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Development of a continuous motorcycle protection barrier system using computer simulation and full-scale crash testing
Abstract
Road restraint systems are designed to minimize the undesirable effects of roadside accidents and improve safety of road users. These systems are utilized at either side or median section of roads to contain and redirect errant vehicles. Although restraint systems are mainly designed against car, truck and bus impacts there is an increasing pressure by the motorcycle industry to incorporate motorcycle protection systems into these systems.
In this paper development details of a new and versatile motorcycle barrier, CMPS, coupled with an existing vehicle barrier is presented. CMPS is intended to safely contain and redirect motorcyclists during a collision event. First, crash performance of CMPS design is evaluated by means of a three dimensional computer simulation program LS-DYNA. Then full-scale crash tests are used to verify the acceptability of CMPS design. Crash tests were performed at CSI proving ground facility using a motorcycle dummy in accordance with prEN 1317-8 specification. Full-scale crash test results show that CMPS is able to successfully contain and redirect dummy with minimal injury risk on the dummy. Damage on the barrier is also minimal proving the robustness of the CMPS design. Based on the test findings and further review by the authorities the implementation of CMPS was recommended at highway system.
... None of the MPS demonstrated any adverse impact on the injury risk to passenger car occupants. Atahan et al. (2018) utilized finite element modelling with LS-DYNA to test different design features of a continuous MPS. Based on the results from these evaluations, two full-scale crash tests were performed using the same test specifications as in Baker et al. (2017). ...
... Thus, the crash tests show promising results, but more research is needed to understand injury risks that MPS pose to motorcyclists impacting in an upright or alternative position (Baker et al., 2017), and how MPS perform when implemented with a radius (Atahan et al., 2018). In addition, more research is required to evaluate how MPS perform in real world conditions (Baker et al., 2017). ...
A report on Powered two wheeeler safety. Presenting the outcome and synthesised priority actions to increase safety, from the ITF workshop "Riding in a safe system".
... Few other modeling techniques have also been employed including spatiotemporal analysis 31,32 , log-linear model 33 , latent class analysis 34 , Bayesian multivariate crash frequency model 35 , Bayesian Network 36 , multiple correspondence analysis 37 , taxicab correspondence analysis 38 , machine learning 28,39 , and data mining 40,41 . Studies involving deep learning 5 , computer simulations, and full-scale crash testing 42 focused on innovative approaches to motorcycle crash analysis and safety interventions. A deep learning framework, DeepScooter, was developed to predict crash severities with high accuracy, revealing that rider ejection, curved roadways, and weekend crashes are associated with higher injury risks 5 . ...
Motorcyclists face an increased risk of injury severity at curved roadway segments due to a wide range of factors. Given the complex and evolving nature of factors influencing motorcyclist injury severity on curved roadway segments, there is a need for research that not only captures these contributing factors dynamics but also considers temporal variations and unobserved heterogeneity. The study used mixed logit models to analyze 8815 motorcycle crashes that occurred on curved segments in Texas between 2017 and 2022. Several normally distributed random parameters were identified, including clear weather, fixed objects, a 40–60 mph speed limit, White ethnicity, and riders aged 25–54 years old. Average marginal effects indicated increased fatal injury likelihood during cloudy weather, on marked lanes, roads without median, and collisions with fixed objects. Consistent factors affecting fatal injury severity across yearly models included cloudy weather and fixed-object collisions (increasing), daylight (decreasing), and riders aged 15–24 (decreasing). Interestingly, darkness in 2020 showed reduced fatal injury likelihood, likely due to lower traffic volumes and increased rider caution during the COVID-19 pandemic, contributing to less severe crash outcomes. These findings emphasize the need to consider temporal variations to understand changing risk factors and dynamics in motorcycle injury severity on curved road segments.
... A study presented the development of a motorcycle barrier and evaluated crash performance to enhance road safety by redirecting motorcyclists during collisions (12). The results aided in addressing growing motorcycle safety concerns within road restraint systems. ...
Roadside and median barriers have proven effective in preventing crashes; however, a significant number of crashes still occur that involve road barriers across United States. This study focuses on analyzing the factors related to barrier crashes across Texas. The dataset includes 63,475 crashes involving road barriers and covering six years of crash data (2017–2022). Using cluster correspondence analysis (CCA) data mining approach, the study identifies six different clusters of crashes. Each cluster identifies factors contributing to barrier-related crashes. Before implying the CCA, variable importance analysis is also performed to identify the significance of the variables. The analysis highlighted that dry road surface conditions and clear weather are highly associated with high-speed crashes. Driver distraction and absence of traffic control devices can attribute to the crashes on roads with lower speed limits. Moreover, along with other factors, adverse weather conditions are also found to be a contributing factor that can influence the crash frequency and type of crashes. The analysis also implies that non-complex crash type related to a single vehicle are highly correlated with barrier crashes. The study concludes by making several policy-making implications to assist the transportation planners in reducing the frequency and severity of barrier-related crashes.
