Abstract
A method is described for finding stress-strain relations in two principal directions of a sheet material at various values of stress in the cross-direction for material which can be made sensibly gas-holding. Two cylindrical envelopes are made, one of them having the first principal direction of the material circumferential and the second having this direction of the material longitudinal. These are stressed by the application of internal pressure and strain measurements made in axial and circumferential directions. Stress-strain measurements are then made on strips of material in simple tension. Results from these two types of test are combined to give the required curves. The method is illustrated by experiments made on a rubberized fabric.