Wyniki wyszukiwania - BazTech

1

Fatigue characteristics of 6082-T6 aluminium alloy obtained in tension-compression and oscillatory bending tests

Kurek A., Kurek M., Koziarska J., Vantadori S., Łagoda T.

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

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2018

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no. 3

57--69

EN

The paper presents the comparison of the results of experimental fatigue tests for 6082-T6 aluminium alloy, carried out for two states of loading: strain controlled tension-compression, and strain and bending moment controlled oscillatory bending. The following were used for that purpose: the Manson-Coffin-Basquin, Kandil, Langer, and the authors’ own strain fatigue characteristics, and also the Basquin stress fatigue characteristic. Our experimental studies and adequate physical relationships were applied to convert the amplitudes of stress and strain occurring in rods without a geometrical notch subject to bending, according to the model of an elasto-plastic body. The obtained results were used to compare both loading types under different control methods and different fatigue characteristics.

PL

W pracy przedstawiono porównanie wyników eksperymentalnych prób zmęczeniowych dla stopu aluminium 6082-T6, przeprowadzonych dla dwóch stanów obciążenia: rozciąganie-ściskanie i ściskania oraz zginania oscylacyjnego kontrolowanego pod wpływem odkształcenia i zginania. Do tego celu użyto następujących parametrów: odkształceniowej charakterystyki zmęczeniowej Mansona-Coffina-Basquina, Kandila, Langera i autorów, a także naprężeniowej charakterystyki zmęczeniowej Basquina. Własne badania eksperymentalne i odpowiednie związki fizyczne zostały zastosowane do konwersji amplitud naprężenia i odkształcenia występującego w elementach zginanych bez karbu geometrycznego, zgodnie z modelem ciała sprężysto-plastycznego. Uzyskane wyniki wykorzystano do porównania obu typów obciążeń przy różnych metodach sterowania i różnych charakterystyk zmęczeniowych.

2

Mechanical behaviour and phase transition mechanisms of a shape memory alloy by means of a novel analytical model

Carpinteri A., Di Cocco V., Fortese G., Ronchei C., Scorza D., Vantadori S., Zanichelli A., Iacoviello F., Natali S.

Acta Mechanica et Automatica

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2018

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Vol. 12, no. 2

105--108

EN

The aim of the present paper is to examine both the fatigue behaviour and the phase transition mechanisms of an equiatomic pseudo-elastic NiTi Shape Memory Alloy through cyclic tests (up to 100 loading cycles). More precisely, miniaturised dog-bone specimens are tested by using a customised testing machine and the contents of both austenite and martensite phase are experimentally measured by means of X-Ray diffraction (XRD) analyses. On the basis of such experimental results in terms of martensite content, an analytical model is here formulated to correlate the stress-strain relationship to the phase transition mechanisms. Finally, a validation of the present model by means of experimental data pertaining the stress-strain relationship is performed.

3

Fatigue Crack Propagation in Notched and Unnotched Round Bars

Carpinteri A., Vantadori S.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2005

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z. 79

53-64

4

Critical plane approach for multiaxial fatigue of metals

Carpinteri A., Spagnoli A., Vantadori S.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2001

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z. 67

47-66

EN

Some common fatigue criteria applicable to generic plane stress states under sinusoidal loading are reviewed with emphasis to those based on the so-called critical plane approach. Then a multiaxial high-cycle fatigue criterion recently proposed by the authors and based on the critical plane approach is discussed. Such a criterion can be applied to the case of sinusoidal plane stress states, and an extension to random loading is presented. According to this criterion, the critical plane orientation is correlated with the averaged principal stress directions deduced through the weight function method. Then the fatigue failure assessment is performed by considering a nonlinear combination of the maximum normal stress and the shear stress amplitude acting on the critical plane. Finally, relevant experimental tests on brittle (hard) metals, related to sinusoidal as well as random plane stress states, are analysed by applying the proposed criterion, together with other common critical plane criteria.