Collision Incidents Research Articles

Contrast of concrete dynamic constitutive models and simulation of vessel–bridge collision

Long-span bridges are constructed to cross oceans or rivers. With the rapid growth of waterway transportation, vessel–bridge collision incidents now occur in large numbers. In order to provide better understanding of the actual responses of bridge structures under impact load, vessel–bridge collisions were simulated using the non-linear finite-element method. Four commonly used dynamic constitutive models of concrete are described in this paper. Two impact tests (a rigid ball striking a target concrete wall and a hammer striking a reinforced concrete (RC) beam) were simulated using LS-Dyna. It was found that the RC damage model was more suitable for simulating the inelastic responses of cracks than the other three models. Based on the RC damage model, a typical bridge substructure subjected to a 1000 dead-weight-tonnage vessel collision was numerically simulated. An empirical formula for estimating the maximum impact force was then developed. This formula, which considers the reinforcement ratio and the vessel collision velocity, is suggested for practical vessel–bridge design. The proposed empirical formula and the equations recommended in codes from different countries were compared and it was found that the assessment of vessel collision force using the new formula is significantly improved.

A Global Review of Vessel Collisions With Marine Animals

Concern about the effects of maritime vessel collisions with marine animals is increasing worldwide. To date, most scientific publications on this topic have focused on the collisions between large vessels and large whales. However, our review found that at least 75 marine species are affected, including smaller whales, dolphins, porpoises, dugongs, manatees, whale sharks, sharks, seals, sea otters, sea turtles, penguins, and fish. Collision incidents with smaller species are scarce, likely as a result of reporting biases. Some of these biases can be addressed through the establishment of species-specific necropsy protocols to ensure reliable identification of collision related injury, particularly blunt force trauma. In addition, creating a ship strike database for smaller species can assist in identifying the species most frequently involved in collisions, identifying high-risk areas, and determining species-specific relationships between vessel speed and lethal injury. The International Whaling Commission database on collisions with large whales provides a good example of this type of database and its potential uses. Prioritising the establishment of a species-specific necropsy protocol and a database for smaller species as well as the identification of high-risk areas for species other than large whales, would be a valuable step towards the mitigation of collisions with smaller species.

Severity of passenger injuries on public buses: A comparative analysis of collision injuries and non-collision injuries

Introduction: Although public buses have been demonstrated as a relatively safe mode of transport, the number of injuries to public bus passengers is far from negligible. Existing studies of public bus safety have focused primarily on injuries caused by collisions. Surprisingly, limited effort has been devoted to identifying factors that increase the severity of passenger injuries in non-collision incidents. Method: Our study therefore investigated the injury risk of public bus passengers involved in collision incidents and non-collision incidents comparatively, based on a police-reported dataset of 17,383 passengers injured on franchised public buses over a 10-year period in Hong Kong. A random parameters logistic model was established to estimate the likelihood of fatal and severe injuries to passengers as a function of various factors. Results: Our results indicated substantial inconsistences in the effects of risk factors between models of non-collision injuries and collision injuries. The severity of passenger injuries tended to increase significantly when non-collision incidents occurred due to excessive speed of bus drivers, on double-decker buses, in less urbanized areas, in winter, in heavy rains, during daytime, and at night without street lighting. Elderly female passengers were also found more likely to be fatally or severely injured in non-collision incidents if they lost their balance while boarding, alighting from, or standing on a bus. In comparison, the following factors were associated with a greater likelihood of fatal or severe injuries in collision incidents: elderly female passengers, standing passengers who lost balance, buses out of driver control, double-decker buses, collisions with vehicles or objects, and less urbanized areas. Practical Applications: Based on our comparative analysis, more targeted countermeasures, namely “4E” (engineering, enforcement, emergency, and education) and “3A” (awareness, appreciation, and assistance), were recommended to mitigate collision injuries and non-collision injuries to public bus passengers, respectively.

