Inelastic Strain Analogy for Piecewise Linear Computation of Creep Residues in Built-up Structures
Jenkins, Jerald M. (1987) Inelastic Strain Analogy for Piecewise Linear Computation of Creep Residues in Built-up Structures. Technical Report NASA TM-86813, Research Engineering, NASA Dryden Flight Research Center.
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Abstract
An analogy between inelastic strains caused by temperature and those caused by creep is presented in terms of isotropic elasticity. It is shown how the theoretical aspects can be blended with existing finite-element computer programs to exact a piecewise linear solution. The creep effect is determined by using the thermal stress computational approach, if appropriate alterations are made to the thermal expansion of the individual elements. The overall transient solution is achieved by consecutive piecewise linear iterations. The total residue caused by creep is obtained by accumulating creep residues for each iteration and then resubmitting the total residues for each element as an equivalent input. A typical creep law is tested for incremental time convergence. The results indicate that the approach is practical, with a valid indication of the extent of creep after approximately 20 hr of incremental time. The general analogy between body forces and inelastic strain gradients is discussed with respect to how an inelastic problem can be worked as an elastic problem.
| EPrint Type: | NASA Technical Memorandum |
|---|---|
| Keywords: | Creep, Material properties |
| Subjects: | (31 - 39) Engineering: (39) Structural Mechanics |
| ID Code: | 503 |
| Deposited On: | 23 January 2006 |
| Additional Information: | 13 pages. |
