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Nowadays, attempts to commercially apply non-pneumatic tires (NPTs) in a wide range of vehicles can be observed. These types of wheels use a specific structure and material selection to mimic the function of compressed air in pneumatic tires (PTs). This paper reviews the mechanical properties and vehicle applications of non-pneumatic tires. This review will provide information about the influence of the shape of the radial, longitudinal, and lateral characteristics, as well as the possibility of selecting contact pressure values at the wheel design stage and the influence of the type of elastic structure on the concentration of pressures in the contact length. The radial characteristics of non-pneumatic tires depend on the type of elastic structure. The spoked elastic structure will be characterized by greater displacements compared to the cellular structure, which will reduce radial stiffness. The radial stiffness of non-pneumatic tires is increased by increasing the number of elastic structure elements and their thickness and decreasing their length. The longitudinal stiffness of non-pneumatic tires increases with the number of elements forming the elastic structure and with the elastic structure’s lack of susceptibility to circumferential deformation. Spoked non-pneumatic tires will have lower longitudinal stiffness compared to cellular non-pneumatic tires. The elastic structure is characterized by a low susceptibility to lateral deformation, which contributes to the high lateral stiffness of the non-pneumatic tire. Non-pneumatic tires have a limited ability to shape the contact patch parameters, which mainly depend on the vertical load and the shape of the tread area. The type of band used will influence the formation of contact pressures. An isotropic elastomer used in a shear band will cause pressure concentration at the ends of the contact length. A more uniform pressure distribution is achieved by using a laminated elastomer.

This paper presents the results of a study on the effects of low car speeds and the elastic-damping properties of tires on steering effort. “Steering effort” is a measure of the demand/energy consumption of the power steering system that limits the force applied by the driver to the steering wheel. Low driving speeds, on the other hand, are characteristic of urban traffic, where we would like to see as many electric cars moving as possible. An increase in “driver effort” means a higher electricity consumption and shorter car range. In this study, energy intensity was evaluated for a typical maneuver such as a double lane change. For this purpose, measurements were made of the torque on the steering wheel, the speed of the car, and the lateral accelerations acting on the car. A torque wheel, an optoelectronic sensor for measuring the components of the car’s motion, and an acceleration sensor were used for the study. The test subjects were two passenger cars with hydraulic power steering systems. The tests were carried out for four values of air pressure in the tires. This made it possible to determine four work charts for each wheel. The work charts made it possible to identify the stiffness and damping coefficients of the tires for the tested cars. The values of the coefficients were used to determine the correlation between the directional coefficient of the regression lines of the skeletal axes of the elastic and damping characteristics and the index determining steering effort.

This article deals with the influence of the elastic-damping properties (energy losses) of tired wheels on the results of the evaluation of the technical condition (dynamic properties) of automotive suspensions carried out on the diagnostic line. The purpose of this paper is to point out the inadequacies of test stands for assessing the technical condition of vehicle suspensions. The diagnostic line used in the testing featured two testing stations. The test object was a passenger car with hydro-pneumatic suspension. This enabled the conducting of suspension tests for two settings (comfort and dynamic positions). The tests were conducted for four different air pressures in the tyres of tired wheels. This made it possible to determine, for each wheel, four graphs of the load versus tyre deflection (radial stiffness characteristics). These graphs were used to determine the values of the stiffness coefficients, energy loss, and damping characteristics as well as to identify the correlation between the directional coefficient of the regression line of the elastic and damping characteristics of the tyres and the indices characterising the damping properties of the suspension of the test car. This paper shows that the result of the shock absorber condition assessment is significantly influenced by the elastic and damping properties of the tired wheels, caused by changes in tyre pressure.

The article presents the results of research on the steering effort involved in performing two different maneuvers. One of them was a turning maneuver and the other was a double lane change maneuver. These are typical road maneuvers that result from various traffic situations. During the experiment, the torque acting on the steering wheel, the vehicle speed, and the lateral acceleration values generated during movement were recorded. The object of the study was a light bus equipped with a hydraulic power steering system. Road tests were conducted for three vehicle speeds and four different tire pressures, and the shock absorption properties of the wheels were determined based on performance charts. The tests carried out (cornering maneuver and double lane change) and the values recorded during their implementation, such as vehicle speed, lateral acceleration, steering angle, and steering torque, made it possible to determine the relationship between steering effort and the energy (elasticdamping) properties of the wheels of the tested car.

The Rear Underrun Protective Device (RUPD) is a basic means to prevent a passenger car from running under the rear of a motor truck (also referred to as heavy goods vehicle or HGV) or a trailer in the case of a rear-end collision and thus to reduce deformations of the car’s passenger compartment (“survival space”). In many publications dealing with such devices, the increasing of RUPD stiffness by applying innovative design solutions or using high-strength materials has been considered; in some designs, additional RUPD components are introduced to absorb the impact energy. In this paper, a review of the RUPD designs is presented and some of them are analyzed, where their characteristics that are essential for the compliance with normative market requirements are indicated. Results of the authors’ research on the selection of an energy absorber incorporated in the rear impact guard bar of an HGV are presented as well.