... Li et al., 2019), log-linear model (Haque et al., 2012), latent class analysis Gkritza, 2014, 2014), Bayesian multivariate crash frequency model (Cheng et al., 2017), Bayesian Network (Das et al., 2023), multiple correspondence analysis (Jalayer and Zhou, 2016), taxicab correspondence analysis (Das, 2021), machine learning Jiang, 2020, 2019b), and data mining (Cunto and Ferreira, 2017;Kashani et al., 2014). Studies involving deep learning (Das et al., 2018), computer simulations, and fullscale crash testing (Atahan et al., 2018) focused on innovative approaches to motorcycle crash analysis and safety interventions. A deep learning framework, DeepScooter, was developed to predict crash severities with high accuracy, revealing that rider ejection, curved roadways, and weekend crashes are associated with higher injury risks (Das et al., 2018). ...
... However, barriers represent a much greater fatality risk to motorcyclists than to car occupants; 15 times in Europe and 80 times for steel guardrails in the United States [26,27]. Although restraint systems are mainly designed against car, truck, and bus impacts, the motorcycle industry has increased pressure to incorporate motorcycle protection systems into these systems [28]. Fatality risks due to conventional steel and concrete barriers are shown in Fig. 5. ...
Roadside barriers have been one of the main contributors to reducing fatal traffic accident severities. There is limited knowledge about the potential for using natural/waste materials for roadside barrier applications. This paper aims to develop a novel hybrid roadside barrier type by using timber and waste materials (slag and tire) together and to observe the performance. In this regard, pendulum crash tests were conducted and deformation, working width, and severity performance of each hybrid barrier type were evaluated following EN 1317 road restraint systems standard. Experimental results revealed that hybrid barriers produced with waste materials can be alternative to conventional barriers. They can be recommended to place, especially in scenic, mountainous, and historical roadsides due to their aesthetic design and environmentally friendly features. This is the first step towards enhancing innovative hybrid barriers and will serve as the basis for the next step, full-scale crash tests. Outcomes of this study will encourage the utilization of different waste materials in the production of roadside barriers in future studies and contribute to the diversification of utilization areas of waste materials.
... However, since these barriers are new compared to conventional guardrails, the design needs to be improved. By using dummy, real crash tests, and finite element simulations for the development and design of motorcycle barriers, studies such as reducing the impact of barriers, improving the orientation angles and protective clothing during impact were carried out within the scope of the standards (Deck et al. 2003;Bosch 2006;Ghajari, et al. 2010;Bambach and Grzebieta 2014;Mantaras and Luque 2015;Atahan et al. 2018). ...
Longitudinal barriers are considered as passive safety systems designed to shield hazards located at roadsides against motor vehicle impacts. Since these barriers are manmade obstacles, they also pose a threat to drivers using the road. Recent motorcyclist accidents with longitudinal barriers have proven that a particular barrier successfully protecting vehicle occupants may wound or kill motorcyclists due to its components. For this reason, sharp and blunt edges in steel longitudinal barrier parts, such as posts are usually shielded against contact from unprotected motorcyclists during a high-speed impact event. In recent years, more longitudinal barriers have been designed with motorcyclists in mind and these motorcycle protection barriers have become wide spread especially on urban high-speed roads. However, since the development of these barriers are fairly new compared to conventional longitudinal barriers, there is limited guidance on their design criteria, such as thickness, geometry, connections. For this purpose, this paper intends to provide an artificial neural network metamodeling-based design optimization methodology to an existing continuous motorcycle protection barrier design to make it more competitive in terms of weight and thus, cost. As a result of this study, the optimized barrier has become 34% more economical compared to its original design while its protection level remained intact.
... Several studies identified powered-two-wheeler (PTW) ROR crashes as a major safety issue. Furthermore, motorcyclists are dramatically overrepresented in the fatalities resulting from guardrail impacts (Atahan et al., 2018;Daniello and Gabler, 2011;Jama et al., 2011;Russo and Savolainen, 2018). EuroRAP (2008) reported that PTW drivers are 15 times more likely to be killed than car occupants because of collision with roadside barrier. ...
