Rollover Accidents Research Articles

Numerical child restraint system analysis in 6 years old infant during a dolly rollover test

This research analyzes the head and chest injuries with a finite element model of Hybrid III six years old during the vehicle rollover, using a passive safety Child restraint system (CRS). Vehicle seats and passive safety systems were modeled in CAD software. Subsequently, all elements were analyzed using the finite element method in the LS-DYNA® software. The border conditions were established for each study, in accordance with the Federal Motor Vehicle Safety Standard (FMVSS), following the FMVSS 213 standard for the mounting and fastening of the infant, the FMVSS 208 for the dolly rollover test methodology with which the vehicle rollover was performed. The vehicle Toyota Yaris 2010 was considered in all the analyzes. The numerical simulations were performed during an interval of 1 s, and there were obtained values every 2 ms to analyze the efficiency of the system and the restriction performance of the CRS system. It was compared the behavior when the chair uses a 5-point seatbelt, with respect to using the 3-point seatbelt, and what happens when holding the chair with the single seatbelt and with the ISOFIX anchorage. Three cases of studies were analyzed: Study I; CRS Study II; CRS with ISOFIX anchorage; and Study III; CRS with a seatbelt of 5-points. The outcome shows that the best restriction efficiency is that of the CRS 5 points seatbelt because it presents the lowest level of chest injury. In conclusion, the main factor to reduce injuries during a rollover accident is the correct anchoring of CRS, this is achieved with ISOFIX system, on the other hand, a good quality of material and a correct thickness used for the headrest could reduce the risk of a head injury.

Numerical Low-Back Booster Analysis in a 6-Year-Old Infant during a Dolly Rollover Test

This paper analyzes the possible head and chest injuries, produced in a Hybrid III dummy model of a six-year-old child during a rollover test, while the child uses a passive safety system low-back booster (LBB). Vehicle seats and passive safety systems were modeled with a CAD (Computer Aided Design) software; later, all elements were analyzed using the finite element method (FEM) with LS-DYNA® software. The border conditions were established for each study, in accordance with the regulations of Federal Motor Vehicle Safety Standards (FMVSS), and following the FMVSS 213 standard for the mounting and fastening of the infant, the FMVSS 208 for the dolly methodology test with the vehicle rollover was performed, implementing such analysis under the same conditions for a vehicle Toyota Yaris 2010. The numerical simulations were performed during an interval of 1 second, obtaining data values for periods of 2 milliseconds. This paper examines the efficiency of the system; three case studies were carried out: Study I: vehicle seat belt (VSB); Study II: the LBB system was secured by the seat belt; Study III: the LBB system with ISOFIX anchorage. The values of decelerations for the head and thorax of the infant were obtained, as well as neck flexion and thoracic deflection. The main factor to reduce injuries during a rollover accident is the correct anchorage of the LBB, and this is achieved with the ISOFIX system, since it prevents the independent movement of the LBB, unlike when it is fastened with the seat belt of the vehicle. The results show low levels of head and chest injury when ISOFIX is used because of reduced thoracic deflection during infant retention.

Rollover prevention and path following control of integrated steering and braking systems

In the process of preventing rollover, the expected path of the driver to achieve better anti-rollover effect is often ignored, which may lead to the deviation of vehicle from the original path. Aiming at this problem, this paper considers both anti-rollover and path tracking performance, and proposes an integrated controller based on active steering and active braking. On the one hand, it can reduce the lateral acceleration and rollover risk by restraining the front wheel angle as tracking the driver’s expected path. On the other hand, through reasonably distributing the braking force of the four tires, it can offset the additional yaw moment caused by uneven distribution and reduce the impact on vehicle trajectory as the risk of rollover occurs. In addition, an improved index of rollover is put forward to give early warning to the future moment and to prevent rollover accident effectively. Simulation and hardware-in-the-loop test results show that the proposed integrated controller can ensure that the vehicle tracks the expected path well and achieves rollover prevention effectively.

Trajectory Optimization for Falsification:A Case Study of Vehicle Rollover Test Generation Based on Black-box Models

In this paper, we consider optimization of trajectories for automotive vehicle rollover testing. In particular, worst-case trajectories that are most likely to cause rollover accidents are determined through trajectory optimization. Our approach combines online local-model identification and gradient-based input update, and can be applied to black-box type models, e.g., a high-fidelity vehicle dynamics model given as a simulation code and not as an explicit set of equations. With our approach, a library of worst-case trajectories corresponding to different operating conditions (e.g., vehicle mass, road surface conditions, etc.) can be constructed and subsequently used in hardware tests.

