Cervical spine ligaments have an important role in providing spinal cord stability and restricting excessive movements. Therefore, it is of great importance to study the mechanical properties and model the response of these ligaments. In this study, we characterized and with the simplified approach modelled the ageing effects on the mechanical properties of three cervical spine ligaments: ALL, PLL and LF. A total of 46 samples of human cadaveric ligaments removed within 24–48 h after death have been tested. Uniaxial tension tests along the fiber direction were performed in physiological conditions on a custom designed test equipment. The results showed that ageing decreased the failure properties of all three ligaments (failure load, failure elongation). Mechanical response of cervical spine ligaments was modelled with simplified phenomenological model in 'toe' and linear region. The ageing effect on structural properties has been modelled with the simplified phenomenological model parameters represented as age functions in a manner useful for Finite Element Modelling of cervical spine ligaments. The ageing function had been added to the model in a manner to demonstrate a way of modelling of material properties of cervical spine ligaments of a donor between 20–80 years of age.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 13975579Whiplash injuries to the cervical spine represent a considerable economic burden on society with medical conditions, in some cases persisting for more than a year. Numerous studies of whiplash injuries have been made for occupant normal seated position, leaving the analysis of neck injuries for out-of-normal positions not well documented. For that purpose, a detailed human cervical spine finite element model was developed. The analysis was made for four most common occupant seated positions such as: Normal Position with the torso against the seat back and the head looking straight ahead, Torso Lean forward position with the torso away from the seat back for approximately 10°, Head Flexed position with the head flexed forward approximately 20° from the normal position and Head-Flexed with Torso Lean forward position with the head flexed forward approximately 20° and torso 10° from the normal position. The comparative study included the analysis of capsular ligament deformation and the level of S-curvature of the cervical spine. The developed numerical model predicted that the Head Flexed seated position and the Head-Flexed with Torso Lean forward seated position are most threatening for upper and lower cervical spine capsular ligament respectively. As for the level of S-curvature, the numerical model predicted that the Head-Flexed with Torso Lean forward seated position would be most prone to neck injuries associated with it. This study demonstrated that the occupant seated position has a significant influence on potential whiplash injuries. With the use of developed numerical model further investigation of the whiplash injury mechanism is possible enabling better occupant's protection. The results significantly improve understanding of the whiplash injury, since the ideal body posture was assumed in many of the existing studies. The conclusive results were made possible only after validation of the neck model developed and obtaining adequate data on mechanical properties of the neck anatomical structures.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 14908187This paper presents the use of computer simulations as the approach of determining the possible causes of various injuries sustained by motorcyclists in traffic accidents. In this research several typical motorcycle accidents were simulated. For simulating the motorcycle accidents, the FEM models of the Kawasaki ER-5 motorcycel, Suzuki Swift car and Hybrid III dummy were used. Based on the literature review, several most common motorcycle accidents scenarios were determined and simulated with the use of the LS-Dyna FEM software. Simulations results were then analysed to determine the loads and possible injuries on the individual body segments of motorcyclists. Simulation results were also used to determine damage to the accident involved vehicles and to correlate it to the impact speed, which is often difficult to determine. The paper findings can be helpful for forensic experts in determining the cause of various impact injuries in motorcyclist victims as well as for im-proving the road safety.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 13275675An increase in the number of traffic accidents in tunnel emergency stop areas has been recored in the last two years in many countries with long road tunnels. In most cases, the collisions of passenger cars into the emergency stop area walls were fatal, which presents an even bigger obligation for the road management authorities to find a solution to the problem. Even though the tunnel emergency stop areas are designed and built according to the valid legislation, it has turned out that the current implementation of the emergency stop area wall in the driving direction presents a serious potential traffic safety risk. With the purpose of determining the most suitable method of protecting the SOS tunnel niche wall in the event of vehicle impacts, comparative numerical analysis of vehicle impacts has been performed in accordance with the SIS - EN 1317 standard. For the emergency-stop-area wall-impact protection, two different designs were considered: the H2 safety railing and the crash cushion composed of eight cylindrical steel sheet tubes. Based on the FEM analysis results in LS-Dyna for each crash scenario, a comparative analysis of the two protection systems was performed in order to determine their efficiency and suitability for installation in the existing tunnel emergency stop areas. Based on comparative analyses of the values of the Acceleration Severity Index (ASI), Theoretical Head Impact Velocity (THIV) and values of the Post-Impact Head Deceleration (PHD), the crash cushion provides the best results for collisions of vehicles into an SOS tunnel niche.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 15098907In the field of traffic informatics a database has been developed and implemented, currently containing the data about traffic accidents in Slovenia (from 1994 to 2015), the infrastructure data (from different sources: Ministry of Infrastructure, Surveying Agency, OpenStreetMap), base layers with different maps and orthophotographs, and other local data (e. g. the AADT data for the area of the City of Ljubljana). For the display of data on an interactive map a web application has been developed. It provides the end users with the options of customising the map view based on various criteria. The development also included algorithms for classification of conflict points (crossing points, crossings, roundabouts, railway crossings), which are used for preliminary testing of conflict point ranking according to different safety criteria. On the collected traffic accident dataset, a quality analysis has been performed using the machine error correction algorithms developed for this purpose.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 14624027