Temat: riveted joints - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Analysis of the Quasi-Static Riveting Process for 90° Countersunk Rivet
Autorzy:: Kaniowski, J.
Wronicz, W.
Tematy:: aircrafts
riveted joints
fatigue damage; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Powiązania:: https://bibliotekanauki.pl/articles/97753.pdf Link otwiera się w nowym oknie
Opis:: Riveting is the most commonly used method of joining sheet metal components of the aircraft structure. The riveted joints are critical areas of the aircraft structure due to severe stress concentrations and effects such as fretting and secondary bending. The most spectacular and wellknown evident of this was the accident of Boeing B737 of Aloha Airline in 1988, when during the flight at altitude of 7300 m a large part of fuselage skin was removed due to explosive decompression. The investigation showed that the reason for this accident was widespread fatigue damage of riveted joints. This accident was an impulse for establishing many research programs around the world focused on fatigue of riveted joints.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Numerical study of the influence of shape imperfections on residual stress fields in a rivet hole
Autorzy:: Sławiński, G.
Niezgoda, T.
Szymczyk, E.
Jachimowicz, J.
Tematy:: FEM
riveted joints
imperfections
residual stress; Pokaż więcej
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Powiązania:: https://bibliotekanauki.pl/articles/246398.pdf Link otwiera się w nowym oknie
Opis:: The paper deals with the numerical analysis on residua! stress and strain fields in a rivet hole. This stage of study concerns improving of the fatigue performance of riveted joints in an airframe. Riveting, particularly in aviation, is a traditional but still commonly used method of joining sheet metal components. Aircraft structures are thin-walled ones, with coverings made of thin sheets stiffened by stringers, frames or ribs. Sheets are typically assembled by a multiple rivet or bolt joints. Rivets and bolts are also used to joint sheets and stiffeners. Therefore, fatigue resistance of the aircraft structure depends on tens of thousands or even hundreds of thousands r ivet joints, which are used to build it. The local numerical models of the joint are considered with regard to the aim introduced in the paper. Numerical FE simulations of an upsetting process are carried out using the LS-DYNA code. Three-dimensional numerical models are used to determine the resulting stress and strain fields at the mushroom rivet and around the hole. This type of problem requires the use of contact between the elements assembled and non-linear geometrie and elasto-plastic multilinear materiał models to simulate the behaviour of the rivet and sheets. The influence of shape imperfection on strain and stress states is studied.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: The Synthetic Description of the Results, Scientific Achievements and Practical Applications of the Eureka − Imperja Project, E3496! − “Improving the Fatigue Performance of Riveted Joints in Airframes”
Autorzy:: Kaniowski, J.
Tematy:: riveted joints
fatigue life estimation
aircrafts; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Powiązania:: https://bibliotekanauki.pl/articles/97887.pdf Link otwiera się w nowym oknie
Opis:: The goal of the project was to increase the fatigue life of the riveted joints in order to achieve an increase in the aircraft service life, a smaller number of inspections and, consequently, lower aircraft operating costs. This goal was achieved by the analysis and optimization of the riveting process as well as by improving the fatigue life prediction methods (crack initiation and propagation). The project outcomes enable a more precise fatigue life estimation and an increase in Time Before Overhaul (TBO) for currently used aircraft, as well as optimize the design of new aircraft from the fatigue point of view.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: X-Ray Diffraction Measurements for Riveted Joints. The Application of a Novel Methodology
Autorzy:: Gadalińska, E.
Kaniowski, J.
Tematy:: X-ray diffraction method
stress measurements
riveted joints; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Powiązania:: https://bibliotekanauki.pl/articles/97767.pdf Link otwiera się w nowym oknie
Opis:: The X-ray diffraction method is the best, widely available, non-destructive measurement method used to determine the residual and load stresses in crystalline materials. This method can be applied without any limitations to flat specimens. Depending on the equipment geometry, the type of material and geometry of the specimen, there are many limitations, restrictions and recommendations which have to be fulfilled to obtain reliable results. This was the reason for working out a methodology for X-ray diffraction stress measurements for riveted specimens.The first case to analyze is the necessity of choosing an X-ray tube suitable for the specimen material which will give the diffraction peaks in the range of 2Θ angles between 120° and 180°. Afterwards it is crucial to make the best selection of Bragg's angle 2Θ. In the vast majority of cases the best selection is the possibly biggest 2Θ angle because of the best accuracy of the measurement. However, for example for aluminum alloys (for Cr_{K_α} radiation), this choice is not so obvious. It is much more convenient to perform measurements not for the highest diffraction angle. The best selection in this case is 2Θ=139,3°, and not 156,7°. Other selections which are necessary to be made before measurements are the collimator diameter, time of exposure, ψ tilts and φ oscillations. The proper selection of these parameters is crucial for the fast and efficient performing of measurements and for obtaining reliable results. Before performing the measurement, especially in the case of the specimen with complicated geometry (for example in the case of riveted specimens made of aluminum alloys), it is necessary to analyze the results obtained paying special attention to the possibility of the appearing of the rivet head/driven rivet head shadow during the measurement. The work describes differences between the X-ray stress measurement results obtained without any interference and the results received after eliminating the selected diffraction peaks for which the shadow of rivet head/driven rivet head has appeared.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Numerical Analysis of Material and Manufacturing Factors in Riveted Joints Under the Imperja Project
Autorzy:: Szymczyk, E.
