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1

Numerical analysis of I-beam supporting structure with multimaterial protective panel - parametric study

Damaziak K., Mazurkiewicz Ł., Małachowski J., Klasztorny M., Baranowski P.

Journal of KONES

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2012

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Vol. 19, No. 3

93-102

EN

Dynamic response of an I-beam supporting structure subjected to shock wave produced by the detonation of high explosive materials is presented in this paper. Dynamic response of structural components in different load cases-with multimaterial panel protection and without protection, subjected to blast wave from various charge weight and various distance stand-off was determined. LS-DYNA, a 3-D explicit, finite element computer code with Lagrangian-Eulerian coupling was used to study this behaviour. Also initial static load was taken into account as pre-stress field present in the column obtained using dynamic relaxation procedure. The protective panel is composed of fibreglass composite and aluminium foam. The composite orthotropic properties and the failure criteria for fibre and matrix damage as well as the stress-volumetric strain curve for metallic foam were taken into account. The previous study shows that critical to the structure durability are the plastic strains and the structure failure caused by high deformation. Results of the analyses indicate that application of the blast panel around the supporting structure increase the resistance and significantly reduce the plastic deformation of the structure. The pillar without protection can be destroyed by 2 kg TNT placed close to the structure. Analysed beam covered by the blast panel can resist over three times bigger charge without significant deformation of the structure.

2

Analysis of selected structural components subjected to blast wave

Mazurkiewicz Ł., Małachowski J.

Journal of KONES

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2012

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Vol. 19, No. 1

267-272

EN

The phenomenon of high-energy explosion of a substance such as the mixture of flammable gases, explosives, etc. is highly exothermic chemical reaction that causes a blast wave consisting of hot gases at high pressure. Very complex nature of the phenomenon of detonation, affects the need for advanced methods of analysis. In the present work analysis of two steel columns (I-section and tubular section) subjected to the blast wave are presented. The columns have similar values of the moments of inertia and mass per unit length. To describe the complex phenomena occurring in gas medium the Eulerian formulation was used. The steel structures were described using Lagrangian formulation. Interaction between domains was achieved by numerical coupling algorithm with implemented penalty function. From the results from all the analysis cases, the dynamic response of structural elements was obtained. Permanent deformation and the amount of absorbed energy are of special interest in this study. The resultant velocity vectors were also presented to illustrate the characteristic of blast wave propagation.

3

Numerical simulations of granular material flow in silos with and without insert

Wójcik M., Tejchman J

Archives of Civil Engineering

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2007

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Vol. 53, nr 2

293-322

EN

The paper describes results of finite element simulations of confined granular flow in silos with inserts. Attention is laid to the flow pattern and wall pressure distribution during filling and emptying of silos. The calculations are carried out with a finite element code Abaqus. The behaviour of the granular material is described with an isotropic elasto-perfectly plastic constitutive model based on a Drucker-Prager failure criterion. The numerical analysis is performed with the help of an uncoupled Arbitrary Lagrangian-Eulerian (ALE) approach. The calculations are carried out for a plane strain model silo and an axisymmetric large silo assuming different initial densities of sand, wall friction angles, types, shapes and positions of inserts. The numerical results are compared with laboratory experiments and tests in a large silo.

PL

Przedstawiono numeryczne wyniki zachowania się materiału sypkiego podczas przepływu w silosie z wkładkami. Nacisk położony został na wyznaczenie naporu materiałów sypkich na ściany. Analiza numeryczna przeprowadzona została za pomocą metody elementów skończonych i programu ABAQUS, Zastosowano przestrzenno-materialny opis ruchu tzw. "Arbitary Lagrangian-Eulerian". Własności mechaniczne piasku modelowano przy użyciu prostego modelu spreżysto-plastycznego według Druckera-Pragera. Obliczenia wykonane zostały dla modelowego silosu (w płaskim stanie odkształceń) oraz dla dużego osiowo-symetrycznego silosu. W obliczeniach uwzględniono różne początkowe zagęszczenie piasku, szorstkość ścian oraz różny kształt i pozycje wkładek. Wyniki numeryczne porównane zostały z wynikami badań doświadczalnych.