DOI: 10.33963/KP.15653, Published online: October 21, 2020, Authors: Magdalena A. Bryndza, Radosław Litwinowicz, Stanisław Bartuś, Marcin Nosal, Jacek Godlewski, Anna Orzechowska, Andrzej Wiśniewski, Renata Korpak-Wysocka, Łukasz Rzeszutko, Paweł Kocik, Jerzy Matysek, Artur Klecha, Łukasz Wiśniowski, Jarosław Blicharz, Maciej Maliszewski, Grzegorz Filip, Bogusław Kapelak, Krzysztof Bartuś, Jacek Legutko

Modern wheeled armoured vehicles can perform a variety of tasks, making the development of weapon systems that can be safely and effectively integrated with the vehicle structure an area of interest. Due to the cost of implementing new models, it is more economical to test potential configurations using numerical methods, such as the finite element method. The numerical model has been validated to confirm the reliability of the obtained results. Modal tests were also performed using four configurations to identify the frequency and mode shape of natural vibrations occurring within the support structure. In an experimental setting, hull vibrations were forced using the modal hammer testing method. The modal assurance criterion (MAC) and the authors’ procedure were used to confirm the experimental and numerical test results. Additional testing in the form of impact loads was carried out for turret-containing structures. Structural strain at indicated points and forces transmitted by brackets to the bottom of the hull were compared.

The operation of high-speed tracked vehicles takes place in difficult terrain conditions. Hence, to obtain a high operational reliability, the design or modernisation process must be precise and should consider even the slightest details. The article presents issues related to the problem of formulating vehicle models using partial models of flexible elements used in tracked mechanisms. Changes occurring in the shape and properties of elements such as track pads and roadwheel bandages as a consequence of operating conditions are presented. These changes are reflected in the presented elastic–damping characteristics of components of the crawler mechanism. Numerical studies have shown that deterioration of chassis suspension components after a significant mileage may increase dynamic loads (forces) acting on the running gear. Increased forces in the running gear naturally result in increased stresses in the road surface on which the vehicle is travelling, which can pose a danger (or excessive wear and tear) to road infrastructure components such as culverts, bridges and viaducts. In the literature, model tests of objects are carried out on models that represent new vehicles, and the characteristics of the adopted elements correspond to elements not affected by the process and operating conditions. Its influence should not be ignored in the design, testing and running of a special vehicle. The tracked mechanism, as running gear, is designed for special high-speed vehicles for off-road and off-road driving. Its design ensures high off-road traversability. The dynamic loads originating from off-road driving are superimposed on those generated by the engine, drive train and interaction of the tracks with the roadwheels, sprocket, idler and supporting tracks return rollers.

This paper presents the results of experimental investigations of the effects of car wheel unbalance on driving safety and comfort. Basic information about types of wheel unbalance, their causes, and effects are included. The test subject was a BMW 3 Series car with rear-wheel drive. A specific unbalance was introduced on the front steered wheels. The vehicle was driven in a straight line on an asphalt road in good condition at speeds between 70 km/h and 140 km/h. During the test runs, acceleration waveforms were recorded from sensors placed on the lower control arm, driver's seat, and steering wheel. The vibration level of the unbalanced wheel increases with the driving speed and with the increase in unbalance. The highest increase in vibration amplitude occurred on the steering wheel at speeds between 100 km/h and 120 km/h. These vibrations have a direct effect on the driver. This is evidenced by negative driver perceptions such as fatigue and driving discomfort. This was also confirmed by the calculated vibration exposure levels. Driving with unbalanced wheels accelerates wear on the tyres, steering, drive, and suspension components of the vehicle.

This paper present development trends for modern wheeled armored vehicles construction including armament. The possibility of safe use of weapon system with 120 mm cannon was considered. For this purpose, finite element model of vehicle roof plate was refined. Recoil force (impulse magnitude and duration) of large caliber cannon to determine dynamic loads acting on the hull of vehicle was defined. Preliminary results of dynamic loads from large caliber cannon (120 mm) acting on wheeled armored transporter hull construction, influence on vehicle stability and dynamic deflection values was determined Numerical researches were taken for initially gravity loaded standing still on flat ground vehicle conducting firing tasks in in total for four scenarios: firing forward and left (azimuth 0 and 90 deg.) and for different cannon elevation angles (0 and 16 deg.) for each azimuth.