The main objective of this paper was to analyse the roadway, environmental, and driver-related factors associated with an overrepresentation of frequency and severity of run-off-the-road (ROR) crashes. The data used in this study refer to the 6167 crashes occurred in the section Naples–Candela of A16 motorway, Italy in the period from 2001 to 2011. The analysis was carried out using the rule discovery technique due to its ability of extracting knowledge from large amounts of data previously unknown and indistinguishable by investigating patterns that occur together in a given event. The rules were filtered by support, confidence, lift, and validated by the lift increase criterion. A two-step analysis was carried out. In the first step, rules discovering factors contributing to ROR crashes were identified. In the second step, studying only ROR crashes, rules discovering factors contributing to severe and fatal injury (KSI) crashes were identified. As a result, 94 significant rules for ROR crashes and 129 significant rules for KSI crashes were identified. These rules represent several combinations of geometric design, roadside, barrier performance, crash dynamic, vehicle, environmental and drivers’ characteristics associated with an overrepresentation of frequency and severity of ROR crashes. From the methodological point of view, study results show that the a priori algorithm was effective in providing new information which was previously hidden in the data. Finally, several countermeasures to solve or mitigate the safety issues identified in this study were discussed. It is worthwhile to observe that the study showed a combination of factors contributing to the overrepresentation of frequency and severity of ROR crashes. Consequently, the implementation of a combination of countermeasures is recommended.
... The model of HYBRID III was successfully used in many other safety assessment research studies mainly in crash analysisGhajari et al. (2009), Ghajari et al. (2011 but also in other physical scenarios where assessment of human injury was neededBabu et al. (2018),Bochorishvili et al. (2019),Nilakantan and Tabiei (2009), Williams andFillion-Gourdeau (2002). After the approval of CEN/TS 1317-8 at 2012 it is also widely used for evaluation of safety performances of different restrained systems according to the specified requirementsAtahan et al. (2018),Mantaras and Luque (2005),Miralbes (2013), ...
The number of registered motorcycles in Europe is continuously growing. This increases the risk of motorcyclist-traffic barrier interaction potentially leading to serious injuries or death. On the other side, a fundamental weakness of the road barriers in Europe is that they were designed before the approval of the technical specification CEN TS 1317-8 for motorcyclist protection in 2012 after which numerous protective systems were designed and tested. This paper presents the results of numerical simulations of the HYBRID III dummy impact into the C-beam post of a safety barrier with and without HDPE (High-Density Polyethylene) protection. For both models, the numerical tests were performed with different dummy positions with respect to the longitudinal axis of the barrier and different impact velocities. The results comparison showed that HDPE protection effectively decreases injury parameters at low impact velocities up to 30 km/h, whereas its efficiency at higher impact velocities is limited.
... Consequently, the outcome of tests using older vehicles may not be representative of real impacts entailing a modern vehicle. It is clear that, in order to ensure the safety of Europe's roads, some changes must be made to the current regulation, in parallel with the ongoing activities towards the transformation of the technical specification UNI CEN/TS 1317-8:2012 into a full European standard to properly test RRSs for motorcyclist safety (García et al., 2009), and towards incorporating motorcycle protection systems such as steel guardrail barrier systems with posts (Atahan et al., 2018) to decrease one of the prime reasons for motorcyclist fatalities (Delhaye and Marot, 2015). ...
The safety of roadside restraint systems in Europe is ensured by the EN 1317 regulation. The ability of the barrier to mitigate injury to the occupants of vehicles is tested according to two occupant injury metrics: Acceleration Severity Index (ASI) and Theoretical Head Impact Velocity (THIV). Both metrics aim to predict occupant head injury from vehicle kinematics, despite the potential to easily measure actual head kinematics from instrumented Anthropomorphic Test Dummies, a non-instrumented version of which is already required according to the regulation. Retrospective data provided by AISICO S.r.l. for 33 certificated barrier tests, where acceleration of the dummy's head had also been recorded, were re-analysed. ASI and THIV were compared with Head Injury Criterion (HIC15) and Neck injury Criterion (Nij), as well as corresponding Real Head Impact Velocity (RHIV) values. Three barriers presented HIC15 values above the threshold used in crashworthiness testing, two of which corresponded to fatal injury according to the Abbreviated Injury Scale. One barrier presented an Nij value corresponding to a 30% risk of neck injury. RHIV values were above the regulation threshold in 15% of tests, but were not significantly different from the corresponding THIV values. It was concluded that vehicle kinematics do not accurately predict head kinematics during barrier testing. The presented data indicate the current EN 1317 regulation was not capable of detecting all potential dangerous outcomes, with the potential to underestimate occupant risk. Further investigation is necessary to devise suitable indices based on actual head and neck data. These data would be obtained from a dummy instrumented with both a head accelerometer and neck load cell and, possibly, a gyroscope. To consistently test the true worst-case scenario, the tested side window should be closed and non-reinforced.
