Thermal stress analysis of thick laminated rings due to the difference between curing and operating temperature is performed. The layers of the ring are assumed cylindrically orthotropic. The analysis is based on treating the rings in plane stress in (r-$\theta$) plane. If the ring is cut through radially at a point, the ring may open or close depending on the values of the stress resultant due to the thermal stress. Four types of rings are fabricated and tested. Strain gages are located centrally on the inside and the outside surfaces of each ring at four equally spaced polar positions. Opening or closing displacement and strain are measured after cutting each ring along a generator midway between adjacent pairs of gages. The measured values are then compared with the analysis. Also, an analytical investigation on the influence of controlling parameter such as temperature difference and the ratio of thickness to radius and material of mandrels upon opening and closing displacement is performed. It is found that the moment resultant mostly determines the opening or closing displacements and the moment resultant is strongly dependent of the stacking sequence of wound layers.
