Flexural behavior of sandwich beams fabricated by vacuum-assisted resin transfer molding

The static and fatigue behavior of vacuum-assisted resin transfer molded sandwich panels has been experimentally investigated under flexural loading. Two core materials, D-100 balsa wood and H 250 PVC foam, were used to study the effect of core material on static failure in 3-point and 4-point bending. The face consisted of a quasi-isotropic E-glass non-woven fabric cured in Derakane 441-400 epoxy vinyl ester resin. The stresses in the face and core at failure were calculated from failure loads using the simple beam theory and compared with their respective strength values to identify underlying failure mechanisms. For short beams, core failure led to failure of the beam as a whole. In long beams, however, failure of the wood core could be contained until the face failed. Only D-100 end grain balsa wood was used as core for fatigue tests. A good similarity was seen between the static and fatigue failure modes for both short span and long span specimens.