Driving Safety of Cognitively-Impaired Drivers Based on Near Collisions in Naturalistic Driving

Background:Controlled naturalistic driving for examining impacts of cognitive impairment on driving safety is rare.Objective:Evaluating the safety among drivers with mild cognitive impairment based on near collision incidents using naturalistic driving, and investigating its correlation with cognitive measures.Methods:Frequency of near collisions of 44 cognitively impaired [Age = 75.1(±6.7), MMSE = 25.5(±2.5)] and 19 control group drivers [Age = 72.5(±7.8), MMSE = 29.3(±0.8)] were obtained from two weeks of recorded driving. Survival time free of predicted collision based on a previously established near-collision to collision estimate ratio of 11 : 1, for 140 hours of driving exposure was calculated. Participants were also tested using Mini-Mental Status Examination (MMSE), Trail A, and Trail B. Spearman correlation and Cox survival analysis were conducted.Results:Near collision frequency per driving hour was correlated with MMSE (r = –0.258, p = 0.041). Survival analyses showed that cognitively impaired drivers might be prone to higher probability of having collision (p = 0.056) with a hazard ratio of 5.78 (p = 0.092). When all participants were combined, there was a significant difference (p < 0.017) in all the three cognitive measures between drivers with and without predicted collision, which were not significant within patient or control group alone (p > 0.186). Cox regression analysis showed MMSE as the only significant factor (p < 0.025) for survival time of predicted collision, but not age, gender, or driving experience.Conclusion:The association between driving critical events and cognitive measures suggests that some drivers with mild cognitive impairment might have an elevated driving collision risk compared to control drivers. Standard clinical cognitive measures may be reasonable predictors.

Criminal jurisdiction for ship collision and marine pollution in high seas-Focused on the 2015 judgement on M/V Ernest Hemingway case

ABSTRACTOn 16 January 2015, about 10 miles east of Busan, South Korea, Liberian container carrier, M/V Ernest Hemingway collided with Korean fishing boat, Geunyang-ho, and Geunyang-ho sank and two Korean nationals perished and about 600 liters of fuel oil on board Geunyang-ho spilt into the sea. M/V Ernest Hemingway’s crew escaped from the site without carrying out duties of rescue after the collision. The Busan District Prosecutor’s Office arrested and prosecuted M/V Hemingway’s second officer and an able seaman, Philippine nationals, for the criminal facts subject to judgement, violation of the Act on Aggravated Punishment, etc., of Specific Crimes, Professional Negligence resulting in ship sinking, and violation of the Marine Environment Management Act. Busan District Court pleaded guilty and sentenced fine for the violation of the Marine Environment Management Act, on the other hand, sentenced dismissal of public prosecution for the violation of the Act on Aggravated Punishment, etc., of Specific Crimes and professional negligence resulting in ship sinking due to lack of jurisdiction based on UNCLOS Article 97(1). Looking at the rulings and the annotations on this case, the main issues were whether South Korea has jurisdiction on ship collision incidents on the high seas as the state of the alleged victim’s nationality, and whether South Korea may exercise criminal jurisdiction over marine pollution caused by a ship collision on the high seas. This paper examines the decisions by the Courts and the main issues related with the case. Here is a summary of what has been reviewed in this paper: First, UNCLOS Article 97(1) is applicable for all criminal penalties of the captain and crew members concerning ship collision and other navigational accidents, without consideration on the intention, and can also be applied to intentions or attempts of illegal activities. Therefore, it can be applied to the events causing loss of life or serious injury (professional negligence resulting in deaths, running away after professional negligence resulting in deaths, etc.) and physical damage (professional negligence resulting in ship sinking, or ship damage, etc.) that were caused by ship collision, allowing priority over criminal jurisdiction exercised by the flag state and the state of the alleged offender’s nationality. Second, it is appropriate to interpret that the exclusive jurisdiction of the flag state on high seas as having a superior position against the jurisdiction of other states, not as having jurisdiction that excludes all other states. Therefore, in the M/V Hemingway’s case, it would be reasonable for our country to exercise complementary jurisdiction if the flag state and the state of the alleged offender’s nationality did not exercise criminal jurisdiction.Third, marine pollution accidents occurring in the high seas (EEZ of South Korea) should apply the relevant provisions of UNCLOS Part 12 regardless of the cause. The coastal state can institute proceedings when there are cases of marine pollution occurring in territorial seas or EEZ of the state and occurring outside of its EEZ but causing or being likely to cause damages to the state. For the lawsuit regarding the pollution accidents that occurred outside of national territories shall be suspended if the flag state institute proceedings on the same allegation within six months of the commencement of the lawsuit, and when the flag state ends the lawsuit, the suspended lawsuit is also automatically terminated. South Korea is eligible to file a lawsuit on the M/V Hemingway’s case, and because the flag state did not file a suit within six months, the judgement of the South Korean Court is considered to be valid. Fourth, while the Marine Environment Management Act of South Korea prescribes its jurisdiction based on the flag state of the violated vessel and location of the spills, UNCLOS prescribes coastal state’s jurisdiction based on the severity of pollution damage and compliance on procedures. Therefore, some supplements on related laws need to be made.

