Formulation of the nonlinear analysis of shell-like structures, subjected to time-dependent mechanical and thermal loading. Interim technical report, 15 April 1984-14 April 1986
A general mathematical model and solution methodologies for analyzing the structural response of thin, metallic shell structures under large transient, cyclic, or static thermomechanical loads was sought. Among the system responses associated with these loads and conditions are thermal buckling, creep buckling, and ratcheting. Thus geometric and material nonlinearities (of high order) can be anticipated and must be considered in developing the mathematical model. A complete, true ab-initio rate theory of kinematics and kinetics for continuum and curved thin structures, without any restriction on the magnitude of the strains or the deformations, was formulated. The time dependence and large strain behavior are incorporated through the introduction of the time rates of metric and curvature in two coordinate systems: fixed (spatial) and convected (material). The relations between the time derivative and the covariant derivative (gradient) was developed for curved space and motion, so the velocity components supply the connection between the equations of motion and the time rates of change of the metric and curvature tensors. A time and temperature dependent viscoplasticity model was formulated to account for finite strains and rotations.
- Research Organization:
- Georgia Inst. of Tech., Atlanta (USA)
- OSTI ID:
- 7141805
- Report Number(s):
- N-86-28462; NASA-CR-177194; NAS-1.26:177194
- Country of Publication:
- United States
- Language:
- English
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