PL
 |
EN
Ten serwis zostanie wyłączony 2025-02-11.
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 26

Liczba wyników na stronie
first rewind previous Strona / 2 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 2 next fast forward last
1
Nie upolitycznione dzialania i pieniadze.
100%
Malachowski J.
Ekopartner
|
1996
|
nr 11
18-19
2
Content available Field test and numerical studies of the scissors-AVLB type bridge
72%
Krason W. , Malachowski J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2014
|
tom Vol. 62, nr 1
103--112
EN
Scissor bridges are characterized by high mobility and modular structure. A single module-span consists of two spanning parts of the bridge; two main trucks and the support structure. Pin joints are used between modules of the single bridge span. Some aspects of the experimental test and numerical analysis of the scissor-AVLB type bridge operation are presented in this paper. Numerical analyses, presented here, were carried out for the scissors-type BLG bridge with treadways extended as compared to the classical bridge operated up to the present in the Armed Forces of the Republic of Poland. A structural modification of this kind considerably affects any changes in the effort of the force transmitting structure of the bridge. These changes may prove to be disadvantageous to the whole structure because of torsional moments that additionally load the treadways. Giving careful consideration to such operational instances has been highly appreciated because of the possibility of using this kind of bridges while organizing the crossing for vehicles featured with various wheel/track spaces (different from those used previously). The BLG bridge was numerically analysed to assess displacements and distributions of stresses throughout the bridge structure in different loading modes. Because of the complexity of the structure in question and simplifications assumed at the stage of constructing geometric and discrete models, the deformable 3D model of the scissors-type bridge needs verification. Verification of the reliability of models was performed by comparing deflections obtained in the different load modes that corresponded with tests performed on the test stand. It has been shown that the examined changes in conditions of loading the treadways of the bridge are of the greatest effect to the effort of the area of the joint which is attached to the girder bottom. Stress concentrations determined in the analysis are not hazardous to safe operation of the structure.
3
Content available Multibody rigid models and 3D FE models in numerical analysis of transport aircraft main landing gear
72%
Krason W. , Malachowski J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2015
|
tom Vol. 63, nr 3
745--757
EN
Dynamic analyses of a transport aircraft landing gear are conducted to determine the effort of such a complex system and provide capabilities to predict their behaviour under hazardous conditions. This kind of investigation with the use of numerical methods implementation is much easier and less expensive than stand tests. Various 3D models of the landing gear part are defined for the multistage static FE analysis. A complete system of the main landing gear was mapped as a deformable 3D numerical model for dynamic analysis with the use of LS-Dyna code. In this 3D deformable FE model, developed in a drop test simulation, the following matters were taken into consideration: contact problems between collaborating elements, the phenomena of energy absorption by a gas-liquid damper placed in the landing gear and the response of the landing gear during the touchdown of a flexible wheel with the ground. The results of numerical analyses for the selected drop tests and the results from the experiments carried out on a real landing gear were used for verification of FE models and a methodology of the landing gear dynamics analysis. The results obtained from the various simulations of the touchdown have proved the effectiveness of the 3D numerical model and how many problems can be solved in the course of only one numerical run, e.g. geometric and material nonlinearities, a question of contact between the mating components, investigation of the landing gear kinematics, investigation of the energy dissipation problem in the whole system and the stresses influence on the structure behaviour, which can appear in some elements due to overload.
4
Nasze priorytety.
72%
Malachowski J.
Ekopartner
|
1996
|
nr 11
8-9
5
Content available remote Numerical analysis of stent expansion process in coronary artery stenosis with the use of non-compliant balloon
58%
Bukala J. , Kwiatkowski P. , Malachowski J.
|
|
tom Vol. 36, no. 1
145--156
EN
In the paper the authors present an applied methodology, data and numerical results for numerical analysis of the stent crimping process and stent implantation in the coronary artery stenosis with the use of a non-compliant angioplasty balloon. The authors focused on the modeling methodology of balloon angioplasty with minimum possible simplification, i.e.: a full load path (compression and inflation in single analysis), 3D unsymmetrical geometry and discretization, highly nonlinear material models (hyperelasticity, plastic kinematic formulation, crushable foam) and sophisticated contact models (bodies with highly different stiffness). The use of a highly compressible crushable foam material model for an arterial plaque is considered as the most original part of the work. The presented results allow for better understanding of the mechanisms governing stent crimping and implementation.
6
Content available remote Study on computational methods applied to modelling of pulse shaper in split-Hopkinson bar
58%
Baranowski P. , Janiszewski J. , Malachowski J.
|
|
tom Vol. 66, nr 6
429--452
EN
The paper presents a possibility of numerical modelling of a copper shaper utilized in an SHPB device with additional attention paid to the proper bar-shaper interaction simulation. The pulse shaper was modelled with the use of three methods available in the commercial code, i.e., applying typical finite Lagrangian elements, meshless smoothed particle hydrodynamics (SPH) method and multi- material arbitrary Lagrangian–Eulerian (MM-ALE) formulation. Additionally, the authors performed a mesh (particles) sensitivity study and the assessment of its influence on the obtained incident pulse characteristics. Consequently, the results obtained from all numerical analyses were compared and validated with the experimental ones with a particular attention given to the shape of the incident pulse and copper shaper deformation. The paper describes also the investigation of a relationship between the contact (coupling) force and the impulse shape.