... Besides these standards and guidelines, continual efforts by researchers on the evaluation of the crash performance of guardrails allow the modification and advancement of the precedent guardrail design. Thereafter, many refined guardrails have been developed and used to address, particularly, the roadside safety concerns [12][13][14][15][16]. Other special rails, e.g., a portable water-filled road safety barrier system used in temporary zone, were studied to enhance the road safety in the construction zones [17][18][19]. ...
In this study, a new movable median guardrail is proposed to overcome the structural defects of and to improve the low anti-collision performance of two conventional central/ median guardrails comprising of the concrete and W-beam. The design parameters of this movable median guardrail are optimized based on the uniform design method and a linear weighted combination method in accordance with the requirements given in the National Cooperative Highway Research Program (NCHRP) Report 350. This proposed guardrail is systematically evaluated in terms of its energy absorbing capacity, vehicular acceleration, post-impact trajectory of the impacting vehicle, and behavior of the guardrail upon impact through a three dimensional computer simulation using LS-DYNA code. In the evaluation process, performance comparisons of the moveable median guardrail are made with the concrete and W-beam guardrails. The results shows that the performance of the proposed movable median guardrail is superior as compared to the conventional concrete and W-beam guardrails as it offers: a higher level of crash performance is exhibited, the occupants of the impacting vehicle is better protected, and the impacting vehicle exhibits better post collision stability.
... 2.10. Development of a continuous motorcycle protection barrier system using computer simulation and full-scale crash testing Atahan et al. (2018) present a protection barrier system aimed at improving the safety of motorcyclists. The authors present the motorcycle protection barrier system and assess its crash performance using both computer simulations and full-scale crash testing. ...
After the guardrails are designed, the structural adequacy and safety criteria are determined by the relevant standards and full-scale crash tests. One of the widely used standards is European Norm 1317 (EN1317). Guardrail systems generally consist of rails and posts. The guardrails are more rigid around the posts, which are mounted on the ground or embedded in soil at certain intervals. Therefore, it is important for driver/passenger and roadside safety to determine the most critical point in terms of structural and safety performance and design according to the most unfavorable situation. With this motivation, in this study, the effect of different impact points on the structural and safety performance of the H1W4 guardrail was investigated by finite element (FE) analysis. For this purpose, first of all, the finite element models of the H1W4-A system were calibrated and validated with real crash test data. Then, with the help of the validated models, analyses were completed for different impact points as 0.5, 1.0, 1.5 and 2.0 meters with a half-meter difference for the standard 2-meter post spacing. In the light of the measured safety parameters such as Acceleration Severity Index (ASI), Theoretical Head Impact Velocity (THIV) and structural performance criteria such as working width (W) and exit angle (α), the critical impact point for the guardrail was determined. Contrary to what is generally known, crashing vehicles into flexible points (0.5 and 1.0 m) rather than impacting rigid points (1.5 and 2.0 m) creates a more negative situation in crash tests.
Bridge guardrails play an important role in vehicle safety. Bridge guardrails frequently use concrete guardrails and beam-column guardrails. However, they have the disadvantages of poor buffering effect, being difficult to replace after damage, and being easy to cause damage to the bridge. A novel style of assembled rolling guardrail is presented in light of these drawbacks. In this research, a vehicle-guardrail collision numerical model is built in LS-DYNA. Subsequently, the performance of Beam-column guardrail (B-C.G), Assembled Guardrail (A.G), and Assembled rolling guardrail (A-R.G) is evaluated. The findings demonstrate that the A-R.G satisfies the specification’s requirements, can increase the construction efficiency, and, in contrast to the conventional beam-column guardrail, essentially does not cause damage to the bridge. Additionally, it performs better than the other two types of guardrails. Compared with the A.G and the B-C.G, the A-R.G has better energy absorption effect, steering effect. Moreover, the A-R.G significantly reduces the acceleration of the vehicle. The A-R.G dramatically lessens guardrail and vehicle damage, enhances the guardrail’s structural integrity, and increases passenger safety.
