Abstract
In this paper, the “FRP” plate is considered as continuous body having orthotropic elasticity in the region of infinitesimal deformation, and an analytical method is presented for calculating its orthotropic elastic compliance Sij. The conditions given for the calculation are the structure of the composite system and the elastic constants of the fiber and the resin. A typical example treated mainly in this paper is cloth reinforced plastic. The plate is consisted of two parts, one is the part of yarn having some resin which can be treated as an uni-directionally reinforced plastic rod, and the part of pure resin. The property of resin part is isotropic, but the yarn part has orthotropic property. It is assumed that the orthotropic property of the FRP plate has been caused by this orthotropic character of the yarn parts by the angle between the yarn axis and the direction load. The uniform deformation of all parts in the FRP plate is also assumed.
Good agreement between calculated values and observed one for elastic constant has been confirmed by some experiments in which model samples made of single layer FRP plates was used.
