Donatas Jatulis

Mast behaviour analysis and peculiarities of numerical modelling

Abstract Paper is assigned to numerical analysis peculiarities of masts applying specialised computer‐aided design packages. Masts deformable behaviour is described as non‐linear one. The test problem of mast is solved by two widely applied in Lithuania computational packages STAADpro and Robot Millennium and the specialised programme for mast design SUDM. A corrected analytical method for mast guy analysis, taking into account a force component, acting along the guy supports. A performed numerical experiment is aimed to clarify the possibilities of the above‐mentioned numerical analysis instruments for geometrical non‐linear modelling of structure. The accuracy errors when determining the mast stress and strain fields by numerical analysis packages comparing with the ones obtained by a corrected analytical method are indicated. Possibilities of employing the considered computer‐aided design programming packages for practical design of masts are discussed.

Static behaviour analysis of masts with combined guys

Abstract The purpose of this study was to develop a new type of guyed mast that incorporates a complex guy cable system with a particular focus on the effect of static loading on the response mast behaviour. The intension of such solution is to increase a number of elastic supports for the mast shaft that will impact on its stability under loading. The static analysis of a one‐level guyed mast has been undertaken. The effects of geometrical and physical design parameters on the displacements of the mast were determined. The analysis is illustrated with two‐guyed masts: the bending moments and lateral displacements were determined for a typical guyed mast and guyed mast with combined guys.

Technical and economical effectiveness of the combined guys mast

Santrauka Straipsnyje aptariama nauja plieninio stiebo konstrukcija, kurioje taikomos kombinuotosios atotampos. Analizuojamas sios naujos konstrukcijos techninis ekonominis veiksmingumas pagal medžiagu sanaudu kriteriju. Pateikiamos analizines israiskos racionaliems stiebo kamieno lenkiamiesiems momentams apskaiciuoti ir rekomendacijos atotampu tvirtinimo koordinatems nustatyti. Atliktu skaitiniu eksperimentu parodyta, kad nauju kombinuotuju atotampu taikymas leidžia sumažinti bendrasias stiebo medžiagu (plieno) sanaudas.

Some insights on the optimal schemes of tall guyed masts

AbstractThe article presents the technique for simultaneous topology, shape and sizing optimisation of tall guyed masts under wind loadings and self-weight using simulated annealing. The objective function is the mass of the mast structure including guys, while the set of design parameters may consist of up to 10 parameters of different nature. The constraints are assessed according to Eurocodes and include the local and global stability constraints, limitations on the slenderness in mast elements, and strength constraints. The proposed optimisation technique covers three independent parts: the optimisation algorithm, meshing pre-processor that yields computational scheme of mast depending on the design parameters, and finite element program evaluating the objective function and constraints via penalisation technique. As an example the results of optimisation of a typical 60 m tall guyed telecommunication mast with different antenna areas are presented. On the basis of these results, the authors try ascer...

Optimization of Rigidly Supported Guyed Masts

A technique for simultaneous topology, shape, and sizing optimization of tall guyed masts is presented in this paper. The typical scheme of telecommunication masts that are triangular in plan and supported by a certain number of guys’ levels is examined. The objective function is the total mass of the mast, including the mass of the guys. The mast structure is optimized for self-weight and wind loading that is evaluated according to Eurocodes. The nonlinear behaviour of the guyed mast is simplified idealizing the nonlinear guys as approximate boundary conditions for the mast. A comparison of the simplified solution with the results of nonlinear analysis with Ansys shows small discrepancies that are on the safe side. The constraints involve all strength, local and global stability, and slenderness requirements. The optimization problem is solved using evolutionary algorithm with original genome repair procedure. As an example, a typical 96 m guyed broadcasting antenna for mobile-phone networks was designed employing the proposed optimization technique and taking up to 10 guys’ levels. It is shown that the optimal mast is supported by 3–5 guys’ levels. The optimal ranges of all remaining design variables were also obtained.