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Tytuł:
Problemy projektowania i analizy struktury regałów wysokiego składowania
Problems of design and analysis of a structure of racking uprights
Autorzy:
Dalewski, R.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/208461.pdf
Data publikacji:
2006
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
MES (metoda elementów skończonych)
projektowanie konstrukcji
konstrukcje cienkościenne
FEM
structural design
thin-walled construction
Opis:
Praca zawiera wstępny opis projektowania konstrukcji cienkościennych pełniących rolę filarów konstrukcji regałowych i ich połączeń z pozostałymi elementami konstrukcji. Omówione zostały aspekty wyznaczania nośności konstrukcji w zależności od występujących postaci zniszczenia - wyboczenia lokalnego, dystorsyjnego i globalnego elementów konstrukcji, uplastycznienia.
The paper presents preliminary study of thin-walled designs employed in racking uprights. Also the joints of these constructions with other elements are described here. The authors describe some aspects of determination of construction strength regarding various modes of buckling and plasticity.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2006, 55, 4; 183-190
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza powierzchni kontaktu w połączniu nitowym
Analysis of contact surface in riveted joints
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/211058.pdf
Data publikacji:
2007
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
naprężenia kontaktowe
MES (metoda elementów skończonych)
analiza fraktograficzna
contact stress
FEM
fractography
Opis:
Celem pracy jest analiza rozkładów naprężeń (w szczególności naprężeń kontaktu) w połączeniu nitowym w aspekcie niszczenia powierzchni nitu i blach wywołanego cyklicznym rozciąganiem zakładkowego połączenia nitowego. Badania przeprowadzono dla próbek konstrukcyjnych wykonanych z cienkich blach aluminiowych połączonych stalowymi nitami. Materiały oraz wymiary próbek zostały dobrane tak, aby podczas cyklicznego rozciągania połączenia wystąpił intensywny fretting oraz kontrolowane niszczenie próbki w wybranej strefie. Wykonano symulacje MES procesu nitowania na prasie oraz obliczenia numeryczne w celu wyznaczenia obciążeń powodujących zerwanie rozciąganego statycznie połączenia i określenia sposobu niszczenia próbki. Przeprowadzono badania statyczne i zmęczeniowe próbek nitowanych oraz analizę fraktograficzną stanu powierzchni połączenia.
The papers deals with the analysis of contact stress fields and inspection of fretting phenomena in the neighbourhood of mating surfaces of the lap riveted joint subjected to cyclic load. The specimens are made of thin aluminium sheets connected by steel rivets. Chosen shape and dimensions of the sample ensures predictable and repetitive failure behaviour. Many undersirable phenomena, like electro-chemical corrosion, occur in a riveted joint due to different material properties of steel and aluminium alloy. This situation causes reduction in fatigue life and it is suitable for observing surface damage. Simulation of a riveting process is performed to obtain post riveting residual stress fields and deformation. Numerical FEM calculations are also carried out to estimate tearing (ultimate) force and to observe the mechanism of the specimen failure. Static and fatigue tests of tensile loaded lap riveted specimens and fractographic (SEM) analysis are performed.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2007, 56, 4; 75-84
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selected problems concerning the analysis of thin-walled structures with the use of finite element method
Autorzy:
Jachimowicz, J.
Mańkowski, J.
Osiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/243328.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
diagonal tension
wing structures
thin-walled structures
aircraft
FEM
modelling
Opis:
The aim of the paper was presentation and comparison of numerical methods applied in thin-walled structures analysis, with special attention paid to possibility of usage the Finite Element Method (FEM), especially in nonlinear analysis. There were presented basic differences between classical approach to modelling and analyzing thin-walled structures, and these performed with FEM methods using. The biggest emphasis was placed on the analysis of semimonocoąues, in which the loss in the shell 's stability is possible in the range of operational load activity. According to this, many nonlinear terms like global and local buckling, contact problems, significant deformations and shifts, are present. Worth emphasizing is the fact, that tension field, is something that was described long time ago. First paper s about this phenomenon were published in the last century. Although it is a common effect that takes place in semimonocoques, there are not many publications that analyze and examine this phenomenon. In this paper, an analysis of two-sided, thin-walled spar, which has undergone the flexion by the shearing force in the plane of the panel, was presented. The spar was designed as a classic semimonocoque, in which load transmission function is separated. It was assumed that, for the sake of small thickness, shell elements transmit mainly tangential loads, normal loads, when normal loads are transmitted by framework elements. Riveted joints are used to join elements of framework and shell. There are presented and compared results of analysis for models with various complexities. Firstly, results of analysis of classical model of semimonocoques were presented. It means that framework elements were modelled as rod elements transmitted only normal loads, but shell elements were modelled as disc semimonocoque elements, in this case transmitted only tangential loads. Area of section of rod elements was adequately increased, in order to consideration mating width, coming from partial transmission of normal loads by the shell elements. Results obtained for intermediate models were also presented, as well as for complex shell model, which allows on advanced nonlinear analysis of tension field, which consider contact between framework and shell elements. Applications of formulated models to thin-walled structure, especially aircraft ones and further possibilities of presented method of analysis were discussed.
