Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 9
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The usefulness of elastic compliance measurements to estimate crack closure in structural steel and the validity of the assumption of a constant compliance value for the fully open crack is examined. Based on considering different issues related to the experimental technique and compliance data processing, local compliance measurements and the compliance offset method recommended by the ASTM standard are selected to be most suitable for structural steel. The compliance data generated in fatigue tests on I 8G2A steel conducted under a variety of loading conditions enabled to choose an optimal strain gauge positioning and appropriate offset criterion values for the original compliance offset method and its modified (normalized) version. The adequacy of the closure measurements is assessed through checking the ability of the resulting effective stress intensity factors to account for the observed effects of the loading conditions on fatigue crack growth rates.
Go to article

Authors and Affiliations

Małgorzata Skorupa
Andrzej Skorupa
Tomasz Machniewicz
Download PDF Download RIS Download Bibtex

Abstract

The strip yield model from the NASGRO computer software has been applied to predict fatigue crack growth in two different aircraft aluminium alloys under constant amplitude loading and programmed and random variable amplitude load histories. The computation options realized included either of the two different strip yield model implementations available in NASGRO and two types of the input material data description. The model performance has been evaluated based on comparisons between the predicted and observed results. It is concluded that altogether unsatisfactory prediction quality stems from an inadequate constraint factor conception incorporated in the NASGRO models.
Go to article

Authors and Affiliations

Małgorzata Skorupa
Tomasz Machniewicz
Andrzej Skorupa
Download PDF Download RIS Download Bibtex

Abstract

Effects of specimen thickness and stress ratio on fatigue crack growth and crack closure levels under constant amplitude loading and after a single overload have been studied experimentally for a structural steel ( I 8G2A). The corresponding crack growth data from the fatigue tests have been presented and evaluated. The experimental trends have been compared to those reported in the literature for various steels. The ability of the effective stress intensity factor range based on crack closure measurements to correlate the observed crack growth response has been investigated.
Go to article

Authors and Affiliations

Małgorzata Skorupa
Andrzej Skorupa
Jaap Schijve
Tomasz Machniewicz
Paweł Korbut
Download PDF Download RIS Download Bibtex

Abstract

The mutual influence of fatigue processes, abrasive wear and corrosion of chain links on the functional properties of mining round link chains has been presented in this paper. Selected results of experimental investigations in the field of synergic impact of these destructive processes on the operational durability of mining chains have also been presented. The emphasis was given to the necessity of a comprehensive consideration of destructive processes that occur in various conditions of use of round link chains applied in mining machines.
Go to article

Bibliography

[1] www.fasing.pl, accessed: 14.06.2018
[2] E . Remiorz, S. Mikuła, Podstawowe formy degradacji własności użytkowych łańcuchów ogniwowych górniczych stosowanych w maszynach ścianowych. Maszyny Górnicze 35 (3), (2017).
[3] S. Mikuła, Trwałość zmęczeniowa cięgien łańcuchowych górniczych maszyn urabiających i transportowych. Prace Badawcze CMG Komag, Gliwice (1978).
[4] S. Kocańda, Zmęczeniowe niszczenie metali. WNT , Warszawa (1972).
[5] P .M. Wnuk, Pojęcia i zależności w liniowej i nieliniowej mechanice pękania. Eksploatacja i Niezawodność – Maintenance and Reliability 6 (1) (2004).
[6] J. Gubała, E. Zięba, Wykorzystanie mechaniki pękania do określenia wytrzymałości konstrukcji w warunkach oddziaływania korozyjnego. Przegląd Mechaniczny 35 (1) (1976).
[7] K . Kotwica, K. Furmanik, B. Scherf, Wpływ warunków pracy na zużycie i trwałość cięgien łańcuchowych zgrzebłowych przenośników ścianowych w wybranych kopalniach węgla kamiennego. Przegląd Górniczy 67 (11), (2011).
[8] J. Hankus, M. Szot, A. Pytlik, K. Paradowski, Badania łańcuchów ogniwowych górniczych. Materiały Sympozjum Szkoleniowego Europejskiego Studium Menedżerskiego, Jastrzębie Zdrój (2006).
[9] H . Kania, Kształtowanie struktury oraz odporność korozyjna powłoki Zn-Al otrzymanych metodą metalizacji zanurzeniowej. Wydawnictwo Politechniki Śląskiej, Gliwice (2017).
[10] M. Dolipski , E. Remiorz, P. Sobota, J. Osadnik, Komputerowe badania wpływu zużycia den gniazd i flanki zębów bębna na położenie ogniw w gniazdach bębna łańcuchowego. Mechanizacja i Automatyzacja Górnictwa 49 (4), (2011).
[11] M. Dolipski, E. Remiorz, P. Sobota, Determination of dynamic loads of sprocket drum teeth and seats using mathematical model of a scraper conveyor. Arch. Min. Sci. 57 (4), (2012).
[12] M. Dolipski, P. Cheluszka, E. Remiorz, P. Sobota, Innowacyjne górnicze przenośniki zgrzebłowe. Wydawnictwo Politechniki Śląskiej, Gliwice (2017).
[13] A .N. Wieczorek, Influence of Shot Peening on Abrasion Wear in Real Conditions of Ni-Cu-Ausferritic Ductile Iron. Arch Metall. Mater. 61 (4), (2016).
[14] A .N. Wieczorek, Comparative studies on the wear of ADI alloy cast irons as well as selected steels and surfacehardened alloy cast steels in the presence of abrasive. Arch. Metall. Mater. 62 (1), (2017).
[15] S. Mikuła, Ł. Gajda, Metody badań zużycia ściernego łańcuchów górniczych. Zeszyty Naukowe Politechniki Śląskiej, s. Górnictwo 93 (1978).
[16] E . Remiorz, S. Mikuła, Diagnosis of round link chains resistance to abrasive wear. Technicka Diagnostika 27 (1), (2018).
[17] B . Pawlukiewicz, J. Wiederman, Mechanizm niszczenia ogniw łańcuchów górniczych podczas eksploatacji. Inżynieria Materiałowa 19 (5), (1998).
[18] E . Remiorz, S. Mikuła, Eksploatacyjna diagnostyka ogniwowych łańcuchów górniczych stosowanych w pociągowych układach łańcuchowych maszyn ścianowych. Maszyny Górnicze 36 (1), (2018).
Go to article

