RESPONSE OF THICK LAMINATED COMPOSITE RINGS TO THERMAL-STRESSES

Thermal stress analysis of a thick laminated ring is presented. The layers of the ring are assumed cylindrically orthotropic. The analysis is based on treating the ring in plane stress in the (r-theta) plane. If the rings is cut through radially at a point, the ring may open or close depending on the values of the stress resultants due to thermal stresses. The analysis predicts such opening or closing displacements which then are compared with the measured values. It is found that the moment stress resultant due to the thermal hoop stress determines the value of the opening or closing displacements, and that the moment stress resultant, as expected, is strongly dependent on the stacking sequence of the wound layers. It is also found that the effect of the thermal stresses can be minimized by gradually reducing the hoop stiffness of the layers from inside to outside the ring.