Road restraint systems-RRS are passive safety designs installed on roadsides to ensure the safety of errant vehicle passengers as well as pedestrians. The adequacy of these systems is assessed through full-scale vehicle crash testing for which evaluation criteria are determined by standards such as EN1317. Recently the same RRS is crash tested two times with two different 900 kg passenger cars and test results varied significantly. After a failed crash test instead of modifying the barrier test vehicle was replaced and the same test was repeated. It was surprising to see that the failed RRS this time satisfied the EN1317 evaluation criteria. Despite the use of the same mass vehicle in the crash tests, the different results obtained were a source of motivation for investigating the inadequacy of EN1317. In this study, the adequacy of the 900 kg vehicle criteria used in the determination of the safety parameters in the EN1317-TB11 test was investigated by creating validated finite element-FE models. After the FE analysis it was concluded that test vehicle properties, such as vehicle mass and velocity provided in EN1317 are deemed to be insufficient and more explicit vehicle selection parameters, given in the study, are needed to provide safer and more uniform crash testing results.
In Sweden there is an on-going process to formulate a national standard regulating the design of temporary traffic control devices used on pedestrian and bicycle paths. This paper presents results from simulated single-bicycle crashes with the purpose to create an understanding of how different features of such devices affect the risk of injuries among cyclists. A Hybrid II 50th percentile crash test dummy was placed in the saddle of a bicycle and crash tests, usually at 25 km/h, were performed. Eleven different types of road equipment were included, and different crash angles were applied, in a total of over 50 crash tests. The road equipment represented temporary traffic control devices of various kind commonly used in Sweden, but also some specifically designed for cyclists. The tests were documented with several video cameras at different angles. Slow motion pictures were analyzed with focus on mechanisms during impact and the following motion of the bicycle and the dummy. Observations regarding “body parts” in contact with the road equipment were of particular interest highlighting design features of importance such as height, smoothness of surfaces and energy-absorbing capacity. The tests show that all bicycle crashes into road equipment can cause injuries and thus the use of work zone material on bicycle paths should be avoided, if possible. Safety barriers designated to prevent cyclists from falling into a shaft must be high enough to do so and be anchored and linked together correctly to prevent them from falling and creating dangerous situations. Temporary traffic control devices should be flexible or energy-absorbing to moderate the injury outcome of a potential bicycle crash. Fences should have a fine meshed net construction to prevent bicycle handlebars from getting stuck. All road equipment should be designed without sharp edges as they could cause injuries to cyclists passing or crashing into the equipment.
To better evaluate the crash performance of the guardrail and reduce the number of actual vehicle crash tests, this paper uses mechanical analysis and finite element simulation technology to evaluate the typical movable guardrail and optimize the structure. It’s of great significance for improving the crashworthiness of this type of guardrail and enhancing its safety performance. Firstly, the vehicle-barrier mechanical model was established to calculate the vehicle collision force on the barrier. Secondly, the collision force model was used to calculate the collision of a 10-ton truck, and a finite element model of a typical movable barrier was established for a collision simulation. Finally, the wall thickness and column spacing were optimized according to the results. The simulation results show that the maximum lateral dynamic deformation of the barrier was 1,818 mm, which agrees with the actual vehicle test results (1,600 mm). When the wall thickness of the barrier increases by 2 mm, the maximum lateral dynamic deformation was 1,419 mm; When the spacing of strengthened columns was reduced to 15 m, the deformation was 1,364 mm; After optimization, the deformation was reduced by more than 20%, and the crashworthiness of barrier was improved obviously.
Traffic accidents such as vehicle collisions with bridge guardrails occur frequently. These accidents cause damage to the driver and the vehicle as well as the bridge. A new type of assembled anti-collision guardrail is proposed in this study. LS-DYNA is a nonlinear display dynamic analysis software used to evaluate the safety of a new type of assembled anti-collision guardrail. A specific, numerically analyzed model of vehicle–guardrail collision is established using LS-DYNA. The energy distribution–time curve of the vehicle collision process is obtained. After comparison with measured data from the vehicle collision test, the model of vehicle–guardrail collision is verified as being correct. Based on this, we analyze the process of a vehicle collision on the assembled anti-collision guardrail. The result shows that the assembled anti-collision guardrail proposed in this paper can better change the trajectory of a moving vehicle and can prevent the vehicle from falling off the bridge. From the car body collision results, the assembled anti-collision guardrail for bridges proposed in this paper can reduce vehicle damage and can protect the driver effectively. From the analysis of the main girder stress on the bridge, an anti-collision guardrail installed on an existing bridge will not cause damage to the main girder during a collision. In order to study the influence of the four parameters on the anti-collision effect, we carried out a comparative calculation of multiple working conditions. The results show that the new type of assembled anti-collision guardrail has good protective performance under different working conditions.
