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Open access

Vít Sháněl and Miroslav Španiel

Abstract

This paper details the numerical modeling of composite absorbers and an assessment of the influence of such deformation elements on a bus during frontal collision with a car. The absorber itself is designed as an assembly of thin-walled composite wound tubes oriented in the vehicle direction of travel. During the impact the tubes are crushed, causing energy absorption. Crash simulations were performed at various speeds using differing scenarios with the deformational member as well as without it. Comparative diagrams of force and velocity of the car and deformation of the bus structure were assessed

Open access

Hynek Štekbauer and Ivan Němec

Abstract

The cable-pulley system is widely used for its advantages. In this paper, application of a new algorithm for the calculation of cables on pulleys is presented. Unlike other algorithms, this algorithm enables to take the magnitude of the radius of each pulley into account. This new algorithm is implemented in the RFEM program because of its higher accuracy and efficiency. Comparison of the commonly used algorithm, which ignores pulley radius, and the new algorithm is presented.

Open access

Miroslav Džupon, Ľuboš Kaščák, Dušan Németh and Réne Kubík

Abstract

A tool with a punch of ø5 mm and a die with a specially formed circular cavity and an annular gap was used for mechanical joining of thin hot-dip galvanized steel sheets. The active parts of punch and die were covered by PVD coating of ZrN type with LARC technology. The punches and the dies were tested in a complex tool by joining thin hot-dip galvanized steel sheets with the pressing force of 7,000 N. Decohesion of coating with width of 100 – 200 μm was observed in the perimeter of cylindrical part of ø5×4 mm in the in edge of punch radius R = 0.5 mm with deposited ZrN coating after the creation of 150 mechanical joints. The decohesion of PVD coating occurred mainly in the surroundings of the radius R = 0.5 mm on the front plane of ø15 mm part.

Open access

Paweł Sidun and Andrzej Łukaszewicz

Abstract

In this paper selected aspects of numerical modelling of bending pipes process are described. Elasto-plastic material model was used in COMSOL FEM environment. The results of numerical analyses of two kinds of steel were presented. The correctness of the proposed model was verified based on comparison shapes of deformed pipe profile obtained at the ending step of bending both from numerical simulations and experiment.

Open access

Grzegorz Porembski and Janusz Kozak

Simulation of damage process of containership's side structure due to collision with a rock

This paper presents methods and results of a simplified numerical simulation of collision process of containership's side structure and a rock. Analysis of results of the modeling makes it possible to draw conclusions as to a character of the event as well as to estimate area and depth of damage caused by the penetrating rock, in order to select geometry of a filler and impermeable layer of 2nd protection barrier.

Open access

J. Bartnicki

This paper presents the results of numerical calculations of rolling extrusion process of a hollow hub. Simulations were made by means of software Deform 3D in three dimensional state of strain. Distributions of effective stress, effective strain and damage criterion in the rolled extruded product were analyzed. Verification of metal flow during process allowed to design tools for experimental verification in PO-2 laboratory rolling - extrusion aggregate. For these needs also process force parameters were calculated.

Open access

Marinela Inţă, Achim Muntean and Cristian Petrianu

Abstract

The paper intends to implement the use of theoretical models and computer aided simulation based on FEM for improving the teaching of cutting metals theory for the students of Machine Manufacturing Technologies and Machine Tools. The advantage of simulation, especially animated is to transpose the normal classroom into a virtual model where the skills can be evaluated under similar realistic conditions. It helps the students to be able to face the complexity of the real complex processes inside the production environment. A review of the most important models in cutting processes shows that the majority of the researches in this field tend to replace the traditional methods of calculating the cutting data parameters based on mathematical models with new complex models. The paper tries to relieve the importance of using the FEM models and simulation software for a better understanding of the process and also for providing more accurate and more detailed information. In the case studied in this paper a series of experimental models were performed for a validation of the theoretical models created by comparing the results. The advantages of using 2D and 3D animated models in the teaching and training process are also mentioned in the paper.

Open access

Z. Pater, J. Tomczak and T. Bulzak

Abstract

The paper describes a new method for producing stepped rail axles. The method is based on the skew rolling process. With this method, the product is formed by three tapered rolls located every 120° on the perimeter of the billet. Positioned askew to the centerline of the billet, the rolls rotate in the same direction and with the same velocity. At the same time, they get closer together or go apart depending on the desired cross sectional reduction of an axle step. In addition, the workpiece is shifted lengthwise relative to the rolls by the translational motion of the workpiece-holding chuck. In order to verify the designed method for producing rail axles, a series of numerical simulations were performed using the Simufact. Forming v.12 simulation software. The numerical modeling enabled the determination of maps of the effective strain and temperature in the finished product as well as variations in the loads and torques during rolling. The numerical results unambiguously confirm that the skew rolling method can be applied to form parts of considerable dimensions (the modeled axles had a length of 2146 mm and their maximum diameter was 202 mm).

Open access

M. Miśkiewicz, Ł. Pyrzowski, M. Rucka, K. Wilde and J. Chróscielewski

Abstract

This paper presents the study of the impact of vibration induced by the movement of the railway rolling stock on the Forum Gdańsk structure. This object is currently under construction and is located over the railway tracks in the vicinity of the Gdańsk Głowny and Gdańsk Środmieście railway stations. The analysis covers the influence of vibrations on the structure itself and on the people within. The in situ measurements on existing parts of the structure allow us to determine environmental excitations used for validation and verification of the derived FEM model. The numerical calculations made the estimates of the vibration amplitudes propagating throughout the whole structure possible.

Open access

S. Sobieszczyk, W. Wojnicz and B. Nowak

FEM Approach to Estimate the Behaviour of Biocomposite Metal-Surface Coating Systems

A three dimensional (3D) model of biocomposite metal-surface coating system, which is influenced by known external forces, is proposed. This model consists of the metallic substrate (Ti6A14V) and the hydroxyapatite (HA) coating. Using FEM (finite element method), strain-stress maps of model were generated for investigating relations between the extreme stress of HA coating and the magnitude of external force and the thickness of the coating. The analysis of numerical simulations results confirms that the system with the greatest coating thickness (i.e. 10-3 m) has the least extreme stress in this surface coating.