Design and analysis of a polyamide – steel hybrid A-pillar for increased vehicle roof structural integrity in rollover accident scenarios

In a world where motor vehicles are the primary means of personal transportation, accidents have become common. One of the accident modes of note are rollover accidents which in most instances deals with the roof crush scenario. In roof crush, the A-pillar structures would have failed to a certain degree if not completely. In this research ways to strengthen the roof structure, in particular the A-pillar structure are sought through the application of Polymer-Metal Hybrid materials to the A-pillar design. The Polymer-Metal Hybrid Material is designed from material selection to configuration optimisation using design parameters derived from rollover accident scenario information as well as vehicle Body-in-White manufacturing processes. The hybrid material designed was constituted of directly bonded 43% glass filled polyamide 6/6 and dual phase 980 High Strength Steel. Analyses on the application of the design material and effectiveness of its optimised configuration are carried out through non-linear stress analysis simulations and Multi-Objective Genetic Algorithm optimisation techniques. Results point to the assertion that application of the hybrid material design can attain up to a 15% weight saving and attains with marginal stiffness performance gains. However, the strength performance of the hybrid material design shows that the design excels in withstanding forces stresses greater than the All-steel member by an order of nearly 2.

Signalization options to improve capacity and delay at roundabouts through microsimulation approach: A case study on arterial roadways in Ghana

Roundabouts are very useful when flows are balanced but can have operational challenges when flows increase. Most roundabouts on arterial roadways in Ghana experience recurring congestion during peak traffic. The four roundabouts between Ejisu Municipality and Asokwa Municipality on the N6 highway are typical of the situation found on arterials countrywide. They experience recurring long queues and delays during the peak hours and over-representation of truck rollover accidents. In Ghana, historically, most roundabouts with capacity problems have been developed into interchanges at very high cost without consideration of other effective at-grade configurations. When roundabouts are signalized, various configurations can be explored to enhance capacity while preserving the safety benefits. Using simulation techniques, various configurations and design options were tested for their effectiveness at two of the roundabouts, located at KNUST police station and Ejisu, with similar demand and high left turning volumes. The objectives of this study were to a) evaluate the performance of the selected roundabouts on the corridor; b) explore alternative intersection configurations to improve capacity and delay. Using video data collection techniques, 2-h time stamped footages of AM and PM peak traffic flows were captured for two days. Geometric design parameters of the existing roundabouts, queue lengths, travel times, and approach flows were also captured. VISSIM models of the selected roundabouts were developed and calibrated for the baseline conditions. Signalized unconventional roundabout configuration, with a phase for major road through traffic were simulated and assessed for capacity, delay and queue length. The results showed that signalized roundabout intersections effectively increased capacity by as much as 50% in some cases, reduced delay and queue length significantly, and maintained the benefits of roundabouts including safety. The performance could be further enhanced by introducing separate left turn phases to reduce conflicts or through a right turn U-turn (RTUT) concept. • The study explored the operational performances of a proposed signalised unconventional roundabout through microsimulation. • The proposed intersection layout provided two lanes through the central island for the through traffic on the major road. • The signalised roundabout concept was comparatively a better improvement option to alleviate congestion. • A right turn U-turn (RTUT) concept was recommended to further enhance the performance of the signalised roundabout option.

Statistical Overview of Factors Influencing Traffic Accidents Severity On El-Brega Coastal Freeway in Libya

Background: Globally, Road Traffic Accidents (RTAs) are one of the significant causes of fatality and injury. In Libya, RTAs have resulted in disabilities and were the third leading cause of death. However, there is a lack of information on RTAs and road safety in Libya. Objective: The present study aims to fill the knowledge gap by performing a statistical analysis to identify the factors associated with road accident severity in El-Brega Coastal Freeway. Methods: RTAs data extracted from police investigation reports in Ajdabiya Municipality for the period from 2001 to 2010. Then descriptive analysis and Binary logistic regression model (BLM) are applied to analyzing the data. Results: Descriptive analysis results showed that between 2001 and 2010, approximately 45% of RTAs in Ajdabiya Municipality occurred on El-Brega Coastal Freeway, and more than 1225 individuals lost their lives or sustained injuries in these RTAs. Furthermore, Sixty-two percent (n = 137) of those who died in accidents were from the 20–45 age group. BLM Results concluded that only eight predictors have statistical significant with accident injury severity. Five of them increase the likelihood of injury severity. A head-on collision is the prime influence factor to increase injury severity odds, followed by high-speed driving, Weekends, horizontal curves, and driver’s age. While accident injury tends to be less severe with the other predictors like rollover collision, rear-end collision, and accidents involving animals. Conclusion: Thus, implementing the use of seat-belt and speed control regulations, with activating ambulance services are the urgent countermeasures to enhance road safety.