Źródło:
Journal of KONES; 2008, 15, 1; 109-118
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods for Global and Local FEM Analysis of Riveted Joint on the Example of the PZL M28 Skytruck Aircraft
Autorzy:
Wronicz, W.
Kaniowski, J.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/97845.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Opis:
The paper considers some aspects of FEM modeling of riveted joints with application of shell elements and submodeling technique. Presented works were carried out within Eureka project No. E!3496 called IMPERJA. The goal of the IMPERJA project is to increase the fatigue life of riveted joints. The project assumed FEM modeling of the operating aircraft’s structure at three different complexity levels, namely considering the complete structure, a structural detail and a single riveted joint. The paper presents analyses of various rivet models and calculations of a structure and a riveted joint. In the first part examples of various rivet models were presented and usefulness of them was discussed. Influence of the following simplification was analyzed; • neglecting of rivets in a model (elements are jointed continuously) • rivet as a rigid element (MPC) • neglecting of contact phenomenon • neglecting of secondary bending. The basis of the analysis was the asymmetric butt joint model with 14 rivets. The model which took into account secondary bending and contact phenomenon was analyzed as well. In the second part, the example of analysis of riveted joint on a lower skin of the PZL M28 Skytruck aircraft wing was presented. A submodeling technique was used there. At first, part of the wing model, was built. It includes 7 ribs and 6 bulkheads between them. Boundary conditions were taken on a basis of operation data. Presence of rivets was neglected. The Linear material model was used. The purpose of this calculation was to gain accurate boundary conditions for the model of riveted joint on the middle rib. Next a shell model of chosen area was build. Boundary conditions were set on a basis of result from previous analysis. Because of large stiffness difference between part models (part of wing and riveted joint) forces, instead of displacements, were used, as boundary conditions. The nonlinear model of material was used. A contact effect, secondary bending and residual stresses were taken into account. Results from this analysis are planned to be used as boundary conditions in a calculation of single rivet with solid detailed model. The presented method allows analyzing phenomena that appear around a rivet in a real structure, during operation. Analyses were performed with MSC PATRAN and NASTRAN software.
Źródło:
Fatigue of Aircraft Structures; 2009, 1; 212-225
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of load transfer into composite structure
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Puchała, K.
Powiązania:
https://bibliotekanauki.pl/articles/118025.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
mechanical joint
adhesive joint
composite material
load transfer
FEA
Opis:
The paper presents advantages and disadvantages of metal foils insertion between composite layers. Composites are complex materials of aniso-tropic structure leading to various failure mechanisms. Mechanism of compressive load transfer into composite laminates by shear of the matrix is analysed. The method of improvement compressive strength of laminates is presented according to literature and analysed for a sele-cted case. Simplified models of a laminate structure modified using various metal foils configurations are analysed with MSC.Marc code. Axial stress in prepreg layers and shear stress in adhesive layers are studied.
Źródło:
Applied Computer Science; 2014, 10, 3; 86-94
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
About mechanical joints design in metal - composite structure
Autorzy:
Puchała, K.
Szymczyk, E.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/246795.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
mechanical joint
adhesive joint
FEA
aviation
Opis:
Riveting is still one of the main joining methods of thin-walled aircraft structures. Such features as simplicity of implementation, possibility of two different material connection (e.g. metallic with non-metallic ones) and the fact that is it a well-known (reliable) method causes popularity of riveting. The never-ending attempt to obtain as low mass as possible (mainly to reduce fuel consumption) is the reason for using material of high specific strength in the aerospace industry. High strength titanium or aluminium alloys (e.g. 2024T3) and composite laminates (e.g. CFRP or Glare) are examples of such materials. The article deals with methods of connecting various materials. The paper presents advantages and disadvantages of different/selected connection types. Strength prediction and failure modes of mechanical joints are described for metallic as well as for composite components. Composites are complex materials having an anisotropic structure (and anisotropic mechanical properties) leading to various failure mechanisms. Main principles for appropriate joint design of composite laminate panels (laminate configuration and typical/specific geometrical dimensions) are indicated/specified. The bearing failure mechanism is accepted to be a safe progressive one. Mechanism of bearing (generally compressive) load transfer into composite laminates by shear of the matrix is analysed. Some examples of improvement bearing strength of laminates are presented according to literature. On the base of presented examples and bearing load transfer analysis, some conclusions for an appropriate solution of this problem are drawn.
