Wyniki wyszukiwania - BazTech

1

An assessment of trailer suspension dynamic behavior via vibration measurements

Hunicz J., Koszałka G., Golec M., Taratuta L.

Journal of KONES

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2012

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Vol. 19, No. 4

333-338

EN

A dynamic response of a semi-trailer suspension to a real road profile under two different loads was investigated in this study. The trailer was a low loader for transporting heavy and large loads which configuration could be adjusted to the current needs. During the described investigation the vehicle was composed of: detachable gooseneck, maximally extended low bed and 5 hydraulically steered axles comprised 2-axle and 3-axle assemblies. The experiments were performed for unloaded and loaded with 60 tons trailer, that was equal to maximum trailer pay load. Acceleration measurements at unsprung and sprung parts of the vehicle were applied. As a test surface a railway track crossing was chosen. Acceleration time series were analysed by the means of power spectral density. The isolation of free vibration and forced vibration frequencies and effectiveness of suspension damping over wide frequency range was done. Two characteristic signal bands were identified. In the frequency range up to 10 Hz vehicle vibration energy decreased for the load increase for both, sprung and unsprung parts. In contrast, in the range between 10 and 25 Hz at higher load increase of vibration energy was noticed, however only at unsprung mass. Data analysis revealed complexity of vehicle vertical acceleration as a response to the road profile. Nevertheless, it allowed for estimation of the trailer dynamic loads under real road conditions.

2

Experimental determination of suspension magnitude-frequency responses using electro-hydraulic actuators - testing and data processing methods

Ślaski G.

Archiwum Motoryzacji

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2012

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Nr 2

63-75

EN

The paper presents the use of magnitude-frequency properties and practically based experimental methods which have been applied to determine them with an electrohydraulic vibration excitator. The possibility to usethese characteristics for linear mathematic models was described along with the manner to estimate dynamic characteristics based on the measurements of excitation and response of a physical object. The construction and control of a electrohydraulic vibration excitator is presented in brief and some basic information about the Remote Parameter Control method is also given. Measurement issues related to obtaining valuable signals have been presented with the focus on fundamental relations between the values of displacements and accelerations in various ranges of frequencies and some advice concerning the preparation of signal of test excitation were formulated. The process of measuring signal processing in order to estimate a power spectral density and then, based on thess results, the magnitude characteristics of a suspension is also presented. Differences in results obtained during computer simulation for linear model and for possibilities to use presented method in various areas of vehicle dynamics testing were highlighted.

PL

W artykule przedstawiono zastosowanie do oceny dynamiki zawieszenia charakterystyk amplitudowo-częstotliwościowych wraz ze zrealizowaną w praktyce metodyką wyznaczania w sposób eksperymentalny tych charakterystyk z wykorzystaniem stanowisk elektrohydraulicznych. Omówiono możliwość wyznaczenia tych charakterystyk dla liniowych modeli matematycznych, a następnie omówiono sposób estymacji charakterystyk dynamicznych na podstawie pomiarów wymuszenia i odpowiedzi dla obiektu fizycznego. Zaprezentowano krótko budowę i sposób sterowania elektrohydraulicznych wzbudników drgań oraz podano podstawowe informacje na temat metody Remote Parameter Control. Przedstawiono problemy pomiarowe związane z uzyskaniem wartościowych sygnałów, zwrócono uwagę na podstawowe zależności pomiędzy wartościami przemieszczeń i przyspieszeń w rożnych zakresach częstotliwości i wynikających z tego wskazówek w zakresie przygotowania sygnału testowego wymuszenia. Przedstawiono proces przetwarzania sygnałów pomiarowych w celu uzyskania przebiegów gęstości widmowych mocy mierzonych sygnałów, a następnie na ich podstawie oszacowania charakterystyk amplitudowo-częstotliwościowych dla testowego zawieszenia. Zwrócono uwagę na różnice w stosunku do wyników uzyskiwanych w symulacji komputerowej dla modelu liniowego oraz na możliwości wykorzystania przedstawionej metody w różnych obszarach badań dynamiki pojazdów.

3

The influence of damping changes on vertical dynamic loads of wheel – experimental investigations

Ślaski G., Pikosz H.

Archives of Transport

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2011

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Vol. 23, iss. 2

239-247

EN

In this paper the results of tests of vertical dynamic wheel loads due to changes in suspension damping level are presented. The changes in damping level were performed using semi-active shock absorbers with by-pass valve. The article presents suspension goals, the definition of dynamic loads of vehicle wheel, testing methods with the information on the used apparatus and sensors. In the end the results are presented, interpreted and compared with other researchers' results.

PL

W artykule przedstawiono wyniki badań pionowych dynamicznych obciążeń kół w zależności od zmian poziomu tłumienia zawieszenia dokonywanych z wykorzystaniem amortyzatorów o zmiennym w sposób ciągly tłumieniu, realizowanym za pomocą zaworów obejściowych. Artykuł przedstawia kolejno zadania zawieszenia, definicje obciążeń dynamicznych kół samochodu, metodykę badań i zastosowane stanowisko badawcze oraz czujniki. W końcowej części artykułu przedstawiono wyniki badań, zinterpretowano je i porównano z wynikami uzyskanymi przez innych badaczy.

4

Suspension dynamics and pavement wear

Pont de J., Steven B.

Engineering Transactions

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2000

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Vol. 48, iss. 3

221-242

EN

Recently a series of three accelerated dynamic loading tests was carried out at the Canterbury Accelerated Pavement Testing Indoor Facility (CAPTIF). The aim of these tests was to determine the influence of dynamic loading on pavement wear. This paper presents an investigation into the relationsips between the permanent vertical surface deformation (VSD) of the pavement, the applied dynamic wheel loads and the pavement structural stiffness. It is shown that the VSD was correlated with both the pavement stiffness and the dynamic wheel forces but that the relationship with wheel forces was highly dependent on the level of dynamic loading. A surrogate measure for pavement strainformed by combining pavement stiffness and wheel force into a single parameter provided the strongest correlation with VSD. Using this "strain" parameter as the independent variable of a power law predictor for VSD gives a best fit estimate for the exponent between one and two.