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Wyszukujesz frazę "residual stresses" wg kryterium: Temat


Tytuł:
An efficient implementation of boundary conditions in an ALE model for orthogonal cutting
Efektywne sformułowanie warunków brzegowych w modelowaniu procesu skrawania we współrzędnych Lagrange-Eulera (ALE)
Autorzy:
Miguelez, M. H.
Munoz-Sanchez, A.
Cantero, J. L.
Powiązania:
https://bibliotekanauki.pl/articles/279416.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
residual stresses
orthogonal machining
ALE
boundary conditions
Opis:
Prediction of machining-induced residual stresses is an interesting objective in the field of modelling manufacturing processes. Although Finite Element Analysis (FEA) has been widely used for this purpose, many problems are found when the numerical model is developed. Computational cost and numerical problems related to the extreme mesh distortion make the effort of finite element modelling of machining extremely time consuming. The aim of this work is to predict machinning-induced residual stresses using a finite element model based in ALE (Arbitrary Lagrangian Eulerian) approach. The finite element general-purpose code ABAQUS is used, modifying the previous model used in scientific literature to predict residual stresses. Boundary conditions in the entrance of the workpiece and in the upper border of the chip were modified from Lagrangian boundaries in the previous model, to Eulerian boundaries in the new model. Main advantages of the model presented in this work are low level of distortion of the mesh, the possibility of simulate long length of machined surface and time-efficiency. The model has been applied to calculate residual stresses in AISI 316L during machining. Reasonable agreement with experimental results has been found.
Przewidywanie szczątkowych naprężeń wywoływanych obróbką skrawaniemw materiale próbki stanowi interesujące zagadnienie modelowania tego typu technologii wytwarzania. Mimo, że analiza oparta na elementach skończonych znalazła szerokie zastosowanie w tej dziedzinie, jej skuteczność jest problematyczna na poziomie budowy modelu numerycznego. Koszt symulacji i kłopoty obliczeniowe związane z ogromnym zniekształceniem siatki elementów skończonych czynią ten rodzaj analizy wyjątkowo czasochłonnym. Celem tej pracy jest opis metody określania naprężeń szczątko- wych indukowanych obróbką skrawaniem za pomocą modelu z elementami skończonymi w opisie eulerowsko-lagrange'owskim ALE (ang. Arbitrary Lagrangian Eulerian). W obliczeniach zastosowano wielozadaniowy pakiet ABAQUS, który pozwolił na modyfikację dotychczas stosowanego modelu, opisanego w literaturze. Warunki brzegowe w obszarze wejścia noża w obrabiany materiał i górnej strefie wióra zmodyfikowano z typu Lagrange'a na Eulera w nowej wersji. Zaletą tego rozwiązania okazało się małe zniekształcenie siatki elementów skończonych, możliwość symulacji długich powierzchni obróbczych i znacznie krótszy czas obliczeń. Model wykorzystano do określenia naprężeń szczątkowych w stali AISI 316L podczas skrawania. Potwierdzono satysfakcjonującą zgodność symulacji z wynikami pomiarów doświadczalnych.
Źródło:
Journal of Theoretical and Applied Mechanics; 2009, 47, 3; 599-616
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of residual stress fields and sheet thickness on stress distributions in riveted joint
Autorzy:
Szymczyk, E.
Powiązania:
https://bibliotekanauki.pl/articles/243841.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveted joint
residual stresses
secondary bending
FEM
Opis:
Riveting is a traditional, but still popular (particularly in aviation) method of joining metal and composite elements. The residual stress and plastic strain states occur in the joint after the riveting process. The total stress aperienced by the material at a given location within a component depends on the residual and applied stress. Residual post-riveting stress fields are widely accepted to have a significant influence on the fatigue life of aircraft structures. The single lap riveted joint consisting of two sheets and three rows of rivets are analysed. Two specimens are taken into consideration: sheet width and pitch distance are equal to 10.5 mm and rivet diameter is equal to 3.5 mm in the former case whereas 25 mm wide sheets and 5 mm rivet diameter are used in the later case. Distance between rivets (pitch length) and sheet width are equal to 3 or 5 rivet diameters. Materials used in riveted joints are subjected to plastic deformation. The rivet (PA24) and the sheet (2024T3) aluminium alloys are described using piecewise linear material models. The yield stress for the multiaxial state is calculated using the von Mises yield criterion. The paper deals with analysis of the pitch length and sheet thickness influence on stress fields. Stress concentrations around the holes in the rivet row and its distribution between rows are calculated. Models with and without residual stresses are taken into consideration. Local change of the sheet thickness causes a decrease in secondary bending of the joint. This is a result of a small increase in bending between the rivet rows and a simultaneous decrease in maximum bending stress values.
