Parametric optimization of frequency oscillation minimum surface shell on a rectangular contour under thermal load

Providing all parameters according to two groups of limit states at the design stage is a multi–criteria task. Optimal helps perform such tasks. When phenomenon resonance occurs, it necessary change frequency forced oscillations load–bearing structures various tanks and coatings in order ensure sufficient strength stability structure building general. For this purpose, there separate type problem optimal that allows us frequencies using example shell minimum surface on rectangular contour.
 In mathematical point view, tasks are optimization tasks, finding extremum target function (maximum or minimum). Methods solving problems can be conditionally divided into groups. One them will include methods based conditions for objective function. The second group includes methods: linear, convex dynamic programming, random search methods. application modern requires powerful PCs with large RAM, therefore, when choosing optimization, take account capabilities computer equipment.
 algorithm single–criteria parametric performed as follows: weight contour, variables thickness from 1 50 mm, constraints presented first oscillation 0,15 Hz.
 Using software complex Femap Nastran our own software, single–criterion was made. results changing reducing by 2300 kg C240 steel, which equivalent 10,3% without losing contour. author's methodology possible an effective calculation