Theoretical-experimental study of the repair of steel bus structures after rollover

The aim of this work is to study the resistance of bus and coach steel structures repaired by mechanical straightening after a rollover accident, analysing the change in the Moment-angle characteristic curve and quantifying the loss of energy absorption capacity. Bending tests have been carried out on rectangular section steel profiles of small thickness, simulating the damage caused by a first accident, as well as the repair by straightening and subsequent deformation in a second accident. On the basis of these tests, the loss in energy absorption capacity has been calculated and samples have been obtained for micrographs to observe how large deformations affect the microstructure. The results have shown significant differences in the behaviour of repaired profiles, as well as a loss in energy absorption capacity of over 30% in some cases. Finally, a methodology is proposed to calculate by means of F.E.M. models the Moment-angle curve of these types of profiles after a post-accident repair, with significant correlation between tests and models based on the validation metrics Cora and Sprague and Geers.

Coupling Simulation of an Impact-Induced Rollover Accident and Evaluation of Curtain Airbag Effectiveness

The causes of fatal and serious injuries in rollover accidents have yet to be fully identified. This study aimed to reconstruct a complex accident, based on both video analysis and vehicle coupling simulation. Besides, the major fatal injury causation and curtain airbag’s effectiveness were analyzed. The coupling model, including finite element tire and multi-body vehicle body, was developed to estimate the vehicle trajectory. A validated curtain airbag (CAB) module, was introduced for occupant protection effectiveness evaluation. The vehicle trajectory from the simulation correlated well with that from video recordings and simulation result indicated that passenger’s head contact with road (maximum contact force 9834.9[Formula: see text]N) was assumed to be the main reason of the victim death. After introducing the CAB, the maximum head acceleration was reduced from 129.1[Formula: see text]g to 24.9[Formula: see text]g, and the neck Fz was reduced by 80.0% as well. The coupling simulation method turned out to be efficient to reconstruct certain complex accident case. Such study is beneficial for further similar accident reconstruction and restraint system evaluation.

Tractor Rollover Protection: Is the Incorrect Use of Foldable Rollover Protective Structures Due to Human or to Technical Issues?

To identify the critical behaviors that may hinder the correct use of foldable rollover protective structures (FROPS) on tractors and to explore the influence of user factors and FROPS technical characteristics. FROPS are effective in preventing fatal injuries in rollover accidents if they are in the upright position. However, many farmers leave FROPS folded down. Twenty farmers and sixteen models of tractors were involved in the study. Operators were observed while raising the FROPS, and the observed behaviors were correlated with user factors and FROPS technical features. In the initial rotation of the FROPS, higher lowered roll-bar to ground distance and FROPS pivot-pin to ground distance required more awkward and unbalanced postures (p = .02 and p = .01, respectively). When rotating the FROPS in upright position, smaller stature of the participants and higher FROPS pivot-pin to ground distance were significantly correlated with using the tractor's rear 3-point lower links as a supporting surface (p = .01 and p = .02, respectively). FROPS might be revised considering users' comfort in use and anthropometric variability, to improve reachability, avoid risky behaviors, and enhance FROPS operation. Technical solutions to enhance FROPS accessibility may be developed, particularly by providing safe surfaces to support operators and highlighting the grasping points. Further best practices and information on correct gestures to handle the FROPS should be included in the tractor manual.

Dynamic Stability and Control of Tripped and Untripped Vehicle Rollover

Vehicle rollover accidents have been a serious safety problem for the last three decades. Although rollovers are a small percentage of all traffic accidents, they do account for a large proportion of severe and fatal injuries. Specifically, some large passenger vehicles, such as large vans, pickup trucks, and sport utility vehicles, are more prone to rollover accidents with a high center of gravity (CG) and narrow track width. Vehicle rollover accidents may be grouped into two categories: tripped and untripped rollovers. A tripped rollover commonly occurs when a vehicle skids and digs its tires into soft soil or hits a tripping mechanism such as a curb with a sufficiently large lateral velocity. On the other hand, the untripped rollover is induced by extreme maneuvers during critical driving situations, such as excessive speed during cornering, obstacle avoidance, and severe lane change maneuver. In these situations, the forces at the tire-road contact point are large enough to cause the vehicle to roll over. Furthermore, vehicle rollover may occur due to external disturbances such as side-wind and steering excitation. Therefore, it is necessary to investigate the dynamic stability and control of tripped and untripped vehicle rollover so as to avoid vehicle rollover accidents. In this book, different dynamic models are used to describe the vehicle rollover under both untripped and special tripped situations. From the vehicle dynamics theory, rollover indices are deduced, and the dynamic stabilities of vehicle rollover are analyzed. In addition, some active control strategies are discussed to improve the anti-rollover performance of the vehicle.

