Multiaxial/biaxial loading tests of fibre-reinforced polymer-matrix co
mposite materials are reviewed, and results of these experimental inve
stigations under both monotonic and cyclic loadings are discussed. It
is noted that composite materials could exhibit complicated behaviour
in the biaxial loading conditions which often exist in engineering pra
ctice. The importance of biaxial loading tests of composites is indica
ted by this assessment.