PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 8

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  bolts
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available The Fibrous Structure of the Bolt and Its Effect on the Joint Reliability
Dubiel Tomasz, Balawender Tadeusz, Osetek Mirosław
Archives of Metallurgy and Materials
|
2021
|
Vol. 66, iss. 4
1075--1085
EN
The use of cold forging is a widely used solution in many industries. One application is the manufacture of bolts and fasteners. The largest amounts of bolts are used in the automotive and machine industry. Those customers demand high standards of quality and reliability from producers based on ISO 9001 and IATF 16949. Also, the construction, agriculture and furniture industries are raising their expectations for deliveries from year to year. Automotive companies issue their standards specifying specific requirements for products. One of these standards is the aviation standard SAE USCAR 8-4; 2019, which speaks of a compatible arrangement of fibers in the bolt head and in the area of transition into the mandrel. The article presents the cold forging process of flange bolts. Obtaining a compatible, acceptable and incompatible grain flow pattern based of the above mantioned standard was presented. Then the results of FEM simulation were correlated with the performed experiment. The effect of incompatible grain flow system was discussed and presented as the crack initiating factor due to delta ferrite, hydrogen embrittlement, tempering embrittlement. The reliability of the connections was confirmed in the assembly test for yield stress on a schatz machine. The advantages of this method and the difference compared to the tensile test were presented.
2
Content available remote Preferred diameters in series of fasteners
Jasińska Anna, Sydor Maciej
Fastener : rynek elementów złącznych
|
2020
|
nr 2
51--54
EN
Reducing the variety of elements of a structure of different products is beneficial at all stages of their functioning: from design, through manufacturing, use, maintenance and disposal. For this purpose, type series of standardised products, forming arithmetic and geometric sequences, as well as modular ordering, are generally used in industrial design. The main way to reduce the diversity of machine parts in a particular series of fasteners is to select its preferred elements. A good example of this approach is the preference of bolt sizes: M6, M10, M16, M24 from a fragment of series comprising: M6, M7, M8, M10, M12, M14, M16, M18, M20, M22 and M24 bolts.
3
Content available An Impact of Assembly Interference on Stresses in the Die Tool System During Bolt Forging
Nowotyńska I., Kut S., Osetek M.
Archives of Metallurgy and Materials
|
2019
|
Vol. 64, iss. 4
1471--1478
EN
The article presents an analysis of stresses in the current tool system of the die during the implementation of the third forging operation of the screw M12 class 10.9 with cylinder head and hexagonal socket. It was assumed that the level of negative cracking due to stress can be reduced by using a mounting interference between the die and the tube blank. Due to the design of the tool system value of the die, the interference value cannot be too large. Therefore, an analysis of the influence of the interference between the die and the tube blank in a die tool system on the value and distribution of stresses in the individual components. An analysis of the assembly stresses and the stresses occurring during the process of deformation of the shaped head of the screw was done. The calculations were performed using a commercial software package MARC / Mentat.
4
Content available remote Materials used for the production of bolts and nuts – part II. Fasteners made of steels other than stainless steel
Gremza G.
Fastener : rynek elementów złącznych
|
2018
|
nr 1
71--74
EN
Properties of stainless steels used for the production of bolt and nut assemblies were discussed in the paper [1] along with performance characteristics of these assemblies. In this part, properties and scope of application of bolts and nuts made of steels other than stainless steel are presented. Various fasteners made of non-ferrous metals and plastics shall be discussed in a separate paper.
5
Content available Damage Analysis of the Blade to the Rotor Hub Connection in the Wind Turbine
Gremza G., Zamorowski J.
Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture
|
2018
|
z. 65, nr 2
55--67
EN
The paper analyzes possible causes of bolts fracture in the connection of the blade to the hub of the wind turbine rotor. This failure has been growth shortly after the wind turbine was started, a few days after the storm. During the storm, electric power was turned off in the whole surrounding area for many hours, therefore it was impossible to control the device. After an initial analysis of failure modes in other wind turbines, it was found, that the bolts failure in the analysed case may be regarded as quite rare. Due to the fact that a significant part of bolts was broken brittle (flat fracture surfaces and lack of permanent elongation), it was decided to analyse the structure of the material in the direction of stress corrosion and hydrogen embrittlement. Among others, microscope analysis of fracture surfaces after their proper cleaning from corrosion products was carried out. The broken bolts were made as undersized, what is mainly used in fasteners intended for hot-dip galvanizing. On the basis of the purchase documentation analysis, it was presumed that the bolts were not galvanized by their manufacturer, which is obliged to perform the routine inspection in production process preventing the introduction of the hydrogenated bolts into the market. Besides the bolts examination, the scenarios of connection loads in extreme situations, in particular the impact of wind with high energy in the most unfavourable direction relative to the blade and nacelle, as well as the force resulting from the impact of the rotating blade on the tower that preceded the collapse of the whole structure, were considered. Conclusions from the performed tests and calculations by use of two calculation models of the connection were presented.
6
Content available remote Preventing head cracks on bolts: a numerical approach
Yavuzbarut T., Kılıçaslan C.
Fastener : rynek elementów złącznych
|
2017
|
nr 2
86--87
EN
Cold forging, one of the oldest methods of production, is a metal forming process that is often preferred in today’s industry. In cold forging process, workpiece is formed by being exposed to press forces between two dies or tools. Moreover, high surface quality can be obtained and precise tolerances can be achieved in cold forging.
7
Content available Łączniki w konstrukcjach zespolonych stalowo-betonowych : przegląd rozwiązań
Major M., Kuliński K.
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
|
2015
|
Z. 21 (171)
205--210
PL
W artykule zaprezentowano historyczne i współczesne stosowane rozwiązania połączeń w konstrukcjach zespolonych stalowo-betonowych. Dodatkowo w pracy omówiono wymagania, jakie współcześnie muszą spełniać łączniki mechaniczne.
EN
In this paper there were shown historical and present utilized solutions of connections in composite steel-concrete structures. Moreover, current requirements for bolts in accordance with European Eurocode have been presented.
8
Computational and experimental analysis of the bolt head trimming process
Petruska J., Borkovec J.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
2005
|
z. 28
121-124
EN
Bolt head trimming is a fast, complicated cutting process including material failure. For this reason, explicit solver LS-Dyna was used for its simulation. The aim of the simulation was to minimize the loading of the trimming matrix, so that its durability could be enhanced. Three geometrical versions were solved and the results were compared with respect to the cutting work and contact force. As the reliability of the computational model can be questionable, an experiment was carried out to verify the computational results. Cutting force, shape of trimmed areas and distribution of plastic deformation and shear bands were compared with the computational results.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.