Analytical and experimental investigations into fibre/matrix sandwich beams and columns.

The sandwich construction is a relatively light weight but stiff system which can be manufactured from a large variety of materials. The aircraft and transportation industries are probably the greatest end users of this form of construction. The units manufactured for these industries are usually shaped to increase further the overall stiffness of the composite. The present investigation compares the experimental testing of beams under varying bending moments with four analytical solutions, three of which were based upon the finite element method and the fourth was based upon theory. In addition it compares the experimental results of edgewise compressive loads applied to sandwich systems with two analytical solutions, one was a finite element analysis and the other a theoretical solution. Mechanical property tests were also determined on small coupon samples cut from the same material from which the beams and columns were made. These are required as input data for the finite element solutions. It has been shown that, generally, there is satisfactory agreement between the analytical and experimental techniques used. The foam core material is a particularly difficult material to model when it is considered that it is highly anisotropic and contains a high percentage of air voids. The analytical solutions used in the analysis allowed for only small deflection theory; greater accuracy may have been achieved using a theory considering large deflections