 하였다. 이를 위해 하나의 단위셀을 5 X 5 영역으로 나누고 equilibrium condition, geometric compatibility condition, stress-strain relationship을 이용하여 constituent properties 와 stress amplification factor를 식으로 정의 하였다. 다른 해석법과 등가물성치 비교 및 stress distribution 등을 비교해 봄으로써 OFM모델의 타당성을 검증하였다.; We propose a unit cell model which is sub-divided into five by five sub-regions for predicting effective stiffness and stress distributions. Six component stresses and thermal increment are applied to the unit cell, and detailed stress and strain distributions in the sub-regions are obtained by taking into accounts equilibrium conditions, geometric compatibility conditions andthe constitutive stress-strain relationships. Equations for effective stiffness and coefficients of thermal expansion are obtained in terms of constituent properties and the fiber volume fraction. Equations for the stress concentrations, or stress amplification factors in the constituents are also obtained, and make it possible to predict strengths of the composites.