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1

The influence of thermomechanical coupling on the behaviour of athick-walled metallic tube subjected to internal pressure

Śloderbach Z.

International Journal of Applied Mechanics and Engineering

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2018

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Vol. 23, no. 3

751--766

EN

In this study, the influence of thermomechanical coupling effect - the effect of thermal expansion due to dissipation of the energy of plastic deformation, with and without taking into account the stored energy of plastic deformation (SEPD) for the distribution of stresses, strains, temperature, the applied pressure and the residual stresses is examined. The residual stresses remain in a thick-walled tube (a cylindrical thick-walled tank) after removing the internal pressure in the process of purely elastic unloading. The analysis is made on the example of an analitycal solution for a thick-walled tube subjected to a quasistatically increasing internal pressure for the case of adiabatic processes (without heat flow). Since the loading with internal pressure is quasi-static (monotonic), then neglecting the process of heat flow can lead to some different results in calculated stresses, deformations, temperature, internal pressure and residual stresses. The calculations for isothermal type of processes of deformations (without heat or ideal cooling) are also performed for the estimation of these differences. The results calculated for the process with heat flow should be intermediate between the values obtained for isothermal and adiabatic processes.

2

Explorative study of rotary tube piercing process for producing titanium alloy thick-walled tubes with bi-modal microstructure

Zhang Z., Liu D., Yang Y., Pang Y., Wang J., Wang H.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 4

1451--1463

EN

In order to solve the existing problems in the manufacturing of titanium alloy thick-walled tubes (TATWs), an innovative plastic forming method for the preparation of TATWs using rotary tube piercing (RTP) process was studied. In this paper, the advantages and basic principles of the RTP process were described. A new finite element model is established to study the effect of the thermal parameters on the RTP process of TATWs. Based on the control variable method, two key problems of rolling block and severe temperature rise in the RTP process were all solved, and the TATWs with bi-modal microstructure were produced by the self-developed piercing mill. In addition, the microstructure uniformity of the pierced tube was analyzed. Based on the experimental and numerical investigations, it's found that the RTP process is a viable process for manufacturing TATWs with bi-modal microstructure.

3

Nośność i wytężenie osiowo ściskanych polimerowych rur grubościennych wypełnionych betonem

Abramski M., Korzeniowski P., Wesołowski M.

Inżynieria i Budownictwo

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2014

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R. 70, nr 5

280--284

PL

Przedstawiono wyniki badań i porównano je z podobnymi badaniami polimerowych rur cienkościennych. Stwierdzono, że grubość płaszcza w znacznym stopniu wpływa na zachowanie pokrytyczne słupów oraz rozwój odkształceń podłużnych i obwodowych płaszcza w trakcie procesu obciążania. Próbę wykorzystania zaczerpniętej z Eurokodu 4 procedury obliczania stalowo-betonowych słupów zespolonych do wyznaczania nośności badanych słupów uznano za nieudaną.

EN

In the paper results of experimental investigation carried out on axially loaded polymer thick-walled tubes filled out with concrete are discussed. Comparing this investigation with other tests carried out on similar, but thin-walled tubes authors realize significant differences in post-critical behavior as well as strain development in tube in both longitudinal and circumferential directions. A trial of adaptation of Eurocode 4 procedure of calculating composite steel-concrete columns for the tested columns was made. However load-carrying capacities obtained using this approach differ from the experimental results in authors’ opinion too much.