On the Structural Behaviour to Penetration of Striking Bow under Collision Incidents between Two Ships

This work addressed the evaluation of collision angle and indenter on the behaviour of target object. A series of collision scenarios based on the mentioned parameters were calculated using finite element method. In the analysis process, several striking ships of different sizes relative to the struck ship are deployed as the collision angles ranging from 0° to 180° are taken into consideration. The results relative to the angles show that the perpendicular collision or a collision angle of 90° produces the lowest level of the internal energy in the side collision category by comparison with oblique collisions in the range of collision angles from 30° to 150°. The internal energy is found to be satisfactory when it is compared with the extent of the damage on the outer shell, which is also matched with the predicted energy behaviour from energy formulae.

Comparing Structural Casualties of the Ro-Ro Vessel Using Straight and Oblique Collision Incidents on the Car Deck

Roll on-roll off (Ro-Ro) ship is the preferable vessel for public transportation and also as a medium to distribute several commodities. Its operations are a straightforward process but traffic management is quite delicate, especially for cross-route. Moreover, maritime incidents sometimes occur, causing significant casualties and in the case of the Ro-Ro, collision with other ship is a possible threat with the ability to trigger immense damages. This research, therefore, was conducted to assess the structural casualties of a Ro-Ro vessel under collision. This was modelled with respect to a ship involved in a certain incident in Indonesia in the latest decade, and the designed collision problems were calculated using the finite element approach. The collision angle was selected as the main input parameter with the straight collision of angle 90° and oblique collision with different angles applied to the scenario. The results found the collision energy due to structural destruction to have distinct pattern and peak value under oblique cases with lower values observed for straight collision for all scenarios. It is, however, recommended that energy should be taken as an initial parameter in further investigation of structural damage and response contour.

Medical assessment of potential concussion in elite football: video analysis of the 2016 UEFA European championship

ObjectiveThe objective is to determine if suspected concussions in elite football are medically assessed according to the International Conferences on Concussion in Sport consensus statement recommendations.SettingMen’s Union of European Football...

Collision Incidents of Single Tetrahexahedral Platinum Nanocrystals Recorded by a Carbon Nanoelectrode

AbstractRecently, collision mode has been adopted to study the electrochemical or photoelectrochemical behavior of single particles touching and/or attaching on a biased ultramicroelectrode (UME). However, to correlate the reaction activity to the nanocrystal structure still remains challenging because of: (1) the uncontrolled structure and size of the single nanoparticle; (2) the uncertainty of one particle in each collision incident since the size of UME is much larger than that of the single nanoparticle. To these problems, we synthesized well‐defined convex tetrahexahedral platinum nanocrystals (THH Pt NC) with an average size of 30 nm and fabricated a carbon nanoelectrode through pyrolysis of butane. The current fluctuation caused by oxygen reduction reaction (ORR) during the single collision incident of THH Pt NC was detected by the carbon nanoelectrode. It is reasonable to use nanocrystals with well‐defined morphology and size in the collision experiments. However, the adoption of nanoelectrode will decrease the collision frequency and shorten the standing time of nanocrystals on the electrode surface. How to figure out the kinetics from the current fluctuations in the single collision incident still remains challenging.