Bogusz, P.
Sławiński, G.
Jachimowicz, J.
Tematy:: riveted joints
fatigue strength
optical methods
SEM analysis; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Powiązania:: https://bibliotekanauki.pl/articles/97935.pdf Link otwiera się w nowym oknie
Opis:: The aim of the project was to improve fatigue performance of riveted joints in airframes. Fatigue strength of a joint depends on structural, material and manufacturing factors. The project involved numerical and experimental analysis of material factors and manufacturing imperfections. The paper deals with the analysis of material structure and properties by means of the optical and SE methods. Static monotonic tests for sheet and rivet materials were carried out. ARAMIS optical system was used for the study of deformation and strain fields in the material during loading. This tool offers the possibility of a non-contact measurement with 3D image correlation methods (digital image correlation, DIC) using high-resolution digital CCD cameras. In ductile materials (such as aluminium alloy), subjected to appropriate loading conditions, voids may form, which grow and coalesce leading to crack formation and potential failure. A micro crack may be initiated at the inclusion particles and then voids grow around it. Experimental studies showed that these processes are strongly influenced by hydrostatic stress (Gurson’s material model). SEM analysis of material structure was carried out after performing static tests. In the paper, the authors present the influence of a material model on the results of numerical simulation of the tensile loaded samples with open and riveted holes. The application of Gurson’s material model allows observation of crack growth in the sample cross-section and determination of the sheet rupture as the moment when constraint force decreases to zero (material separation occurs).
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Comparison of Selected Rivet and Riveting Instructions
Autorzy:: Kaniowski, J.
Tematy:: riveted joints
rivets
riveting parameters
riveting instructions and standards; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Powiązania:: https://bibliotekanauki.pl/articles/97986.pdf Link otwiera się w nowym oknie
Opis:: Sheet metal parts are widely used in airframes. Most sheet metal parts used in aircraft assembly are joined using rivets. A number of riveting parameters directly influence fatigue properties of a structure. These include a rivet length, driven head diameter, tolerance of a rivet hole and a rivet shank diameter, and a protective layer among others. Unfavourable selection or change of these parameters can lead to stress concentrations and early crack nucleation. Crack growth can cause failure of a whole structure. The selection of the riveting process parameters is usually described in a company’s internal instruction (process specifications). Some parameters can be defined in an aircraft's technical specifications. Riveting instructions among other production documentation are part of a company's closely guarded know-how. The author obtained access to two riveting instructions used in Poland and three such documents used in western Europe. The author was permitted to publish the comparison of the parameters from these documents but he is not supposed to reveal any other information. For the reasons stated above, the following cryptonyms were used in the article: Poland-1, Poland-2, West-1, West-2 and West-3. The quality of a joint also depends on rivets parameters that are defined in rivets standards. For this reason, selected rivets defined in the Polish and Russian industry standards as well as western standards are compared in this paper. Tolerances of a rivet and a hole diameter, clearances between a rivet and a hole, rivet lengths anticipated for driven head formation as well as driven head dimensions are taken into account.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Numeric simulations of surface pressure and microslip phenomena occurring in riveted joints of semi-monococque structures in effect of the action of tension field
Autorzy:: Mańkowski, J.
Tematy:: riveted joints
micro-slips
thin-walled structure
semi-monococque; Pokaż więcej
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:: https://bibliotekanauki.pl/articles/132156.pdf Link otwiera się w nowym oknie
Opis:: Tension fields are shown to have an influence on surface pressure and on material deformation in the riveted joints in thin walled structures and particularly in semistressed skin structures. Stresses and materials displacements were analyzed in the riveted joints performing under such conditions. Special attention has been attached to estimation of the microslips occurring between rivets and holes. A thin plate panel has been used for the test sample, which under effort condition revealed tension fields.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Improvement of fatigue life of riveted joints in helicopter airframes
Autorzy:: Rośkowicz, Marek
Godzimirski, Jan
Jasztal, Michał
Gąsior, Jarosław
Tematy:: riveted joints
hybrid joint
fatigue life
titanium driven blind bolts with pin
ordinary mushroom head rivets; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:: https://bibliotekanauki.pl/articles/1841763.pdf Link otwiera się w nowym oknie
