Use of ADINA for design optimization of nonlinear structures

This paper analyses the design sensitivity of a sus- t+'~tu(i)pension system with material and geometric nonlinearities for a motorcycle structure. The main procedures include nonlinear t+2tt~j(1) structural analysis, formulation of the problem with nonlinear dynamic response, design sensitivity analysis, and optimization, t+At~j(i) The incremental finite dement method is used in structural analysis. The stiffness and damping parameters of the suspension AU(1) system are considered as design variables. The maximum amplitude of nonlinear transient response at the seat is taken as the V objective function during the optimization simulation. A more

Section: Analysis Of the Resultsmentioning

confidence: 94%

Design sensitivity analysis and optimization of nonlinear dynamic response for a motorcycle driving on a half-sine bump road

Sun

1996

“…The approach developed in the present paper allows one to obtain corresponding estimates in the case of the absence of buckling effects, as it was done in many papers (e.g. Haririan et al 1987).…”

Section: Introductionmentioning

confidence: 96%

On optimal physically nonlinear trusses

Selyugin

1995

Optimization problems for physically nonlinear hyperelastic trusses statically loaded by a single system of loads are investigated. Several possible formulations of the problems for a prescribed truss layout are considered. It is demonstrated that the problems lead to the design of equal absolute stress values in some rods and of active technology constraints in other rods. Some general properties of the trusses are examined. Optimal physically nonlinear hyperelastic truss layout problems under static loading are also considered. It is shown that the well-known results of Maxwell, Michell and Prager concerning linear-elastic structures are generalized for the considered problems. It is demonstrated that the results of the paper are extended to optimization probl~ems for structures in stationary creep with an arbitrary concave stress-strain velocity relation.

“…Wu and Arora (1987) used the incremental scheme to derive the derivatives of nonlinear response, and to develop sensitivity analysis for stress, strain, displacement and buckling load constraints. Finally, the integration of structural analysis, design sensitivity analysis, and numerical optimization was developed for implementation into a finite element computer program (Harrian et al 1987;Arora and Cardoso 1989;Kumar et al 1989). The situation at present is that the general formulation of design sensitivity analysis with nonlinear response has been developed in an almost routine manner.…”

Section: Introductionmentioning

confidence: 99%

Weight optimization for flexural reinforced concrete beams with static nonlinear response

Chung

Sun

1994

The weight optimization of reinforced concrete (RC) beams with material nonlinear response is formulated as a general nonlinear optimization problem. Incremental finite element procedures are used to integrate the structural response analysis and design sensitivity analysis in a consistent manner. In the finite element discretization, the concrete is modelled by plane stress elements and steel reinforcement is modelled by discrete truss elements. The cross-sectional areas of the steel and the thickness of the concrete are chosen as design variables, and design constraints can include the displacement, stress and sizing constraints. The objective function is the weight of the RC beams. The optimal design is performed by using the sequential linear programming algorithm for the changing process of design variables, and the gradient projection method for the calculations of the search direction. Three example problems are considered. The first two are demonstrated to show the stability and accuracy of the approaches by comparing previous results for truss and plane stress elements, separately. The last one is an example of an RC beam. Comparative cost objective functions are presented to prove the validity of the approach.