Evaluation of Crush Protection Devices for agricultural All-Terrain Vehicles

Statistics show that there are a large number of All-Terrain Vehicle (ATV) rollover-related injuries and fatalities in the agriculture sector. Properly designed and installed Crush Protection Devices (CPDs) can potentially decrease the operator injuries in an ATV rollover accident. The CPD of a vehicle protects the operator by increasing the crush protection zone (CPZ) under the overturned vehicle. Several operational and safety evaluation criteria for ATVs equipped with CPDs were developed in this study. Some of criteria were evaluated in previous studies but required further assessment. Previous studies regarding the CPD performance in ATV rollover accidents were reviewed. Also, several factors related to operational and safety criteria for three designs of CPD (Quadbar, Lifeguard, and Air-Quad) mounted on 13 ATV models were measured. Factors include the shape and volume of the rear and side CPZ and the increase in the height of the centre of gravity height when the ATV is equipped with a CPD. The results of this study showed that the installation of a CPD increases the CPZ volume compared to the baseline ATV, in the event of a rollover accident. The AIR-Quad, Quadbar, and Lifeguard systems increased the rear CPZ volume with an average of 0.48 m3 (111% increase), 0.39 m3 (92% increase), and 0.15 m3 (35% increase), respectively, compared to the average CPZ of a baseline ATV which is 0.44 m3. Also, a CPD increases the distance between the seat reference point and the ground surface during a rollover accident.

Rollover risk assessment and automated control for heavy duty vehicles based on vehicle‐to‐infrastructure information

A novel rollover risk assessment and control approach is presented. First, a road-vehicle-environment coupling model with various random parameters, including wind velocity and road curvature, is developed. Second, a safety margin is defined to divide the safe and dangerous domains in the parameter space. Then, the first-order reliability method (FORM) approximation is developed to evaluate the probability of rollover accidents using a vehicle dynamics model. Finally, the state-space equation of automated control system is built based on model prediction control (MPC). With the front wheel steering angle and four wheels' braking torque as the control inputs, the additional yaw moment is used to prevent vehicle rollover. The control system model is implemented on the Trucksim/Simulink simulation platform. The results show that the automated control system proposed can prevent vehicle rollover effectively and enhance the driving performance of the vehicle. This study suggests that the presented rollover risk assessment and control methodologies can effectively estimate the rollover risk for HDVs under complex environments, whereas doing so would be very difficult with sensors alone.

Traumatic rupture of the Meckel’s diverticulum due to a blunt abdominal trauma caused by a tractor rollover

Introduction: The Meckel’s diverticulum is a common congenital anomaly of the gastrointestinal tract that rarely causes symptoms. Symptomatic patients usually present with haemorrhage, obstruction or inflammation of the diverticulum, however, perforation, specially following a blunt abdominal trauma is very rare. We present a rare case of an isolated diverticular rupture due to a crushing abdominal trauma. Case Report: A 36-year old male presented with abdominal pain after a rollover accident, in which his abdomen got stuck underneath the structure of an industrial tractor. Initial physical examination showed bruises on the hypogastric region without signs of peritonitis or haemodynamic instability. Image examination didn’t show clear signs of intraperitoneal trauma. Due to the worsening of the patient, an exploratory laparotomy was performed and revealed blood and faecal content in the peritoneal cavity, consequence of a Meckel’s diverticulum rupture. Conclusion: The rupture of the Meckel’s diverticulum is a rare cause of peritonitis following blunt abdominal trauma. A prompt surgical decision with the excision of the diverticulum is essential to control de damage in this patients

The safety analysis of transportation vehicles carrying prefabricated units under the action of gusts

The prefabricated-unit industry has developed rapidly and the safety of vehicles carrying prefabricated units has received extensive attention. In order to evaluate the safety of vehicles carrying prefabricated units under the action of gusts, the roughness of road surfaces was simulated by the sinusoid superposition method. Furthermore, the wind load was simulated by the harmonic synthesis method. The analysis model of the 13-DOF vehicle was established, and the wind-vehicle-road system was formed. In addition, the safety of the vehicles carrying prefabricated units under gusts was analyzed. It is demonstrated that when a vehicle encounters a sudden gust during driving, lateral deviation of the body will occur. The contact force on the windward side wheel will drop sharply and the wheel is easy to get off the ground, which decides whether a rollover accident happens or not. It sheds light on the safety analysis for ultra-wide and overweight vehicles under gust action.