Źródło:
Journal of KONES; 2010, 17, 1; 441-448
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling the Effects of Residual Stresses on Electro-Magnetic Properties of Super Alloys
Autorzy:
Goetz, S.
Chandra, D.
Veselova, D.
Klocke, F.
Powiązania:
https://bibliotekanauki.pl/articles/100051.pdf
Data publikacji:
2015
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
aerospace components
eddy current testing
residual stresses
Opis:
Super Alloys, commonly used in safety-critical aerospace components, regularly impose problems when machined in drilling or milling processes, resulting in surface damages that facilitate cracks. Residual stresses are often induced to prevent crack mitigation, but national aviation agencies set high quality standards on them. Current methods are either destructive or impose safety risks for the employees. Eddy current methods, however, are fast and cheap non-destructive methods to receive information on metallic surfaces. They rely on electro-magnetic properties of the material. The influence of residual stresses on both permeability and conductivity are not yet fully understood. This article presents a simple model that describes the correlation between residual stresses and those aspects. At first, the dependency of permeability and conductivity on various metallurgical properties, such as grain size or orientation, is deduced. In a second step, the influence of residual stresses on these properties is shown. A third step combines both steps into a coherent and holistic model to describe the influence of residual stresses on the electro-magnetic properties of Super Alloys. This model will help establishing Eddy Current Testing in the product monitoring in the aerospace industry.
Źródło:
Journal of Machine Engineering; 2015, 15, 3; 33-40
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Residual stresses measurements with X-ray diffractometry on aluminum specimens - determination of the most suitable parameters of measurement
Autorzy:
Gadalińska, E.
Kaniowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/245743.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
X-ray diffractometry
residual stresses
fatigue
aluminum alloys
Opis:
The work was done as apart of the IMPERJA Eureka Project. The goal of the IMPERJA project is to increase the fatigue life of riveted joints, which will lead to an increase of the aircraft service life, a smaller number of inspections and lower operation costs of an aircraft. The consortium intends to meet this goal by investigating and improving the riveting process as well as improving the prediction methods for fatigue life. Riveting is the most commonly used method of joining sheet metal components of the aircraft structure. Typically, the number of rivets ranges from several thousands to some millions in a single aircraft depending on the specific aircraft type and size. The riveted joints are critical areas of the aircraft structure due to severe stress concentrations and effects such as fretting and secondary bending. Therefore the fatigue crack initiation will start at the rivets holes. Fatigue crack initiation usually occurs at a number of rivet holes (multiple site damage), which may lead to widespread fatigue damage and reduced residual strength. Although the literature on the fatigue behaviour of riveted joints is quite abundant, many aspects are still not sufficiently understood and investigated and, therefore, they require a further study. The work contains the results of stress measurements obtained with X-ray diffractometer. The aim of the work was to determine the stress values after different kinds of treatment, to check what are the limits of the x-ray measurement for aluminum alloys and to obtain the most suitable measurement parameters for this kind of alloy. There were 5 kinds of specimens: -specimen no. l - technically pure aluminum, specimen annealed in temperature 300° C for l hour, -specimen no. 2 - technically pure aluminum, raw state without any additional treatment, -    -specimen no. 3 - technically pure aluminum, squeezed perpendicularly to the axis direction, force: l00 kN, longitudinal intersection, specimen no. 4 - technically pure aluminum, squeezed perpendicularly to the axis direction, force: 100 kN, transverse intersection, specimen no. 5 - PA24 alloy, 05 bar, squeezed along the axis of the rod, force: l3,9 kN, longitudinal intersection. The second part of the work contains the measurements of the stress distribution around the rivets. The specimen prepared to realize this kind of measurements had four areas. The rivets on every area were riveted with the different riveting force: 1.2 kN; 1.4 kN; 1.5 kN and 1.55 kN.
