On the Creep-Stress Analysis of some Structures

Summary

The present paper considers the analysis of some structures in which the deformations are caused exclusively by creep. The paper begins with a discussion of a uniaxial creep law and its generalizations for the analyses of problems in a triaxial state of stress. Moment-curvature rela tions are then developed from these laws for problems in bending, and an elementary device for the inclusion of compressibility effects in creep is briefly discussed. With these as basis, the particular problems considered are, the bemding of thin-walled beams, the bending of annular plates, and the stress distribution in a compressible sphere. In analysing these problems, use has been made of the elastic analogue. Further, in some cases, the similarity of creep to plasticity has also been used. In all cases, closed form solutions have been presented.

The results reported in this paper were obtained in the course of research under Contract No. AF (49) (638) — 302, sponsored by the Air Force Office of Scientific Research and under Contract No. Nonr 839(23), sponsored by the Office of Naval Research of the US Government. The authors are grateful to these organizations for permission to publish the results.