Simulation Study of Rollover Accident of Wheel Loader during Steep Turn

Simulation Study of Rollover Accident of Wheel Loader during Steep Turn

LQR Anti-rollover Control of Active Suspension in Vehicle

In order to improve the ability of anti-rollover for vehicle, the paper established a 4 DOF vehicle rollover dynamics model, and proposed a LQR control strategy based on active suspensions for vehicle. Under the Matlab/Simulink, the simulations and the results show that the presented control scheme not only can reduce the roll angle and roll angular velocity, but also can improve the rollover stability of the vehicle, and reduce the possibility of vehicle rollover accident.

Tractor rollover fatalities, analyzing accident scenario

IntroductionIn many countries, traditional data sources for collecting injuries of workers covered by compulsory accident insurance have recently been integrated by new observatories whose results may differ. A comparative analysis of the Italian data collection systems related to fatal tractor accidents in agriculture was performed focusing on tractor rollover fatalities with the aim of analyzing the accident scenario. MethodData from the Operational Archives of the Italian Workers Compensation Authority (INAIL), which collects injuries of workers covered by compulsory accident insurance and those of the National Surveillance System (INAIL_ASL), which provides narrative text reports of work-related fatal accidents have been analyzed and compared to the information collected by the INAIL Observatory. The INAL Observatory was recently set up to complement the collection of fatal accidents involving agricultural machinery. Italian data were then compared to data available at an international level. Fatal tractor accidents vary considerably with respect to fatal accidents in agriculture, being 10.6 and 43.7% for the Operational Archives and Surveillance System, respectively. National Surveillance System records, implemented with narrative texts allowed the accident scenario to be defined. Results71.7% of fatal tractor-related accidents refer to non-ROPS equipped vehicles and of these, 26.5% involved machines originally mounted with a ROPS that had been removed or was inoperative in the folded-down position during the rollover event. Just one fatal event from a collapsed ROPS on the overturned tractor was recorded. It is interesting that 16.6% of fatal accidents involved a clear environmental factor. Practical applicationA campaign to train tractor drivers on the correct use of the combination ROPS and seatbelt can contribute to decreasing rollover events with fatal outcomes. Contemporarily a strict requirement to install ROPS and a seatbelt on tractors, combined to an official inspection at the farm level, can increase the chance of survival in a rollover accident.

The Importance of Friction Coefficient between Vehicle Tyres and Concrete Safety Barrier to Vehicle Rollover - FE Analysis Study

The most important mechanical factors in an impact scenario of a vehicle into a concrete safety barrier are vehicle speed, the impact angle, the static stability factor of the vehicle as well as the concrete safety barrier design and conditions. Concrete safety barriers (CSB) are primarily designed to minimize vehicle damage by allowing the vehicle to be lifted when riding up on the lower slope and then redirected back on to the road. In some cases, though, the vehicle-CSB contact might end up with a rollover often with fatal consequences. To reduce the rollover risk, different concrete barrier shapes were designed in the past while omitting the importance of the friction coefficient between the tyre and barrier. Therefore, the aim of this paper is to research and emphasize the importance of the friction coefficient between the vehicle tyres and the CSB in rollover accidents. For that purpose, a series of Finite Element analyses were performed using different values of the friction coefficient between the vehicle tyres and the CSB. Experimental measurements of the coefficient of friction between the rubber and CSB blocks of different surface were additionally performed in dry and wet conditions in order to examine the real onsite friction characteristics. The results show that the coefficient of friction can have a crucial impact in vehicle rollover scenarios and should therefore be kept as low as possible by the concrete safety barriers manufacturers and maintainers.

Explicit controller of a single truck stability and rollover mitigation

This study’s aim was to enhance the maneuverability safety in the coordination of active rear steering and differential braking control for untripped rollover prevention, which performs a panic lane change maneuver to bypass the obstacle encountered in the path. In avoiding rollover accidents, there are several guidance preventions, such as to secure the vehicle from the intention of the driver and to position the vehicle in the actual lane. A crosswind effect is also found to be a crucial factor since this may cause other accidents. Therefore, there is a need to monitor the driver’s actual path and maintaining the stability of the vehicle along the desired path in order to avoid rollover accidents. We extended the analysis of Yakub and Mori (2015) [1], by suggesting an explicit model of predictive control, which includes an active rear steering and braking control for each wheel. Our main focus was on the general trade-off between rollover prevention and path tracking. The effectiveness of the explicit control model invented for this study was measured and validated by the simulation results for a heavy vehicle proposed in this research.