ISSN:
0029-5981
Keywords:
design sensitivity
;
semi-analytic
;
rigid body motions
;
shells
;
Engineering
;
Numerical Methods and Modeling
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Mathematics
,
Technology
Notes:
In the recent past inaccuracy problems have been reported that arise when computing shape design sensitivities by the semi-analytical method. Since both the analytical and the global finite-difference method do not show these severe inaccuracies, it has been concluded that these errors are due to the numerical differentiation of the finite-element stiffness matrices, which is inherent in the semi-analytical method. Moreover, it has also been observed that these inaccuracies become especially dominant when relatively large rigid body motions can be identified for individual elements. So far, improvements to the semi-analytical method are focusing on the numerical differentiation of the finite-element stiffness matrices. It is shown in the present paper that the contribution to the design sensitivities corresponding to the rigid body motions can be evaluated by exact differentiation of the rigid body modes. This approach requires only minor programming effort and the additional computing time is very small. As shown by numerical examples, the proposed method eliminates the problem of abnormal errors occurring in the semi-analytical method. © 1998 John Wiley & Sons, Ltd.
Additional Material:
13 Ill.
Type of Medium:
Electronic Resource
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