Authors and Affiliations

Eryk Remiorz
1
ORCID: ORCID
Stanisław Mikuła
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Mining, Safety Engineering and Industrial Automation, Department of Mining Mechanization and Robotisation, 2 Akademicka Str., 44-100 Gliwice, Poland
Download PDF Download RIS Download Bibtex

Abstract

The paper presents kinetic fatigue crack growth curve for IOHNAP steel, which is verified experimentally. An energy approach based on the M-integral range is shown. The tests have been carried out on plane specimens With notches under tension-compression for three values of stress ratio R. The J-integral is calculated analytically and by the finite element method. A relationship for the description of the whole kinetic crack growth curve including J-integral is presented. It is shown that at the constant loading and the change of stress ratio R from - 1 to O the fatigue crack growth rate increases. A relationship is proposed in the paper for description of the kinetic crack growth curve. It gives results that are consistent with experimental ones and those obtained with the use of the finite element method (FEM).
Go to article

Authors and Affiliations

Dariusz Rozumek
Download PDF Download RIS Download Bibtex

Abstract

Recently, the need to develop fuel efficient transport systems has led to the development of a range of materials of low density, high stiffness and high strength each can be made at a reasonable cost. The aluminium based alloys are particularly important because of their improved mechanical, physical and technical properties. Fatigue failures have been recognised since the early days of the industrial revolution. Fatigue response of most of materials is related with the microstructural variations in the structure. Hence, in this study, influence of particle size and volume fractions on fatigue properties of Al-alloy composites was investigated. It was found that particle size and volume fraction of reinforcement particles play significant role on fatigue propagation rates, stress intensity threshold values, crack tip opening distance and crack tip plastic zone sizes.
Go to article

Authors and Affiliations

I. Uygur
1
ORCID: ORCID

  1. Duzce University, Faculty of Engineering, Department of Mechanical Eng. 81620, Duzce
Download PDF Download RIS Download Bibtex

Abstract

In the present paper, the excavation of the energetic approach that estimates the fatigue crack initiation life of metal is conducted for H62 brass. The benefit of the energetic approach is the division of the actual applied strain range Δε into two parts, that is, a damage strain range Δεd that induces fatigue damage within the metal, and an undamaged strain range Δεc, which does not produce fatigue damage of the metal and corresponds to theoretical strain fatigue limit. The brightness of this approach is that the undamaged strain range Δεc can be estimated by the fundamental conventional parameters of metal in tensile test. The result indicated that the fatigue crack initiation life of H62 brass can be estimated by this approach successfully.
Go to article

Authors and Affiliations

M. Zheng
1
ORCID: ORCID
S. Zhang
1
ORCID: ORCID
X.J. Peng
1
ORCID: ORCID
Y. Wang
1
ORCID: ORCID

  1. Northwest University, School of Chemical Engineering, Xi’an 710069, P. R. China
Download PDF Download RIS Download Bibtex

Abstract

The paper presents the results of tests on fatigue crack growth under bending in an elastic-plastic material. Specimens with rectangular sections and stress concentrator in the form of external one-sided sharp notch were used. The tests were performed under the stress ratios R = - I, - 0.5, O. The test results were described by the /'i ]-integral range and compared with the /'i K stress intensity factor range. It has been found that there is a good agreement between the test results and the empirical formula of fatigue crack growth rate, which includes the /'i ]-integral range.
Go to article

Authors and Affiliations

Dariusz Rozumek
Download PDF Download RIS Download Bibtex

Abstract

Fatigue crack growth for 2024-T3 Alclad aluminium alloy sheet being subjected to two load programs: a constant stress amplitude cyclic tension (R=O. l) (CA) and a variable amplitude tension with either a single or multiple overloads (OVL) periodically repeated is analysed in the paper. The latter load program corresponds to a simple flight simulation spectrum of wing structure of civil aircraft. The investigation was developed in order to learn about interaction between the applied load and formation of fatigue striations. Experimental results of surface crack growth rate provided by optical observations were compared with the rate determined on the basis of microfracture analysis. Good correspondence found under CA loading between the surface growth rate and the growth rate in the sheet depth means that the direction of specimen's cutting does not change essentially the crack growth behaviour. In the case of second loading (OVL) this factor influences the crack growth behaviour. Microfracture analysis revealed either retardation and acceleration of crack growth rate under OL V loading. This behaviour of growth rate results from a plastic zone formed in the front of crack tip and a crack closure effect.
Go to article

Authors and Affiliations

Dorota Kocańda
Stanisław Kocańda
Janusz Torzewski

This page uses 'cookies'. Learn more