PSI - Issue 73

Veronika Valašková et al. / Procedia Structural Integrity 73 (2025) 155–162 Author name / Structural Integrity Procedia 00 (2025) 000–000

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structure development, micro-tremor, etc ., Čorej (2006) . The task can be solved by experimental or by the numerical way , Bittnar and Řeřicha (1981), Čačko et al. (1984), Němec et al. (2010) . But the most effective way is the combination of the both mentioned advances. The submitted article is dedicated to the description of facilities how to obtain the required data by the numerical way in the time domain using FEM (Finite Element Method) program system ADINA. The single layer and multilayer models based on shell and solid elements are introduced. The results of the calculation are stress and strain states in the entire road construction. 2. Methodology In following sections, a description of the FEM model inputs is introduced in relation to the boundary conditions of the numerical models. 2.1. Vehicle model Generally, various calculation models of the vehicle can be used in the numerical simulations of structural dynamic tasks. Simple models of vehicles, such as moving loads or moving masses were elaborated in past studies, Baťa et al. (1987) . Recently, models based on the multi-body principle are implemented in the modern approaches. The principle is based on a system of masses connected together by rigid or flexible links. Multi-body system method is frequently utilized for description of the movement of solid bodies, connected to each other by rigid, flexible or load links. The mathematical description of the solid body motion is formed by equations of the motion. The solution gives the results in means of quantities such as displacement, velocity and acceleration of discrete points of the solved system. The selection of the computational model of vehicle depends on the calculation requirements or computation time restrictions. In the case of more complicated simulations, where the planar model is not sufficient, a more complex, spatial model of the vehicle is required, Valašková et al. (2015), Valašková and Vlček (2017) . This approach leads to a more extensive modelling process than in case of a planar model. For this case, a full vehicle spatial model was constructed. The geometry of analyzed 6-axle vehicle is displayed in Fig. 1a. The model created on the FEM principle is shown in Fig. 1b. For the modelling, the 3D SOLID elements were adopted. Their material properties do not interfere with the calculation and only have a visual function.

Fig. 1. (a) geometry of the modeled vehicle (dimensions in mm); (b) spatial model of vehicle, 1 – linear spring with damping, 2 – beam element, 3 – 3D solid element, 4 – mass point.

The vehicle model is transversely symmetrical. For this reason, some transverse characteristics of the model occur two times. The parameters of the individual model elements such as the mass, stiffness and damping characteristics are shown in Table 1.