Źródło:
Journal of KONES; 2009, 16, 4; 123-134
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Single-Stage and Duplex Shot Peening on Surface Roughness and Residual Stresses in Al Mg5 Mn1 Sc0,8 Zr0,4 Alloy
Autorzy:
Byczkowska, P.
Sawicki, J.
Januszewicz, B.
Stegliński, M.
Powiązania:
https://bibliotekanauki.pl/articles/353741.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
shot peening
double shot peening
residual stresses
roughness
Opis:
Conventional shot peening (SP) is cheap surface treatment widely used to enhance fatigue life of mechanical components [3,4]. Basically, it is shooting small particles (shots) on the surface of the sample. However, the process itself is so complex that a lot of companies are not able to optimally employ it due to the amount of parameters that must be controlled all at the same time. The duplex process consists in two stages of shot-peening treatment. The first one consist of shot-peening with spherical cast steel shots or cut wire shots. During the second stage the samples processed in stage one were subject to shot-peening with glass beads. In this work, RSA-501 aluminium alloy was shot peened using shots of different material and diameter and tested using a measurement of residual stresses and surface roughness. Tests and studies conducted so far on RSA-501 aluminium alloy demonstrate that bombardment by a treatment medium in the form of glass beads or shots of various shapes and diameters induces permanent plastic deformation of the surface layer. The roughness achieved after the shot-peening process was determined for each treatment medium. The largest value of Ra parameter was achieved for cut wire shots and this result is consistent with the above-mentioned theoretical knowledge. This medium is the most aggressive one to the surface being treated primarily due to the sharp edges of shots. The duplex process was successful in obtaining higher values of compressive stresses in surface layer than values achievable in conventional single-stage shot peening process.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 505-511
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Analysis of Twist Extrusion Pressing of Al-Mg-Mn-Sc-Zr Scalmalloy
Autorzy:
Sawicki, J.
Świniarski, J.
Stegliński, M.
Byczkowska, P.
Powiązania:
https://bibliotekanauki.pl/articles/355673.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminium alloys
twist extrusion
numerical analysis
residual stresses
Opis:
Twist extrusion is a processing method involving the extrusion of a sample with a prismatic cross-section using a tool composed of four prismatic parts bisected by a screw component. A beneficial change in mechanical durability is one of the main factors enabling the use of highly durable Al-Mg-Mn-Sc-Zr alloys to construct functional components of non-stationary robots. As part of the present research, ANSYS® software was used to simulate a twist extrusion process. An analysis of a sample entering and passing through the entire twisting area was performed, up to the point of full twisting of the base of the sample. The stress conditions in the sample were analysed as it passed through the twisting area. The highest stress values (reaching up to 600 MPa) were detected at the tips of the sample face as the sample exited the twisting area. The lowest stress values, at around 170 MPa, were detected at the side edges of the sample.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1385-1392
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Shot Peening on the Fatigue Strength of Automotive Tubular Stabilizer Bars DC 218
Autorzy:
Wittek, A. M.
Gąska, D.
Łazarz, B.
Matyja, T.