Performance and sensitivity analysis of UHPFRC-strengthened bridge columns subjected to vehicle collisions

Bridge columns made of normal concrete are evidenced to be susceptible to vehicle collisions. Particularly in the United States, vehicle collision has become one of the primary causes of bridge failures. This is largely due to the low crashworthiness of a conventional reinforced concrete (RC) column. Ultra-high-performance fiber-reinforced concrete (UHPFRC) as one of advanced concrete materials has been experimentally demonstrated to possess excellent strength, durability, impact resistance and energy-absorbing capacity. Accordingly, one type of UHPFRC-strengthened columns was proposed in this study as an alternative to RC columns that may be at risk for vehicle collision incidents. High-resolution finite element (FE) models were developed to investigate the performance of UHPFRC-strengthened columns subjected to vehicle collisions. In the high-resolution FE model, a three-span simply-supported girder bridge (including girder, pier column, column cap, bearing, etc.) was adopted and modelled. Material models regarding normal concrete and UHPFRC as well as the vehicle model were carefully calibrated by experimental data. The influence of initial gravity loads on impact responses was found to be pronounced, and a damping-based method was proposed to efficiently exert permanent loads on pier columns prior to a collision. Three different simplified models, as published in current studies, were investigated to replace the whole bridge model. Two single-column models with different boundaries were shown to have low accuracy. The pier-bent model considering the superstructure gravity was demonstrated as capable of predicting collision-induced responses that are in good agreement with the high-resolution FE model. The impact resistances of both RC and UHPFRC-strengthened columns were extensively investigated using the appropriate simplified model. The crashworthiness of UHPFRC-strengthened column was found to be considerably superior to that of RC column. An extensive parametric study was performed using response surface methodology to explore the influences of reinforcement ratios, thickness of UHPFRC jacket, UHPFRC strength and initial impact speed. The impact-resistant performance is mostly sensitive to changes in the thickness of UHPFRC jacket when the impact speed is not very high. On the contrary, the residual capacity of the bridge column is hardly increased by thickening UHPFRC jacket. In addition, the developed response surface models provided easy estimation of impact-induced responses of an UHPFRC-strengthened column, which have potential use as the surrogates of time-consuming FE simulations to efficiently examine the reliability and optimization of bridge columns under impact loadings.

Investigation of impact phenomena on the marine structures: Part II - Internal energy of the steel structure applied by selected materials in the ship-ship collision incidents

Phenomena of impact loads on the marine structures has attracted attention to be predicted regarding its influences to structural damage. This part demands sustainable analysis and observation as tendency may vary from one to others since impact involves various scenario models and the structure itself experiences continuous development. Investigation of the damage extent can be conducted by observation on the energy behaviour during two entities involve in a contact. This study aimed to perform numerical investigation to predict structural damage by assessing absorbed strain energy represented by the internal energy during a series of ship collisions. The collision target in ship-ship interactions were determined on the single and double hulls part of a passenger ship. Tendency of the internal energy by the steel structures was summarized, and verification was presented by several crashworthiness criteria. It was found that steel structures applied by the material grades A and B produced different tendencies compared to the material grades D and E. Effect of the structural arrangement to structural responses in terms of strain and stress indicated that the single hull presented contour expansion mainly on the longitudinal directions.