7
Miedzynarodowe Forum Edukacji Ekologicznej
58%
Malachowski J.
Ekopartner
|
1996
|
nr 07-08
4-5
8
Na Piastowski Szlaku...
58%
Malachowski J.
Ekopartner
|
1996
|
nr 11
16-17
9
Gospodarka odpadami w sluzbie zdrowia
58%
Malachowski J.
Ekopartner
|
1996
|
nr 05
28
10
Relaks na lonie natury.
58%
Malachowski J.
Ekopartner
|
1996
|
nr 11
20-21
11
Content available remote A child seat numerical model validation in the static and dynamic work conditions
51%
Baranowski P. , Damaziak K. , Malachowski J. , Mazurkiewicz L. , Muszyński A.
Archives of Civil and Mechanical Engineering
|
2015
|
tom Vol. 15, no. 2
361--375
EN
Over last decade, road safety attracts increased attention of EU authorities. EU makers believe that new regulations forcing producers to fulfill extremely difficult safety requirement will help to diminish annual road fatalities. One of the latest of such ideas is standardization of side impact resistance of child seats. Since engineers cannot do anything else but to follow the regulations, number of projects aimed toward improvement of child seats side impact resistance has started. The problem is not easy and thus high-end engineering tools have to be used in the design process. One of such tools – a necessity, if one wants to truly understand structure behavior under dynamic working conditions – is numerical analysis of structures. The very basis of effective usage of this technique is reliable model of an analysis subject. This paper presents detailed information on numerical FE model of child seat and its validation based on test results. Effect of modeling techniques and dynamic material behavior on the obtained results is also discussed. Difficulties that arose during real life test are pointed and its influence on FE modeling is showed up.
12
Content available remote A comparative analysis of popular modern small wind turbine design solutions in terms of estimated cost to power output ratio
51%
Bukala J. , Damaziak K. , Kroszczyński K. , Krzeszowiec M. , Malachowski J.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
|
2014
|
tom nr 146
57--68
EN
In this paper a series of estimations has been performed in order to establish the actual cost-effectiveness of small wind turbines (SWTs). Different design solutions have been evaluated and based on their power curves and installation costs, using accurate wind data, a rate of investment return (ROI) period has been calculated for each one of them. The chosen turbines are: a classic three bladed horizontal axis wind turbine (HAWT), an advanced diffuser augmented HAWT and a Darrieus type vertical axis wind turbine (VAWT). The conclusions drawn from this study entertain the idea that from the economical point of view, a price reduction of SWT systems is more important, than aerodynamic complexity and efficiency.
13
Content available Protokół 1-go zebrania organizacyjnego Polskiego Naukowego Towarzystwa Leśnego odbytego w dniu 5 stycznia 1946 r. w Krakowie
51%
Malachowski J. , Szymkiewicz D.
Sylwan
|
1947
|
tom 91
|
nr 01-04
14
Rady na odpady
50%
Malachowski J.
Ekopartner
|
1996
|
nr 09
9
15
Jubilat ma sie dobrze...[cz.III]
50%
Malachowski J.
|
|
nr 12
12-13
16
Jubilat ma sie dobrze... cz.II
50%
Malachowski J.
Ekopartner
|
1996
|
nr 09
10-11
17
Jubilat ma sie dobrze
50%
Malachowski J.
Ekopartner
|
1996
|
nr 07-08
36-39
18
Content available Thermovision in the validation process of numerical simulation of braking
44%
Baranowski P. , Damaziak K. , Malachowski J. , Mazurkiewicz L. , Polakowski H. , Piatkowski T. , Kastek M.
|
|
tom Vol. 21, nr 2
329--340
EN
This article presents the validation process of a brake FE model by means of temperature measured on a special stand using infrared technology. Unlike many other publications, the authors try to show the interaction between measurement technology and numerical modeling rather than only nice, perfectly correlated graphs. Some difficulties in choosing and using validation parameters are also pointed out and discussed. Finally, results of FE analyses are compared with measured data, followed by explanation of applied numerical technology and estimation of validation process effectiveness.
19
Content available Numerical study for determination of pulse shaping design variables in SHPB apparatus
44%
Baranowski P. , Malachowski J. , Gieleta R. , Damaziak K. , Mazurkiewicz L. , Kołodziejczyk D.
|
|
nr 2
20
Content available Investigation of the stress-strain state of seamless pipe in the initial state
44%
Malachowski J. , Hutsaylyuk V. , Yukhumets P. , Dmitryenko R. , Beliaiev G. , Prudkii I.
Archive of Mechanical Engineering
|
2014
|
tom Vol. LXI, nr 4
595--607
EN
Mechanical properties of the pipeline samples that had been cut in annular and axial directions were investigated. The methodology of modeling and calculation of the real stress-strain state was described. The stable state during in the deformation process was defined. The results of the experimental researches were used as a test variant during examination of pipe strength.
PL
W pracy przedstawiono wyniki badań właściwości mechanicznych materiału z próbek wyciętych z rury bezszwowej na kierunku obwodowym i osiowym. Zaproponowano metodykę modelowania i szacowania stanu naprężenia i odkształcenia. Jest ona zgodna z metodologią stosowaną do analiz wytrzymałościowych cienkościennych cylindrycznych i sferycznych zbiorników poddanych ciśnieniu wewnętrznemu. W weryfikacji wyników wykorzystano wyniki badań doświadczalnych.
first rewind previous Strona / 2 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.