Road Safety Barriers and the Safety of Road Users – the Analysis of the Situation in Poland

Road safety barriers are a basic element of the road infrastructure aimed at improving the safety of road users. Design parameters and indications for assembly are strictly regulated by the GDDKiA (General Directorate for National Roads and Motorways) guidelines in accordance with the European standards. In Poland, the most commonly used barriers are thin-walled metal sheet barriers, rope barriers, and concrete ones. The types differ in terms of technical parameters and level of security they provide. One of the purposes of installing road safety barriers is to protect road users from hitting an obstacle in the vicinity of the road, and to protect people around the accident from the effects of an uncontrolled vehicle leaving the road. The effects of a collision caused by hitting a protective road barrier depend mainly on the type of the barrier and the vehicle. The authors made a detailed and interdisciplinary analysis of data on accidents resulting from hitting a road safety barrier, comparing them with information available in the literature, combining the technical aspects of the use of barriers with a medical description of the description of typical injuries

The investigations of suspension model and its experimental characteristics for the air springs of truck trailer

Air springs applied as shock damping elements are often found in the design of variety modern truck and trailer suspensions. They can also be found as damping and stabilizing suspension elements in the passenger cars and other machines. The advantage of air springs, compared to steel coil springs or leaf springs, is a better damping quality in a wide range of frequencies. The air springs stiffness can be regulated according to the requirements and working conditions. The applied air springs also allow to stabilize the distance between the vehicle body and road level in function of loading. Some proposals of vehicle suspension models can be found in technical literature where the air spring is the main elastic subassembly. Mathematical model descriptions of the suspension with air spring for vehicles apply the thermodynamic laws and relationships between the mechanical forces of cooperating suspension elements, parts geometry (suspension arms), material stiffness (reinforced rubber) and other properties (damping). The results of own investigations on the suspension model of an air spring for cargo trailer have been taken into consideration in this paper. The presented suspension model was applied to design the frame construction of a light stanchion trailer where aerodynamic drag and construction mass were reduced. The suspension model of air springs for a trailer was applied for frame loads evaluation of the light trailer. It was also used for the strength analysis of the frame construction with the reduced mass. The estimated frame loads such as torque, normal forces and bending moments were used for strength estimation of the upgraded trailer frame

Road Safety Barriers and the Safety of Road users – the Analysis of the Situation in Poland

Road safety barriers are a basic element of the road infrastructure aimed at improving the safety of road users. Design parameters and indications for assembly are strictly regulated by the GDDKiA (General Directorate for National Roads and Motorways) guidelines in accordance with the European standards. In Poland, the most commonly used barriers are thin-walled metal sheet barriers, rope barriers, and concrete ones. The types differ in terms of technical parameters and level of security they provide. One of the purposes of installing road safety barriers is to protect road users from hitting an obstacle in the vicinity of the road, and to protect people around the accident from the effects of an uncontrolled vehicle leaving the road. The effects of a collision caused by hitting a protective road barrier depend mainly on the type of the barrier and the vehicle. The authors made a detailed and interdisciplinary analysis of data on accidents resulting from hitting a road safety barrier, comparing them with information available in the literature, combining the technical aspects of the use of barriers with a medical description of the description of typical injuries

Experimental and analytical approaches to the mechanical resistance of moped tire under impact

The aspects related to the dynamic modeling of the mechanical properties of motorcycle tires following the practical application of research methods have been analyzed for many years. A test stand was constructed for the examination, and a mathematical model was proposed to calculate tire parameters. This study aims to develop the characteristics of the radial dynamic stiffness of a pneumatic tire depending on the pressure in the tire, speed of the beater simulating tire slipping onto a small obstacle lying on the road, and impact damping. The testing device was designed to simulate a sudden strike of a tire on a stiff foreign body lying on a road plane. The experiment was performed for three different values of air pressure in the tire, beater rate, and impact energy of the tested wheel. The dynamic radial stiffness of pneumatic tires decreased with increasing deformation speed and pressure. Presented in the paper research methodology can be an introduction to further, more complicated research, where will be taken into consideration factors such as wheel rotation, driving or breaking the wheel, friction, etc. The proposed methodology can be extended to assess the dynamic adhesion coefficient during tire impact loading

Analytical approach for vehicle body structures behaviour under crash at aspects of overloading and crumple zone length

Road safety problem is still topical, especially since the number of vehicles and the volume of traffic are increasing. It is possible to increase the safety of road users through systemic changes in many areas related to transport. The deformation of the vehicle body during an accident has an impact on the loads acting on the passengers. Vehicle body deformation depends on complex parameters, and knowledge of these parameters is essential for designing crumple zones and the accident reconstruction process. Knowledge of the mechanical parameters of the vehicle structure during deformation is also a reference to passenger injury indicators assessment. This paper reports results from the analytical approach for determining the protection level of personal vehicles. The proposed conception is based on the results from the static stiffness characteristic of the Ford Taurus, which gives the possibility of phenomenological and simple body crumple analytical description at a speed equal to 10 km/h, 40 km/h, 56 km/h and 60 km/h, which is an original part of the work. The approach enables us to describe the vehicle crash by focusing on variations of deformation in time, stiffness, vehicle collision time (duration), deceleration and dynamic crash force. Basing on the body stiffness data of the personal vehicle, the length of the deformation zone in the front of the car and the maximum values of force at the crash for a speed of 60 km/h are presented. Results obtained by the authors show that is possible to estimate the overloading level during the crash time of a vehicle based on the stiffness characteristic of the car body. The proposed methodology can be developed and the advantage of the presented procedure is an uncomplicated useful tool for solving complex problems of a vehicle crash