The rapid transition to electric-drive vehicles is taking place globally. Most automakers are adding electric models to their lineups to prepare for the new electric future. From the analysis of the automotive market, it is evident that there is a growing interest in such vehicles. They are expected to account for half the models released after 2030. Electric-drive vehicles include battery-electric vehicles. As indicated in the research literature and emphasized by experts, electric vehicles (EVs) are supposed to be an environmentally friendly alternative to conventional vehicles. The rising number and variety of EVs contribute to a better understanding of their performance. With more EVs on the market, there are problems to be solved and challenges to overcome. This article is the first part of a two-article series reviewing the strengths and weaknesses of EVs. The article analyzes the environmental effects of EVs at each stage of their life cycle, compares large- and small-scale recycling methods, and explores the potential applications of second-life batteries. This article is an attempt to find out how environmentally friendly EVs are.

This paper deals with the issues of the impact of vertical vibrations on a child seated in a child seat during a journey. Its purpose was to assess the impact of fastening the child seats and road conditions on the level of vibrations recorded on child seats. The paper describes the tested child seats, the methodology of the tests and the test apparatus included in the measuring track. The tests were carried out in real road conditions where the child seats were located on the rear seat of a passenger vehicle. One was attached with standard seat belts, and the other with the ISOFIX base. When driving on roads with three types of surface, the following vertical accelerations were measured: seat of the child seats, the rear seat of the vehicle and the ISOfix base. The recorded accelerations were first analyzed in the time domain and then in the frequency domain. Three indexes (r.m.s, rmq and VDV) were used to assess the vibration comfort. Research has shown that the classic method of fastening a child seat with standard seat belts is more advantageous in terms of vibration comfort. Calculated indicators confirmed the negative impact of separating the child seat from the rear seat of the vehicle using the IQ ISOFIX base.

The non-pneumatic tire (NPT) is a type of wheel whichdevelopment is related to the beginning of automotive development. The non-pneumatic tire (NPT) is a type of tire that does not contain compressed gases or fluid to provide directional control and traction. Nowadays, this type of wheel is more and more often used in special purpose vehicles, e.g., in military vehicles and working machines. The main feature of the non-pneumatic tire is a flexible support structure (including the part of the wheel between the tread and the rim). This paper presents the results of research aimed at determining the influence of the geometry of the NPT’s (intended for All-Terrain Vehicle–ATV/Utility Task Vehicle–UTV) load-bearing structure on its quasi-static directional characteristics. The experimental tests included the determination of the radial stiffness of research objects on a non-deformable flat surface and on a single obstacle, as well as the determination of the degree of deformation for the elastic structure and belt. The significant influence of the elastic structure’s shape and the elastomer, as the material forming the NPT, on its radial stiffness was revealed.

Selected structures intended to absorb impact energy have been analysed in respect of their use in the rear underrun protective devices (RUPD) of motor trucks. The main purpose of the RUPD is to prevent a passenger car from running under the rear of a motor truck provided with such a device. From the point of view of the safety of the car occupants, it is important to take into account the components whose additional role would be to absorb a part of the impact energy so that the loads on the said occupants were minimised. This article presents experimental test results concerning selected energy-absorbing structures. Based on quasi-static strength tests, simplified material models were defined. As a result of experimental crash tests, the possible applications of selected energy absorbers to the RUPDs as their components accountable for the passive safety of passenger cars were indicated. Absorbers proposed in this paper can be considered effective energy-absorbing structures, e.g., in the case of the central impact of a medium-class car with a speed of about 40 km/h. They are relatively inexpensive in production and easily implementable to motor trucks, even taking into account some limitations related to the type-approval regulations on the European market.

The electrification of road transport is developing dynamically around the world. Many automotive companies are introducing electric vehicles to the market, and their popularity is constantly growing. The increasing popularity of electric vehicles is caused by individual countries’ governments encouraging people to switch to electric vehicles and their lower operating costs. In 2022, the number of electric vehicles in China will exceed 10 million. Europe and the USA rank second and third in global electric car stock, respectively. The number of available electric vehicle models is constantly growing, remaining approximately 2.5 times smaller than the case of vehicles with an internal combustion engine. Among others, a significant limitation to the popularity of electric cars is users’ fear of range and the density of the charging infrastructure network. This paper presents the objectives regarding public areas and charging stations around the European Union’s comprehensive and core transport network. It is worth noting that the vehicle and charging point’s charging connectors vary depending on the geographical region. Therefore, the currently used charging connectors for different regions are presented. Charging time depends significantly on the charging current, the power of the charging point, and the devices installed in the vehicle. The paper analyzes the limitations of charging power resulting from the onboard charger’s power and the charging point’s power. It presents the charging time of selected electric vehicles. The second aspect that is also the subject of user concerns and discussed in this article is issues related to the safety of electric vehicles. General safety indicators of such vehicles based on Euro-NCAP tests are characterized. Attention was also paid to more detailed problems related to active and passive safety and functional safety analyses. The issue of the fire hazard of electric vehicles was discussed together with modern experiences regarding post-accident procedures in the event of fires.