Powiązania:
https://bibliotekanauki.pl/articles/353092.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
shot-peening
residual stresses
fatigue
finite element method
Opis:
This paper concerns issues related to the development of designs of stabilizer bars for new motor vehicle models. It involves not only the designing of a stabilizer bar with the shape required by the manufacturer, but also the preparation of bending and heat treatment processes as well as the performance of strength and fatigue tests. In the prototype development phase, the simulations techniques (FEM) may be used to assess the design. The article contains a detailed analysis of a stabilizer bar designated with the DC 218 VA symbol. Performed numerical strength and fatigue calculations showed that the developed stabilizer bar design with the desired shape did not achieve the required number of fatigue cycles. It was also proven at the test stand by testing a prototype stabilizer bar. Therefore, it was suggested to supplement the technological process with an additional shot peening operation whose main aim was to reduce the length of microcracks on the stabilizer bar’s surface. This effect was confirmed during comparative metallographic tests of not shot – peened and shot – peened stabilizer bars. After shot peening, the analysed stabilizer bar reached a fatigue strength which exceeded the limits set by the manufacturer.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 1963-1968
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Residual Stresses Measurement in the Weld Seam of X70 Steel, Analyzed by XRD
Autorzy:
Hamdi, M.
Benhorma, H.
Hadjaj, A.
Benchatti, A.
Powiązania:
https://bibliotekanauki.pl/articles/1031509.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
welding
residual-stresses
HAZ
steel-X70
sinψ²
Opis:
Determination of residual stresses in the welded areas of metal structures is a very important operation in the mechanical construction and other fields, for the reliability and sustainability of these metal structures [J.B. Ju, S.K. Lee, J. Jang, W.S. Kim, D. Kwon, Int. J. Press. Vessels Piping 80, 641 (2003)]. Over the past few years, a significant number of studies have been carried out in order to understand the influence of residual stresses on the assembly by welding, from the standpoint of mechanical properties and corrosion resistance [E. Macherauch, K.H. Kloos, Residual Stresses in Science and Technology, DGM Inform. Verlag, 1987, p. 3; P.J. Withers, H.K.D.H. Bhadeshia, Master Sci. Technol. 17, 366 (2001)]. Several studies have been carried out for the purpose of finding non-destructive methods for the evaluation of the residual stress [H. Nasri, Mesure De Contraintes Résiduelles Dues Au Soudage Et Au Soudage-Martelage Par Micro-Profil De Surface, Ecole De Technologie Supérieure Université Du Québec, 2007; C. Balasingh, A.K. Singh, Metals Materials Proc. 12, 269 (2000)]. One of the methods that proved important, it is that of sinψ². In this work we have applied this method in the assessment of the residual stress in the welded X70 steel.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 866-868
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical parametric study of resistance spot welding process of AISI 1008 steel sheets
Autorzy:
Khabaz-Aghdam, Ata
Rahmani, Azhdar
Fadaei, Abbas
Powiązania:
https://bibliotekanauki.pl/articles/279896.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
resistance spot welding
nugget geometry
residual stresses
simulation
experimentation
Opis:
In the present research, a parametric study in Resistance Spot Welding (RSW) of thin AISI 1008 steel sheets is investigated via FEM. All the time steps through the RSW process, including squeeze time, welding time, holding time and cooling time are taken into account. First, the effects of various parameters such as electrical current, welding time and electrode tip diameter are investigated in the nugget geometry. Then, a time history stress diagram and residual stresses are obtained in RSW weldment. FEM results are validated very well by some experiments which were performed in two parts of nugget geometry and residual stresses.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 4; 807-820
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic analysis of the control stage of a high speed steam turbine
Autorzy:
Sławiński, D.
Zakrzewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/175498.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
control stage
residual stresses
initial displacement blade
vibrations blade
Opis:
This paper analyzes the possibility of resonances within a control stage of a high speed turbine. An original method for steady state operation is used for the analysis of the stiffness matrix representing: initial displacement blade (nominal shape blade obtained by nominal working point of turbine) and residual stresses following local crossing yield plastic strain. In the analysis there has been found a possibility of occurance of the resonance frequency, and mistuning by showing the safe working ranges. The calculation used the 3D modal and harmonic analysis within computational solid dynamics (CSD) and the results were compared with the 0D data from literature. After local crossing of yields stresses, on the basis of the harmonic analysis, there has been shown operation of the blade in the resonance point. Before crossing the yield stresses the blade is working in mistuning and a safe point.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2012, 124; 41-49
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł

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