Wyniki wyszukiwania - Biblioteka Nauki

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Comparison of various types of damage symptoms in the task of diagnostic composite profiles

100%

Markuszewski D.

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tom Vol. 20, No. 3

105--110

EN

The current trend of weight reduction entails a reduction in safety factors. This approach is understandable, but light profiles are more susceptible. The structure works close to the boundary loads, and their destruction is primarily determined by dynamic relief. Today, composite masts are diagnosed by the following methods: optical microscopy, electron microscopy, X-ray analysis and thermal analysis. These methods are invasive methods. It seems that the vibration analysis of the mast - rigging system could supplement or replace the mentioned methods without the need to dismantle the mast, giving the possibility of testing on the yacht [5]. The article presents the possibility of diagnosing a composite material defect on the example of a interrupts a continuity of structure.

PL

Obecna tendencja do redukcji masy pociąga za sobą obniżenie współczynników bezpieczeństwa. Takie podejście jest zrozumiałe, ale lekkie profile są bardziej podatne. Konstrukcja pracuje blisko obciążeń granicznych, a o ich zniszczeniu decydują przede wszystkim odciążenia dynamiczne. Współcześnie maszty kompozytowe diagnozuje się następującymi metodami: mikroskopii optycznej, mikroskopii elektronowej, analizy rentgenowskiej i analizy termicznej. Wymienione metody są metodami inwazyjnymi. Wydaje się, że analiza drgań układu maszt - olinowanie mogłaby uzupełnić lub zastąpić wymienione metody bez potrzeby demontażu masztu, dając możliwość wykonania testu na jachcie [5]. W artykule przedstawiono możliwość diagnozowania defektu materiału kompozytowego, polegającego na przerwaniu ciągłości struktury osnowy.

2

Laboratory Tests of Rolling Resistance of Different Tread Profiles for the Wheel of Martian Roverr

63%

Gorzym M. , Markuszewski D.

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tom Vol. 18, no 3

280--295

EN

The aim of the research was to design and build a research stand that can be used to compare different types of tire tread profiles of the Mars rover (made using 3D printing) and to select the one that meets the criterion of the lowest power consumption of the drive motor, which corresponds to the minimum rolling resistance in paved area. As part of the task, a research stand was designed and built, consisting of two drive units of the tested drive system: one as a driving unit, the other as a driven unit, generating resistance when rolling one tire after another. During the tests, the following parameters were measured: the amplitude of the supply current, the rotational speed, information about which was obtained from the motor controller and the encoder located in the BLDC motor, and their variability over time. Additionally, the amplitude of the force pressing the wheel against the supporting surface, which generated tire deflection, was also measured. A relationship was demonstrated between the type of tire tread used, the force pressing the tires against the supporting surface and the rolling resistance forces of the Mars rover tires. The tire with the lowest rolling resistance under given operating conditions was selected.

3

Concept of a Composite Frame of a Martian Vehicle

51%

Markuszewski D. , Wądołowski M. , Gorzym M. , Bielak M.

Advances in Science and Technology. Research Journal

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2021

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tom Vol. 15, no 4

222--230

EN

The presented article describes the design and strength analysis of the frame of the Mars rover, which will start in the European Rover Challenge. The shape of the frame is determined by the six-wheeled rocker-bogie suspension chosen for the project, which is characterized by high stability and even distribution of wheel pressure on the ground and a reduction in the vibration frequency of the frame in which the vehicle electronics are located. The adopted slants counteract the swinging frame on the suspension, which has been checked by kinematic analysis. The design uses the concept of a frame structure made of sandwich walls, consisting of: 3D printed elements - an openwork grille with a honeycomb structure, a low-pressure foam filler and a carbon composite made of a combination of three layers of carbon fiber mat with a 1z1 weave and 0/45 /90 orientation with Epidian 5 epoxy resin ensuring equal spacing between the layers. Such a combination of materials allowed for a very durable and light structure with a significant reduction in weight compared to the original concept - an aluminum frame. A "cross"-shaped support element was also used, connecting the upper part of the frame with the lower one - also made in the 3D printing technique, which is also a link between the frame and suspension. The analysis showed that the materials and sections of structural elements adopted for the project are appropriate for the assumed load. In the case of unloading from the manipulator, the authors proposed to increase the safety factor due to the possibility of an additional load from dynamic forces. In places where reduced stresses reach increased values, additional reinforcements are provided.