Background
Traumatic injuries remain one of the leading causes of death in the United States. Patients who survive traumatic injuries but return to the emergency department with repeat injuries are said to suffer from injury recidivism. Numerous studies have described trends in injury recidivism using trauma registry and survey data. To our knowledge, no prior study has leveraged electronic medical record (EMR) data to characterize injury recidivism. The EMR is potentially more comprehensive as it contains details of patients who visited the emergency department after injury but did not meet the criteria for inclusion in the trauma registry. Such injuries could be predictive of future recidivism. We therefore aimed to describe patterns of injury recidivism seen at a Level 1 trauma center using the EMR.
Methods
A retrospective review was conducted of all injury-related encounters between January 2016 and December 2019. Manual review was conducted of all recidivistic encounters with < 11 months between encounters to ensure the recidivistic encounter was not a sequela of the index visit. A general estimating equation logistic regression adjusted for age, race, sex, and insurance payor, estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the association between injury mechanism and odds of recidivistic encounter.
Results
A total of 20,566 index encounters was included during the study period. Of the 20,566 encounters, 7.6% (n = 1570) had a recidivistic encounter during the study period, half of which (n = 781) occurred within the first year of the index encounter. An over two-fold increased odds of recidivism was observed for blunt assault encounters (OR 2.53, 95% CI 2.03-3.15) and unintentional falls (OR 2.10, 95% CI 1.76-2.52). For both mechanisms, this increase was observed across the three years following the index encounter.
Conclusions
Our study found that patients with assault injuries have the highest odds of injury recidivism and assault-related recidivistic encounters. These results demonstrate the feasibility and utility of incorporating EMR data, and suggest that the development of targeted interventions focused on mitigating assault injuries, such as hospital-based violence intervention programs, should be considered in our region.
This paper describes the design and optimization of a safety barrier to protect motorcyclists in case of an accident, using, as a basis, rubber from used tires. The proposed motorcycle protection system (MPS) attempts increase motorcyclist protection in roads. But, at the same time, it offers a new alternative for the reuse of rubber from used tires, thus contributing to solving the environmental problem created by this type of waste. A first pre-design was proposed and tested according to UNE-135900 standard to evaluate the protection level against motorcyclist impact. Then, a finite element model of the new MPS and the dummy was used to reproduce the experimental impact tests. The model was validated and adjusted using data from material characterization tests and from a full-scale crash test carried out on a first prototype. The main design parameters influencing the deformation shape and the effort peaks obtained during impact were analyzed. Several modifications over the original barrier were made in order to meet the requirements of the standard. The new design of the barrier was tested, showing a lower severity than the initial prototype. In view of the results, the use of rubber appears to be technically feasible for the manufacture of these motorcyclist protection systems. However, some discordances were found between the injuries measured in the tests and the expected results obtained by simulation. High sensitivities to small variations in installation height and/or slight movements of the dummy’s head during the launch phase are pointed out as possible causes.
The impact of motorcyclists against the posts of the roadside barriers is one of the most frequently and harmful accidents. In order to avoid or minimize impact effects, different safety systems are being installed in many roads in the world. These safety systems should conform technical standards. European Technical Specification 1317-8 defines how it should be the testing procedure and placement of systems to prevent such accidents. The full-scale crash test with a dummy requires certain values not exceeded in neck forces, moments and Head Injury Criterion (HIC). This paper applies computer simulations (using Finite Element Method) in order to develop a virtual testing program to assess the safety system and evaluate the weaknesses of the mentioned standard.
Computer simulation of vehicle collisions has improved signi.cantly over the past decade. With advances in computer technology, nonlinear finite element codes, and material models, full-scale simulation of such complex dynamic interactions is becoming ever more possible. In this study, an explicit three-dimensional nonlinear finite element code, LS-DYNA, is used to demonstrate the capabilities of computer simulations to supplement full-scale crash testing. After a failed crash test on a strong-post guardrail system, LS-DYNA is used to simulate the system, determine the potential problems with the design, and develop an improved system that has the potential to satisfy current crash test requirements. After accurately simulating the response behavior of the full-scale crash test, a second simulation study is performed on the system with improved details. Simulation results indicate that the system performs much better compared to the original design.