Wyniki wyszukiwania - BazTech

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Wpływ warunków pogodowych na drgania generowane przez pojazdy kołowe

Honkisz M.

Autobusy : technika, eksploatacja, systemy transportowe

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2017

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R. 18, nr 12

149--153, CD

PL

Celem badań opisanych w niniejszym artykule jest przeprowadzenie eksperymentów mających na celu określenie wpływu wybranych warunków pogodowych na postać generowanych przez pojazdy kołowe drgań. Dotychczas zdobyta wiedza pozwala na przypuszczenie, że do tej pory nie prowadzono badań pozwalających na określenie takiego wpływu. Co więcej, czynniki atmosferyczne nigdy nie były brane pod uwagę jako czynnik mający wpływ na rozprzestrzenianie się oraz kształt drgań. Analiza otrzymanych wyników powinna pozwolić na sformułowanie zaleceń odnośnie konieczności uwzględniania zmian tych parametrów w praktycznych zastosowaniach.

EN

The purpose of the research described in this article is to carry out experiments for determine the impact of selected weather conditions on the form of vibrsation coused by different vehicles. Previous research suggests that so far no research has tested such influence. Moreover, atmospheric factors have never been considered as a factor influencing the spread and shape of the vibrations. Analysis of the results obtained should allow for recommendations on the need to include changes in these parameters in practical applications.

2

Investigation of Dynamics and Control of the Single-Wheel Vehicle

Sanh D., Dihn V. P., Do D. K., Tran D.

Machine Dynamics Problems

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2007

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Vol. 31, No. 4

46-56

EN

In the presented paper, the problem of controlling a one-wheel vehicle is investigated. In connection with this problem, a hybrid method of both passive and active methods is applied. By means of the motion of an elliptic pendulum (passive controls) and the couple of forces of a servomotor (active controls) the unbalanced motion of the vehicle is controlled. The stated problem is solved by the theory of optimization of Hamilton and the method of constructing program constraints. A numerical algorithm is introduced, which is generalized for optimal problems of mechanical systems in the sense of stabilization.

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Modelling and Analysis of Wave Propagation in Railway Wheel Rims

Kocjan M., Bogacz R., Kurnik W.

Machine Dynamics Problems

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2006

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Vol. 30, No. 1

33-42

EN

The paper is concerned with railroad wheel rim behavior under concentrated transverse contact forces. Design of underframe elements of modern high-speed railway vehicles requires detailed understanding of the behaviour of wheelsets, especially wave propagation in wheel rims, responsible for noise emitted, wear, corrugation, wheel poligonalisation etc. (Bogacz, 1995). In the present study, a wheel rim is treated as a curved beam of various beam models like curved Bernoulli-Euler beam, curved Rayleigh beam and curved Timoshenko beam (Bogacz, Kocjan, Kurnik 2003). They are compared with the Mahrenholtz approach based on the straight beam theory (Mahrenholtz, 2000). The influence of wheel radius on transverse wave propagation in the rim is studied. The wheel plate is modelled as a viscoelastic Winkler-type foundation (Bogacz, Dżuła, 1998). Travelling waves are analyzed with special attention paid to the velocity of propagation. The beam equations are solved using Fourier transformation, and the results are presented in form of time-space graphs. The effect of the vehicle speed is studied as well. The results obtained indicate important criteria to be taken into account in design of modern high-speed railroad wheelsets and bogies. It is shown that in general curved beam theory should be applied, but under some particular conditions the straight beam model is accurate enough. The influence of the internal stresses combined with wheel plate stiffness on wave propagation is presented as well.