Źródło:
Journal of KONES; 2012, 19, 3; 381-390
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Friction coefficient determination based on the results of ball – on - flat test
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Prasek, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/248003.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
friction coefficient
ball-on-flat test
FFT
Opis:
The interaction of contacting surfaces in relative motion is basic for every engineering design. The transmission of load from one rubbing surface to its mating surface under conditions of dry contact is taken into account. Microlocal or global models of friction are used to describe this phenomenon. In global approach, frictional force is proportional to normal load. A coefficient of external friction depends on the type, shape, and precision of finishing the surfaces of mating elements. The aim of the paper is analysis of a friction coefficient for 2024T3 aluminium alloy during cyclic tangential loading. Experimental tests are carried out on a ball-on-flat wear-testing machine Ducom. Tests of reciprocating friction are carried out using the following friction pairs of specimens: the ball specimen is made of high strength aluminium alloy PA25 and the plane specimen is made of 2024T3 alloy. Finally, graphs of temporary friction coefficients versus time in the form of fluctuated periodical functions are obtained. Two phases of friction are detected. However, during the first stage, the friction coefficient is relatively small while in the second period it rapidly increases and tends to become more irregular. Static and dynamic friction coefficients are estimated. In order to determine the dynamic coefficient the Discrete Fourier Transformation is used. The calculation of the dominant amplitude (corresponding to test frequency) of the studied functions is possible due to this method. An increase of the friction coefficient with an increase of normal load is observed. A cladding layer also causes an increase of friction, especially in the second phase.
Źródło:
Journal of KONES; 2012, 19, 1; 415-422
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of residual stress fields in the riveted joint
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Derewońko, A.
Powiązania:
https://bibliotekanauki.pl/articles/243089.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveted joint
FEM local model
non-destructive testing methods
Opis:
The riveted joints are critical areas of the aircraft structure. The residual stress and strain state appears at the rivet hole after the riveting process and improves fatigue behaviour of the joint. Numerical FE simulations of the upsetting process are carried out using the MARC code. Three-dimensional numerical models are used to determine the resulting stress and strain fields at the countersunk rivet and around the hole. The contact with friction is defined between the mating parts of the joint. Calculations are carried out in an elastic-plastic range. The influence of the rivet geometry, rivet stiffness and the sheet material model on strain and stress states is studied. Non-destructive testing methods like X-ray diffraction, liquid penetrant inspection and visual detection analysis with a UV lamp are used for validation of numerical results. Comparison between numerical and experimental results gives a satisfactory agreement. Numerical simulations allow investigating the influence of imperfections on the strength of the joint.
Źródło:
Journal of KONES; 2007, 14, 2; 465-473
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Possible Replacement of the Aluminum Spar with a Composite Structure Illustrated with the Case of Agricultural Aircraft
Autorzy:
Fałek, M.
Szymczyk, E.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/98018.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
composite structure
agricultural aircraft
airplane wing
Opis:
Composite materials are increasingly being used in aviation. Specific stiffness and strength of composite materials (especially CFRP laminate, sandwich structure) are higher compared to metal alloys. They are beneficial features of materials used in aviation. Mass reduction of aircraft structures (e.g. due to the use of composite materials) contributes to an aircraft’s better performance in terms of its range, top speed and ceiling and consequently causes an increase in airplanes capacity. Moreover, the use of high-strength and lightweight materials in aviation contributes to longer life time and lower exploitation costs. The aim of the paper was the study the possibilities of replacing the aluminum spar of an airplane wing with a composite structure. In order to compare the mass and strength of the aluminum with the composite spar, the global shell and local solid models were created and finite elements analysis was performed. The analysis was carried out for the front spar of the wing of the agricultural aircraft PZL-106.
Źródło:
Fatigue of Aircraft Structures; 2017, 9; 85-99
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stateczność cienkościennych powłok cylindrycznych poddanych uderzeniu płytą sztywną
Stability of thin-walled cylinders subjected to impact load by a rigid plate
Autorzy:
Miedzińska, D.
Jachimowicz, J.
Dziewulski, P.
