REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

OPTIMIZATION OF THE BOX SECTION OF THE SINGLE-GIRDER BRIDGE CRANE BY GRG ALGORITHM ACCORDING TO DOMESTIC STANDARDS AND EUROCODES

Goran Pavlović

Lola Institut, Belgrade, goran.pavlovic@li.rs

Vladimir Kvrgić

Lola Institut, Belgrade, vladimir.kvrgic@li.rs

stefan mitrović

Lola Institut, Belgrade, stefan.mitrovic@li.rs

Mile Savković

Faculty of Mechanical and Civil Engineering in Kraljevo, Kraljevo, savkovic.m@mfkv.kg.ac.rs

Nebojša Zdravković

Faculty of Mechanical and Civil Engineering in Kraljevo, Kraljevo, zdravkovic.n@mfkv.kg.ac.rs

Abstract: The paper considers the problem of optimization of the box section of the main girder of the single-girder bridge crane. Reduction of the area of the box cross section is set as the objective function. The algorithm of generalized reduced gradient (GRG2 algorithm) was used as the methodology for determination of optimum geometrical parameters of the box section. The criteria of permissible stresses, local stability of plates, lateral stability of the girder, static deflection, dynamic stiffness, minimum plate thickness  and production feasibility (distance between the webs) were applied as the constraint functions. Verification of the used methodology was carried out through numerical examples and the comparison with some existing solutions of cranes was made. The comparative optimization results show changes of the box section optimum geometric values due to domestic standards or eurocodes.

Keywords: single-girder bridge crane,box section, optimization, GRG2 algorithm, eurocodes.