Opis:: Using original cold-formed rivets in repairs of airframes of helicopters is difficult due to no access to inside parts of the airframe. Thus, the main aim of the study was to investigate the possibility to use the blind rivets or hybrid joints by verification the fatigue performance of such joints that must be better than with original rivets. Riveted and hybrid joints have been experimentally tested under static and fatigue loads. Furthermore, numerical calculations of stress distribution for strapped joint have been conducted. The test results covered fatigue life of lap joints and models of repaired airframe sheets using ordinary mushroom head rivets ref. 3558A-4-10, titanium driven blind bolts with pin, ref. MBF2110AB-05-150 and modified hybrid joints. Using titanium driven blind bolts with pin instead of ordinary hammer-bucked rivets, can improve the fatigue life of element made of aluminum alloy AW 2024T3. There are advantages of replacing riveted joints with modified hybrid (rivet & adhesive) joints in threefold increase in fatigue life of repaired airframe structures.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Improvement of fatigue life of riveted joints in helicopter airframes
Autorzy:: Rośkowicz, Marek
Godzimirski, Jan
Jasztal, Michał
Gąsior, Jarosław
Tematy:: riveted joints
hybrid joint
fatigue life
titanium driven blind bolts with pin
ordinary mushroom head rivets; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:: https://bibliotekanauki.pl/articles/1841792.pdf Link otwiera się w nowym oknie
Opis:: Using original cold-formed rivets in repairs of airframes of helicopters is difficult due to no access to inside parts of the airframe. Thus, the main aim of the study was to investigate the possibility to use the blind rivets or hybrid joints by verification the fatigue performance of such joints that must be better than with original rivets. Riveted and hybrid joints have been experimentally tested under static and fatigue loads. Furthermore, numerical calculations of stress distribution for strapped joint have been conducted. The test results covered fatigue life of lap joints and models of repaired airframe sheets using ordinary mushroom head rivets ref. 3558A-4-10, titanium driven blind bolts with pin, ref. MBF2110AB-05-150 and modified hybrid joints. Using titanium driven blind bolts with pin instead of ordinary hammer-bucked rivets, can improve the fatigue life of element made of aluminum alloy AW 2024T3. There are advantages of replacing riveted joints with modified hybrid (rivet & adhesive) joints in threefold increase in fatigue life of repaired airframe structures.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Observations on fatigue crack growth and fatigue life of riveted lap joints
Badania rozwoju pęknięć i trwałości zmęczeniowej w zakładkowych połączeniach nitowych
Autorzy:: Skorupa, A.
Skorupa, M.
Machniewicz, T.
Korbel, A.
Tematy:: riveted joints
fatigue life
crack initiation
fatigue crack growth
połączenia nitowe
trwałość zmęczeniowa
inicjacja pęknięć
rozwój pęknięć zmęczeniowych; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/368973.pdf Link otwiera się w nowym oknie
Opis:: Effects of variables related to design and production of riveted lap joints representative of longitudinal sheet connections for a pressurized transport aircraft fuselage were experimentally investigated. The specimens from an aircraft Al alloy D16 Alclad sheets of three different thicknesses (1.9, 1.2 and 0.8 mm) were assembled under load control using round head rivets and rivets with the compensator from a P24 Al alloy. For the joints from 1.9 mm thick sheets fatigue tests indicated a dependency of the crack initiation site and crack path on the squeeze force level and on the rivet type. At the same time, increasing the squeeze force led to improved fatigue properties of the joints, specimens assembled using the rivets with the compensator showing fatigue lives consistently longer than joints with the round head rivets. All observed trends have been explained based on hole expansion and load transfer measurements. For thin sheets connected using the round head rivets, local deformations and indentations under the driven rivet head promoted crack initiation and failure in the adjacent sheet. Fatigue test results indicated that the detrimental effect of this type imperfections could outweigh the benefits associated with a decrease in secondary bending due to thinning the sheets. The rivets with the compensator were observed to cause significant local imperfections beneath the manufactured head, which adversely affected the joint fatigue performance.
Sposób zniszczenia i wytrzymałość zmęczeniowa połączeń zakładkowych stosowanych w lotnictwie zależy od wielu czynników technologicznych i konstrukcyjnych, a w szczególności od rodzaju nitu i siły jego zakuwania oraz grubości łączonych blach. W artykule omówiono te zagadnienia na przykładzie blach o różnych grubościach z lotniczego stopu aluminium D16, połączonych zakładkowo za pomocą nitów z łbem kulistym ze stopu PA24. Próbki połączeń poddawane były stałoamplitudowym obciążeniom zmęczeniowym przy różnych poziomach naprężeń nominalnych. Wykazano, że wraz ze wzrostem siły zakuwania nitów rośnie trwałość zmęczeniowa połączenia, a tor pęknięcia oddala się od przekroju netto blachy. Zaobserwowano, że pęknięcia zmęczeniowe pojawiają się w blasze, w której ekspansja otworów nitowych jest mniejsza, co z kolei zależy od rodzaju nitu. Trendy te wyjaśniono na podstawie wyników pomiarów ekspansji otworów nitowych wypełnionych nitami zakutymi przy użyciu różnych sił oraz z uwzględnieniem wyznaczonego eksperymentalnie względnego udziału poszczególnych rzędów nitów w transferze obciążenia. Stwierdzono, że nity z kompensatorem nie są odpowiednie do łączenia cienkich blach; w trakcie zakuwania powstają znaczne deformacje złącza obniżające jego własności zmęczeniowe.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "riveted joints" wg kryterium: Temat