Powiązania:
https://bibliotekanauki.pl/articles/208828.pdf
Data publikacji:
2010
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
utrata stateczności
powłoki cylindryczne
wyboczenie
energia kinetyczna
dynamic stability
thin-walled cylinder
kinetic energy
crush elements
instability
Opis:
W artykule przedstawiono wyniki dynamicznych analiz numerycznych procesu wyboczenia cienkościennej powłoki cylindrycznej poddanej obciążeniom uderzenia nieskończenie sztywną płytą, której nadano różne wartości energii kinetycznej. Pokazano wpływ tej energii na proces deformacji powłoki oraz na wartości sił krytycznych, przy których konstrukcja traci stateczność. Przedstawiono ogólne równania metody elementów skończonych używanych do obliczeń procesów dynamicznych.
The results of dynamic numerical analyses of stability of thin-walled steel cylinders exposed to an impact load from an infinitely rigid plate with variable kinetic energy were presented. The influence of this energy and velocities on the deformation process and critical force values (forces causing the instability) was shown. Also the theoretical bases of the instability phenomenon were presented as well as the FEM formulas for dynamic processes.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2010, 59, 1; 131-141
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of break shoes wearing in drum break - numerical approach
Autorzy:
Damaziak, K.
Jachimowicz, J.
Małachowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/246894.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
road transport
simulation
brakes
thermal dynamic computations
Opis:
Braking system is one of the key components influencing passenger safety. Today, a design process of brakes is usually experience - driven, based on brake manufactures know - how. Using this approach, it is fairly difficult predict the brake components exact working condition or durability - parameters still more often required in a modern design process, what results in a rising demand for an exact simulation of a braking process. This paper presents numerical analyses of a drum brake. Both static and dynamic FE analyses were conducted in order to verify behaviour of numerical procedures affecting the braking process. The phenomena of heat generation by friction forces and the influence of a wear pattern was emphasized during dynamic calculations, while static analyses were focused on sensitivity to thermal properties of materials. FE models, including loads and boundary conditions, are described in details. Some of the data used during the simulation were taken from experiments. These laboratory tests are also briefly described in the paper. Based on the obtained results, it is shown that a numerical procedure converting sliding energy coming from friction to heat used in a coupled mechanical - thermal dynamic calculation works properly, but is very sensitive to material thermal properties. Proper FE modelling of the contact area and contact forces is also crucial. Unfortunately, due to lack of real material data, the presented results have quantitive character only.
Źródło:
Journal of KONES; 2010, 17, 2; 81-87
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some aspects of dynamic riveting simulations
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Puchała, K.
Powiązania:
https://bibliotekanauki.pl/articles/248006.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveting
dynamic simulation
residual stress state
Opis:
Riveting is a commonly used (especially in aircraft structures) method of joining metal and composite components. The methods of forming solid shank rivets can be classified in two types: static and dynamic. The static method is the most efficient one. Regrettably, its application is limited. A popular upsetting tool used in an aircraft is a pneumatic riveter. The rivet driving requires a few hammer strokes. The total stress in a riveted joint depends on the residual and applied stress. Residual post-riveting stress fields are widely accepted to have a beneficial influence on the fatigue life of aircraft structures. The analysis is carried out for a solid mushroom rivet (made of PA25 alloy) joining two sheets (made of 2024T3 alloy). Nonlinear dynamic simulations of the upsetting process are carried out. Simulation of the riveting process is significantly influenced by a material model. The numerical calculations are performed for three different cases of upsetting described by the formed rivet head diameters 1.4d, 1.5d and 1.6d, respectively. The rivet head diameter and, consequently, the residual stress state depend on hammer stroke energy. It has a significant influence on a plastic region around the rivet hole, whereas the influence of a number of strokes can be neglected. The strain rate in both local and global (average) formulation is analysed in the paper. For one hammer stroke, the global strain rate of the rivet shank is about 1.0 thousand per second. The local strain rate is about two times greater than the global one, so a strain rate factor has an effect on the residual stress state. For a few hammer strokes, the strain rate is lower than for one stroke; however, it increases a little in each stroke. The hole deformation can be treated as a function of the internal energy of the sheet. The lower total energy of the part the greater influence of the strain rate on the internal energy is observed.
Źródło:
Journal of KONES; 2012, 19, 1; 423-430
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Riveting process simulation - upsetting of the mushroom rivet
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Sławiński, G.
Powiązania:
https://bibliotekanauki.pl/articles/244023.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveted joint
mushroom rivet
FEM local model
stress and strain fields
Źródło:
Journal of KONES; 2008, 15, 2; 493-502
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Termograficzne pomiary okładzin ciernych hamulców
Thermographics measurements of brake pad lining
Autorzy:
Piątkowski, T.
