Nonlinear Bending and Buckling of Oblate Ellipsoidal Shells with Variable Thickness Under External Pressure and Temperature Change

The effect of low and high temperatures on the nonlinear axisymmetric strain in oblate semi-ellipsoidal shells of variable thickness with a fully clamped base under the action of an external uniform pressure is numerically studied. The relations of the theory of Timoshenko type shells are used, taking into account the geometric and material nonlinearities. The problem is solved by a combination of successive approximations and orthogonal sweeping. The dependence of material characteristics on temperature is taken into account. The variable thickness is determined by the equal strength condition for the membrane ' s stress-strain state. It is shown that the limit loads of the considered shells of variable thickness in a wide range of temperature changes noticeably increase in comparison with the limit loads of shells of constant thickness in a similar volume. In this case, the greatest critical loads for all considered shells are observed at cryogenic temperatures, and at elevated temperatures, their values decrease significantly.