Wyniki wyszukiwania - BazTech

1

Weight minimization of spatial trusses with genetic algorithm

Grzywiński Maksym, Selejdak Jacek

Quality Production Improvement - QPI

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2019

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Vol. 1, Iss. 1

238--243

EN

A genetic algorithm is proposed to solve the weight minimization problem of spatial truss structures considering size and shape design variables. A very recently developed metaheuristic method called JAYA algorithm (JA) is implemented in this study for optimization of truss structures. The main feature of JA is that it does not require setting algorithm specific parameters. The algorithm has a very simple formulation where the basic idea is to approach the best solution and escape from the worst solution. Analyses of structures are performed by a finite element code in MATLAB. The effectiveness of JA algorithm is demonstrated through benchmark spatial truss 39-bar, and compare with results in references.

2

Variable thickness approach for finding minimum laminate thickness and investigating effect of different design variables on its performance

Kulkarni N. S., Tripathi V. K.

Archive of Mechanical Engineering

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2018

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Vol. LXV, nr 4

527--551

EN

The performance of majority engineering systems made of composite laminates can be improved by increasing strength to weight ratio. Variable thickness approach (VTA), in discrete form, used in this study is capable of finding minimum laminate thickness in one stage only, instead of two stage methodology defined by other researchers, with substantial accuracy for the given load conditions. This minimum required laminate thickness can be used by designers in multiple ways. Current study reveals that effectiveness of VTA in this regard depends on ply thickness increment value and number of plies. Maximum Stress theory, Tsai Wu theory and Tsai Hill theory are used as constraints, while ply angles, ply thicknesses and number of plies in discrete form are used as design variables in current simulation studies. Optimization is carried out using direct value coded genetic algorithm. The effect of design variables such as ply angles, ply thicknesses and number of plies in discrete form on optimum solution is investigated considering Uniform Thickness Approach (UTA) and Variable Thickness Approach (VTA) for various load cases.

3

Optimal control for elasto-orthotropic plate

Lovišek J., Králik J.

Control and Cybernetics

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2006

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Vol. 35, no 2

219-278

EN

The optimal control problems and a weight minimization problem are considered for elastic three-layered plate with inner obstacle and friction condition on a part of the boundary. The state problem is represented by a variational inequality and the design variables influence both the coefficients and the set of admissible state functions. We prove the existence of a solution to the above-mentioned problem on the basis of a general theorem on the control of variational inequalities. Next, the approximate optimization problem is proved on the basis of the general theorem for the continuous problem. When the mesh/size tends to zero, then any sequence of appropriate solutions converges uniformly to a solution of the continuous problem. Finally, the application to the optimal design of unilaterally supported of rotational symmetrical load elastic annular plate is presented.