EFFECT OF NATURAL LOAD ON DELAMINATION BEHAVIOUR OF A NEW HYBRID WOVEN COMPOSITE

Abstract

The objective of this work is to develop a delamination model that can predict delamination growth in a new woven composite for orthopedic use. This new composite is obtained from a laminated composite woven by incorporating a natural organic load (granulates of date cores) which becomes hybrid composite. The new composite is made of an organic matrix containing methyl methacrylate, a woven reinforcement including a reinforcing glass fiber and a fabric perlon having an absorbing role. The walk cycle has been used to determine the operating conditions of tibiae prosthesis. Hence, the deflection tests were validated by orthopedist experts. 3ENF tests were carried out on the new woven composite to detect delamination phenomenon. We assume that the interface has a bi-linear softening behaviour and regarded as being a whole of several interfacial bonds. Each bond is supposed to be made up of three stiffnesses acting in the three delamination mode directions.

A scalar damage variable is introduced and the degradation of the interface stiffness is established. A damage surface which combines stress-based and damage-mechanics-based failure criteria is set up to derive the damage evolution law. The damage model is implemented into a commercial finite element ANSYS to simulate delamination in mode II. Numerical results on (90, 45₂, 0) are in good agreement with experimental observations.

DOI: http://dx.doi.org/10.5755/j01.mech.18.5.2692