Coming back into the loop: Drivers’ perceptual-motor performance in critical events after automated driving

This driving simulator study, conducted as part of the EU AdaptIVe project, investigated drivers’ performance in critical traffic events, during the resumption of control from an automated driving system. Prior to the critical events, using a between-participant design, 75 drivers were exposed to various screen manipulations that varied the amount of available visual information from the road environment and automation state, which aimed to take them progressively further ‘out-of-the-loop’ (OoTL). The current paper presents an analysis of the timing, type, and rate of drivers’ collision avoidance response, also investigating how these were influenced by the criticality of the unfolding situation. Results showed that the amount of visual information available to drivers during automation impacted on how quickly they resumed manual control, with less information associated with slower take-over times, however, this did not influence the timing of when drivers began a collision avoidance manoeuvre. Instead, the observed behaviour is in line with recent accounts emphasising the role of scenario kinematics in the timing of driver avoidance response. When considering collision incidents in particular, avoidance manoeuvres were initiated when the situation criticality exceeded an Inverse Time To Collision value of ≈0.3s−1. Our results suggest that take-over time and timing and quality of avoidance response appear to be largely independent, and while long take-over time did not predict collision outcome, kinematically late initiation of avoidance did. Hence, system design should focus on achieving kinematically early avoidance initiation, rather than short take-over times.

Assessment of road-rail crossing collision derailments on curved tracks

Collision incidents involving trains and road vehicles at road-rail crossings are common occurrences, which are fatal and incur significant economic and societal costs. The existing studies of train collision derailments mainly focus on the rail vehicles running on straight tracks, while the derailments induced by train-truck collision at a road-rail crossing in curved tracks are rarely investigated, although such crossings are more common. This paper presents a study of the derailment assessment of passenger trains due to the collision with heavy road trucks stuck across the curved road-rail crossing by means of train-track dynamics simulations. For this purpose, a nonlinear three-dimensional model of a passenger train impacting a road truck stuck on curved tracks is developed based on the multi-body dynamics theory. Sensitivity of key design parameters such as the curve radius, the collision point at the curved track section, and the impact direction between the train and the truck, and their effects on the derailment behaviour of colliding trains are reported. The results show that the derailment potential is higher at smaller radius track and at the circular curves.

Actual and perceived collision risk for bird strikes at Namibian airports

At Namibia’s two major airports, Hosea Kutako International and Eros (domestic), 117 bird strike collision incidents were recorded between 2006 and 2010. A risk assessment, which included a proposed risk weighting methodology, was conducted at Hosea Kutako and Eros airports, which estimated the probability of an accident/collision as well as the consequence of such a collision. The assessment included surveys of bird occurrence frequencies as well as pilot interviews. The results of the risk assessments were compared with actual bird strike incidences for each species, frequency of occurrence of birds and pilot perceptions of species risk, in order to find whether risk assessment and pilot perception are reliable measures of potential bird strike incidence. White-backed Vulture Gyps africanus and Helmeted Guineafowl Numida meleagris were the highest risk species at both airports. They were also, after Crowned Lapwing Vanellus coronatus, the species most often observed by pilots. Bird strike records showed that Crowned Lapwing and Helmeted Guineafowl were also the most frequently struck birds at both airports. The study illustrates how combining risk assessment, pilot perception and bird strike history can benefit bird strike minimisation plans at airports through the rapid identification of priority bird species.

Response-Spectrum Analysis for Barge Impacts on Bridge Structures

AbstractBridge structures that span navigable waterways are inherently at risk for barge collision incidents and therefore must be designed for impact loading. Current U.S. barge impact analysis procedures consist primarily of static load analysis methods that do not explicitly account for dynamic effects in barge–bridge collisions, and thus are not ideally suited to designing bridge structures to resist barge impacts. Therefore, the development of dynamic-analysis methods for estimating the responses of bridge structures to barge collisions is warranted. Dynamic-analysis procedures that use numerical time-integration techniques are capable of capturing pertinent dynamic effects but often yield voluminous amounts of time-varying results that must be post processed for use in design. In contrast, response-spectrum analysis (RSA) procedures are capable of directly producing maximum response parameters that are most pertinent to structural design. In this paper, an RSA procedure is proposed for use in barge ...

