Multibody study of the dynamic behaviour of a tracked vehicle under different operating conditions

This thesis focuses on analyzing and modeling the behavior of tracked vehicles in various operating conditions using the Adams Car software, with particular emphasis on the Adams Tracked Vehicle (ATV) toolkit. The primary aim is to simulate the realistic dynamics of a tank by modifying key parameters such as vehicle speed, track tensioner force, and terrain conditions. Thanks to them it is possible to obtain important results according to the pressure-sinkage diagram, the contact area, the longitudinal slip, the vertical stiffness, the maximum track deflection and the track motion resistance coefficient. Additionally, the study examines the vehicle's response on both hard (dry and wet asphalt) and soft (dry sand and soft snow) soils, as well as flat and inclined terrains with slopes up to 40%. The simulations mainly explore the longitudinal dynamics, but also with two chapters dedicated to static (study of the idler, support and sprocket vertical forces), and lateral dynamics (steering maneuver). The central goal is to replicate existing maneuvering tests, such as those conducted at CEPOLISPE (Centro Polifunzionale di Sperimentazione dell'Esercito), where experimental trials are carried out. A key requirement of this research is the ability to predict the tank's performance before physical testing. This approach scrupulously investigates lots of physical variables critical in order to define the dynamics of tracked vehicles, ensuring compliance with military operational need well in advance of actual deployment. Modeling allows the Italian Army to challenge potential vehicle performance in scenarios that have yet to be tested. The instruments used in this thesis work include Adams Car, its ATV toolkit and specifically its default tank model for reasons of extremely long simulation computation times. Matlab was exploited during the post-processing of data using a specific conversion script. Furthermore, ground analyses were conducted on the real ARIETE tank at CEPOLISPE, where different sensors were installed to experimentally validate the digital model. Equipment used includes a wire potentiometer, accelerometer, IMU (Inertial Measurement Unit), RTK antenna (Real-Time Kinematic), and Simcenter Scadas XS, essential for dynamic track vibration measurements. Unfortunately, within this paper, due to confidentiality reasons, only the results related to vibrations, got using the last mentioned sensor, have been shown. Ultimately, this large-scale project has the great purpose to develop a systematical approach able to deal with numerous simulations without the need for continuous physical testing, thereby achieving significant resources, time, costs and efforts savings. Moreover, this simulation-based work reduces possible component wear and enables remote analysis, solving the problem of extensive logistical organization to carry out all the tests on the real tracked vehicle.