doi:10.3850/978-981-08-7920-4_S2-S55-cd

ABSTRACT

The paper presents an approach to shape optimization of proportionally loaded elastic shell structures under various constraints, including stability. To reduce the stability-related problems, a special technique is utilized, by which the response analysis is always terminated before the first critical point is reached. In that way, the optimization is always related to a pre-critical structural state. The necessary load-carrying capability of the optimal structure is assured by extending the usual formulation of the optimization problem by a constraint on an estimated critical load factor. Since limit points are easier to handle, the possible presence of bifurcation points is avoided by introducing imperfection parameters. They are related to an asymmetric shape perturbation of the structure. During the optimization, the imperfection parameters are updated to get automatically the ‘worst-case’ pattern and amplitude of the imperfection. Both, the imperfection parameters and the design variables are related to the structural shape via the design element technique.

Keywords: Structures, Optimization, Stability, Shells, Shape design, Imperfection.

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