Motorbike protective helmets, construction, testing and its influence on the type and severity of injuries of motorbike accident casualties: a literature review

A motorcycle or moped helmet is currently mandatory, and provides basic protection to the user of a motor-powered two-wheeler against the possible consequences of a road accident. A wide market offer of various protective helmets allows one to choose from many different design solutions used by the manufacturers. The introduction of a protective motorcycle helmet is associated with the need of meeting the conditions set out in legal regulations. In recent years there have been changes in the legal provisions regarding to protective helmets and the conditions imposed on helmets are becoming more and more restrictive. There have also been changes in the conditions for conducting the helmet approval tests. Regulations valid in Europe include the Economic Commission of Europe (ECE), whereas regulations in the United States are created by the Department of Transportation (DOT). Despite the advanced construction of protective helmets, various test methods, and changes in legal regulations, the problem of the effective protection of the heads of two-wheeler users remains valid. The article presents an actual state of constructions for motorbike helmets, safety level, testing methodology and actually applicable law regulations. This analysis includes a wide medical description of motorcyclist injuries and helmet obstacle impact behaviour. Further studies are required to estimate the head and neck injuries caused by accidents involving motorcycles and other materials. Therefore, construction and testing methods should be developed accordingly. This review presents the current state of knowledge that can be used as the basis for helmet tests and medical assessments of body injuries

Dynamic Model of a Humanoid Exoskeleton of a Lower Limb with Hydraulic Actuators

Exoskeletons are the mechanical systems whose operation is carried out in close cooperation with the human body. In this paper, the authors describe a mathematical model of the hydraulic exoskeleton of a lower limb. The coordinates of characteristic points of the exoskeleton in the sagittal plane as a function of user height are presented. The mathematical models, kinematics, and kinetics equations were determined. The masses of the actuators and their dimensions were selected based on catalog data. The force distribution in the wearable system during the squat is shown. The proposed models allowed us to determine the trajectory of individual points of the exoskeleton and to determine the forces in hydraulic cylinders that are necessary to perform a specific displacement. The simulation results show that the joint moments depend linearly on actuator forces. The dynamics equations of the wearable system are non-linear. The inertia of the system depends on the junction variables and it proves that there are dynamic couplings between the individual axes of the exoskeleton

Cases of fatal electrocution due to contact between carbon fibre fishing rods and overhead power lines

Abstract Background Electrocution caused by electricity conducted via overhead power lines carries a high risk to health and life. With the introduction and proliferation of conductive carbon fibre fishing tackle, severe and fatal electrocution occurs due to accidental contact with overhead transmission lines. Case presentation The paper presents three cases of men who died due to electrocution from a conductive fishing rod, which occurred in the same fishery over several years. The deaths occurred on the spot in two cases despite rapid rescue efforts. One of the men died in the hospital the following day due to developing severe complications. Additionally, all of the victims were under the influence of alcohol at the time of the incident. During postmortem diagnosis, skin lesions were identified as signs of electric shock on the hands and feet in each case. To the best of the authors’ knowledge, there is no similar case series available in the literature where several almost identical fatal electrocutions occurred in the same place as a result of contact of a fishing rod with overhead power lines. Conclusions Action is needed to avoid similar incidents and to increase safety in the vicinity of power lines

Relationship Between Anti-DFS70 Autoantibodies and Oxidative Stress

Background: The anti-DFS70 autoantibodies are one of the most commonly and widely described agent of unknown clinical significance, frequently detected in healthy individuals. It is not known whether the DFS70 autoantibodies are protective or pathogenic. One of the factors suspected of inducing the formation of anti-DFS70 antibodies is increased oxidative stress. We evaluated the coexistence of anti-DFS70 antibodies with selected markers of oxidative stress and investigated whether these antibodies could be considered as indirect markers of oxidative stress. Methods: The intensity of oxidative stress was measured in all samples via indices of free-radical damage to lipids and proteins such as total oxidant status (TOS), concentrations of lipid hydroperoxides (LPH), lipofuscin (LPS), and malondialdehyde (MDA). The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid concentration (UA), were also measured, as well as the activity of superoxide dismutase (SOD). Based on TOS and TAS values, the oxidative stress index (OSI) was calculated. All samples were also tested with indirect immunofluorescence assay (IFA) and 357 samples were selected for direct monospecific anti DFS70 enzyme-linked immunosorbent assay (ELISA) testing. Results:: The anti-DFS70 antibodies were confirmed by ELISA test in 21.29% of samples. Compared with anti-DFS70 negative samples we observed 23% lower concentration of LPH (P = .038) and 11% lower concentration of UA (P = .005). TOS was 20% lower (P = .014). The activity of SOD was up to 5% higher (P = .037). The Pearson correlation showed weak negative correlation for LPH, UA, and TOS and a weak positive correlation for SOD activity. Conclusion: In samples positive for the anti-DFS70 antibody a decreased level of oxidative stress was observed, especially in the case of samples with a high antibody titer. Anti-DFS70 antibodies can be considered as an indirect marker of reduced oxidative stress or a marker indicating the recent intensification of antioxidant processes