Minimum weight design of axisymmetric sandwich plates

Abstract

The problem of minimum weight design of laminated circular sandwich plates with axial symmetry is formulated using optimal control theory. A steepest descent algorithm is used to solve the resulting two point boundary value problem. Inequality constraints on minimum face and core thicknesses, maximum stress levels and maximum displacement are included. Both statically determinate and statically indeterminate plates are considered. Several examples are presented illustrating the general configuration of minimum weight designs and the dramatic weight savings attainable.

Optimum Design of Composite Structures: A Literature Survey (1969–2009)

“…In order to avoid unacceptable configurations, constraints are imposed on the design variables during an optimization process; e.g. a minimum stiffness is ensured by imposing an upper limit for deflections, 1,3,12,18,25,28,34,38,42,47,49,59,84,122,123,127–129,131,143,145,146,156,165,200,222,225,227,238,240,256,258,261,265,269,272,282,283,293,315,344,351,360,403,410,412,413,419,422,423,437,469,470,476,498,500,503,520,530,552,563,565,568,…”

“…886 Other than behavioral constraints, side constraints may be applied; e.g. design space may be restricted to positive values of thickness and cross-sectional area 50,51,529 ; as side constraints, upper and lower limits may be set for lamina or laminate thickness 8,18,25,36,47,50,51,53,59,61,69,74,82,84,86,92,96–100,102,105,106,108,109,120,122,123,136,140,141,144,147,157,162,181,182,192,200,202,206,217,230,231,238,240,267,274,283,285,288,292,299,305,308,318,326,330,…”

Optimization of Sandwich Monocoque Car Body with Equivalent Shell Element

“…Although concise results, such as optimal face to core weight ratios [4], analytical formulas [5,6], and design charts [7,8] are convenient for designers, they are not generally applicable for structures with compli-* Graduate student ** Professor, corresponding author cated geometry and loading conditions. Some optimization focuses on face-fiber orientations, while others consider the thicknesses and material constants of the faces and core as design variables [9]. Few works on optimizing large and complex sandwich structures have been done, except for commonly using the thickness of the faces and core with predetermined materials as design variables [10,11].…”