Polakowski, H.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/155824.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
tarcie
parametry cieplne
termografia
emisyjność
friction
thermal parameters
thermography
emissivity
Opis:
Opracowanie nowej generacji hamulców wymaga wykonania pomiarów rozkładów temperatury na powierzchniach jego elementów konstrukcyjnych. W pracy przedstawiono wybrane wyniki takich badań metodami termograficznymi. W rezultacie tych badań określono obszary o podwyższonej temperaturze, temperaturę maksymalną oraz szybkość zmian temperatury. Porównano otrzymane wyniki z pomiarami metodą stykową. Dane otrzymane w wyniku analizy termogramów pozwolą na weryfikację modelu numerycznego hamulca.
Braking process has rather short duration (5s÷15s) and during that time the kinetic energy of a vehicle is transformed into heat. Such amount of heat generates thermal shock to braking pads and discs. Development of a new type of brakes requires measuring temperature distributions on their working surfaces. The paper presents some selected results of such measurements performed on a modified IL-68 test rig by means of thermal imaging (Fig. 2). Two types of composite braking pad materials were tested: C/C and 500/EBC. C/C composite is used for aircraft brakes, whereas 500/EBC type is used for brakes of all-terrain ground vehicles. Due to high dynamics of the thermal signal, the measurements were taken in the range from 200?C to 750?C. The data from the thermal images were processed using IR Control software. As a result there were identified the high temperature areas (hot spots), maximum temperature values for each recorded frame and the rate of temperature changes during braking (Fig. 5) as well as cooling down (Fig. 6) phases. The frame-by-frame analysis of the recorded thermal image sequences made it possible to correlate the temperature distribution non-uniformity with structural defects of the tested brake pads. The results of temperature measurements were compared with those obtained from the contact method (Fig. 7). On that basis, the errors of non-contact temperature measurements were estimated. The analysis of the recorded thermal images allowed calculating several thermal parameters, such as thermal time constants of particular brake elements (1), (2). Those data were used to verify the numerical model of the brake. They also can be the guidelines to optimise the brake design with respect to heat transfer aspects.
Źródło:
Pomiary Automatyka Kontrola; 2011, R. 57, nr 11, 11; 1285-1288
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numeryczne modelowanie zagadnienia kontaktu w procesie spęczania nitu
Numerical modelling of a contact problem in the rivet upsetting process
Autorzy:
Derewońko, A.
Szymczyk, E.
Jachimowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/208471.pdf
Data publikacji:
2006
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
MES (metoda elementów skończonych)
proces nitowania
zagadnienie kontaktu
połączenia nitowe
FEM
riveting process
contact problem
riveted joint
Opis:
Celem pracy jest dobór modelu numerycznego (właściwej siatki elementów skończonych) zapewniającego prawidłowe odwzorowanie współpracy kontaktujących się powierzchni nitu i blachy w procesie spęczania trzpienia nitu. Stanowi ona jeden z etapów badania lokalnych zjawisk fizycznych w połączeniach nitowych lotniczych konstrukcji cienkościennych [1-8]. Analizy z uwzględnieniem zagadnienia kontaktu i dużych odkształceń wykonano metodą elementów skończonych w programie MSC.Marc. Wyniki obliczeń numerycznych porównano z wartościami sił i naprężeń oszacowanymi analitycznie dla spęczanego swobodnego walca. Uzyskane numerycznie rozkłady naprężeń i odkształceń są zgodne z prezentowanymi w literaturze [13], co wskazuje, że proces zakuwania trzpienia nitu został odwzorowany poprawnie. Deformacje powierzchni kontaktu na granicy nitu i blachy wykazują dużą wrażliwość na parametry siatki elementów skończonych. Właściwy sposób podziału współpracujących brył na elementy skończone pozwala uniknąć wzajemnego przenikania węzłów, a tym samym niefizycznych koncentracji naprężeń w obszarze kontaktu.
The paper deals with numerical simulation of rivet upsetting in a hole. The work is aimed at a choice of numerical model (proper finite element mesh) that ensures suitable behaviour of the rivet and sheet hole surfaces during rivet's upsetting process. This is preliminary stage of an analysis of the local physical phenomena in the riveted joints of an aircraft structure. A contact problem and large strains are taken into consideration in FEM analysis performed with MARC code. Numerical results are compared with analytical estimations for upsetting a cylindrical specimen. Numerical stress and strain fields show that squeezing the rivet shank is correctly described. The deformations of contact surface between the rivet and the hole are sensitive on finite element mesh parameters. Due to appropriate meshing of the mating components, mutual node penetration and consequently, non-physical stress concentration on the contact surfaces can be avoided.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2006, 55, 4; 89-100
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 28

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