A Wearable-Based and Markerless Human-Manipulator Interface with Feedback Mechanism and Kalman Filters

The objective of this paper is to develop a novel human-manipulator interface which incorporates wearable-based and markerless tracking to interact with the continuous movements of a human operator's hand. Unlike traditional approaches, which usually include contacting devices or physical markers to track the human-limb movements, this interface enables registration of natural movement through a wireless wearable watch and a leap motion sensor. Due to sensor error and tracking failure, the measurements are not made with sufficient accuracy. Two Kalman filters are employed to compensate the noisy and incomplete measurements in real time. Furthermore, due to perceptive limitations and abnormal state signals, the operator is unable to achieve high precision and efficiency in robot manipulation; an adaptive multispace transformation method (AMT) is therefore introduced, which serves as a secondary treatment. In addition, in order to allow two-way human-robot interaction, the proposed method provides a vibration feedback mechanism triggered by the wearable watch to call the operator's attention to robot collision incidents or moments where the operator's hand is in a transboundary state. This improves teleoperation.

Simplified analytical method to evaluate tanker side panels during minor collision incidents

The paper presents a simplified analytical method to examine the energy absorbing mechanisms of small-scale stiffened plate specimens, quasi-statically punched at the mid-span by a rigid indenter with a knife or a flat edge shape. To validate this method, experiments and numerical simulations are conducted on specimens scaled from a tanker side panel limited by one span between the web frames and the stringers. Therefore, the paper provides practical information to estimate the extent of structural damage within ship side panels during collision accidents. The experimentally obtained force–displacement responses and shapes of the deformation show good agreement with the simulations performed by the explicit LS-DYNA finite element solver. The numerical results manage to describe the process of initiation and propagation of the material fracture in the side panel specimens and provide detailed information of the energy dissipated by each structural component and its contribution to total energy during the entire deformation process. The analytical method derives expressions to estimate the relation between the plastic deformation and the energy dissipation of the stiffened plates. Both the plate and the stiffener elements dissipate the energy through rotation of the plastic hinges at the applied load and the support and the membrane tension over the plastically deformed region between the loading and the supports. The proposed simplified expressions give a good agreement with the experimental and numerical results.

Seeing is Believing

Big data sets can be cumbersome and difficult to understand. User-centered and interactive graphical displays help communicate messages from large and complex data as well as provide a new method to identify data trends outside of tabular or statistical analysis. Human factors researchers can utilize data visuals to not only develop but also answer questions that previously proved difficult through visual exploration. This approach is especially relevant to the field of surface transportation research where complex plots can incorporate both temporal and geospatial data in an easy-to-digest format. As a proof of concept, this paper demonstrates how bike-sharing and historical bicycle collision incidents can meaningfully merge to produce graphical displays that readily identify and communicate potential infrastructure problems for safety. Through the use of Bayesian modeling and geospatial mapping, our analysis identifies two primary trends worth further consideration and research to consider for cyclist safety in Chicago.

Abnormal Event Detection of Traffic Intersection Based on SAT Algorithm

SAT (Separating Axis Theorem) is an algorithm applied in two-dimensional games of collision detection in the convex polygon. This paper applied SAT algorithm into video monitoring at intersections to detect the vehicles collision incidents. Established separation axis to extracted vehicles and projected the target vehicles into separation axis. Through comparing the scalar value in separation axis to determine whether the target vehicles collision. It's proved that the method is effective by using Matlab software to the simulation test in this algorithm.

GISを用いた瀬戸内海の衝突海難発生傾向

Seto Inland Sea area contains the national park, marine traffic routes and fishing bank, where many fishing boats and various kinds of vessels are sailing. Especially, feeder vessels, which are involved in foreign-trade between Japan and other Asian countries, are making the traffic more and more complicated in the area. And those vessels are less than 10,000 gross tonnages and do not follow compulsory pilotage, and as the result, they have caused an increasing the number of collision incidents. n this paper, the authors analyze the ship collisions in Seto Inland Sea using Geographic Information System (GIS), and investigate the relationship between ship collisions and the near misses that have been reported from the Seto Inland Sea Pilots Association. For example, the authors create a hazard map with easy suggestions to ship operators for the purpose of contribution to safety of marine traffic.