Side Impact Scenarios Research Articles

Design Loads and Pier Responses for Oblique Side Barge Impacts on Bridges

For bridges susceptible to barge collision, design provisions are typically utilized in determining collision scenarios and impact loading. Provisions in the United States require that bridges be designed to withstand two distinct collision events: direct (head-on) and glancing (e.g., oblique side). Head-on impact scenarios are represented using empirically determined static loads, and perpendicular impact loads are applied with magnitudes assumed equal to 50% of head-on impact loads. Subsequent to the formation of these provisions, numerous studies have identified the need to account for dynamic phenomena when designing bridges to resist vessel collision loads. Further, design-oriented computational techniques have been developed to characterize representative vessel–bridge collision scenarios, quantify dynamic barge impact loads, and compute time-varying bridge responses. While previous studies focused on head-on barge–bridge collision, the current study characterizes oblique side barge impact loading and resulting bridge response. Parameters such as barge flotilla configuration, impact angle, and location of impact initiation are investigated across a range of bridge models, leading to the identification of design-relevant oblique side impact scenarios. An alternative to the 50% design approach for oblique side impact scenarios involving the corners of barge bows is then proposed for assessing overall stability. The proposed approach incorporates dynamic phenomena and maintains agreement relative to more detailed analyses.

Innovative Active Head Restraint System in a Car: Safety Assessment with Virtual Human Body Model

<div class="section abstract"><div class="htmlview paragraph">The aim of this study is to use numerical simulations for safety assessment of an innovative active head restraint system. This system was developed to protect the head and neck of an occupant in a car without a head airbag during a side impact. Its FE model is created and embedded it in a model of a small car with a side airbag. The dynamics of the head restraint activation are also taken into account. The virtual human body model Virthuman is used to represent occupants. The model is scaled for pre-selected human individuals to cover large numbers of occupants of different sizes. It extends conventional virtual evaluation of new safety designs via existing pre-defined mono-purpose side dummies and their FE models. The benefit of the head restraint system is evaluated in side impact scenarios inspired by the pole tests performed by EuroNCAP. Transversal impacts to a pole at 29 and 32 km/h are considered at 90° and 75° angles from driver and the opposite side. Also, the far side impact prescribed with an acceleration pulse according to EuroNCAP is considered. Various initial driver sizes in standard seated positions are tested. To extend the study beyond standard testing protocols, out-of-position of driver is also considered, leading to more than 100 simulations of impact scenarios in total. The effect of the innovative head restraint system is assessed from the point of view of driver injury risk.</div></div>

Top tether effectiveness during side impacts

ABSTRACTObjective: Few studies have looked at the effectiveness of the top tether during side impacts. In these studies, limited anthropomorphic test device (ATD) data were collected and/or few side impact scenarios were observed. The goal of this study was to further understand the effects of the top tether on ATD responses and child restraint system (CRS) kinematics during various side impact conditions.Methods: A series of high-speed near-side and far-side sled tests were performed using the FMVSS213 side impact sled buck and Q3s ATD. Tests were performed at both 10° and 30° impacts with respect to the pure lateral direction. Two child restraints, CRS A and CRS B, were attached to the bench using flexible lower anchors. Each test scenario was performed with the presence and absence of a top tether. Instrumentation recorded Q3s responses and CRS kinematics, and the identical test scenarios with and without a top tether attachment were compared.Results: For the far-side lateral (10°) and oblique (30°) impacts, top tether attachment increased resultant head accelerations by 8–38% and head injury criterion (HIC15) values by 20–140%. However, the top tether was effective in reducing lateral head excursion by 5–25%. For near-side impacts, the top tether resulted in less than 10% increases in both resultant head acceleration and HIC15 in the lateral impact direction. For near-side oblique impacts, the top tether increased HIC15 by 17.3% for CRS A and decreased it by 19.5% for CRS B. However, the injury values determined from both impact conditions were below current injury assessment reference values (IARVs). Additionally, the top tether proved beneficial in preventing forward and lateral CRS rotations.Conclusions: The results show that the effects of the top tether on Q3s responses were dependent on impact type, impact angle, and CRS. Tether attachments that increased head accelerations and HIC15 values were generally counterbalanced by a reduction in head excursion and CRS rotation compared to nontethered scenarios.

Pedestrian injury severity in the event of a collision with a truck: are energy absorbing adaptive deformable fronts suitable

It is well known that adaptive deformable fronts attached to trucks reduce pedestrian injury. However, the suitability of these frontal attachment devices from a holistic point of view, considering both primary and secondary impacts, is questioned in this paper. Using head-injury-criteria index, the effects of pedestrian gait and different closing speeds are considered for evaluation of numerous truck-pedestrian side and rear impact situations. Numerical simulations, considering coupled rigid and deformable-body dynamics, have been carried out in this paper to arrive at conclusions. For primary side impact scenario DEA frontal attachment provides a performance improvement specifically for 0% gait; however, the performance improvement is non-uniform for other gait cycles. For primary rear impact scenarios, it is observed that DEA is not a useful alternative at all. For secondary collision scenarios (involving both side and rear impacts) DEA is not at all an effective means for performance improvement.

Pedestrian injury severity in the event of a collision with a truck: are energy absorbing adaptive deformable fronts suitable

It is well known that adaptive deformable fronts attached to trucks reduce pedestrian injury. However, the suitability of these frontal attachment devices from a holistic point of view, considering both primary and secondary impacts, is questioned in this paper. Using head-injury-criteria index, the effects of pedestrian gait and different closing speeds are considered for evaluation of numerous truck-pedestrian side and rear impact situations. Numerical simulations, considering coupled rigid and deformable-body dynamics, have been carried out in this paper to arrive at conclusions. For primary side impact scenario DEA frontal attachment provides a performance improvement specifically for 0% gait; however, the performance improvement is non-uniform for other gait cycles. For primary rear impact scenarios, it is observed that DEA is not a useful alternative at all. For secondary collision scenarios (involving both side and rear impacts) DEA is not at all an effective means for performance improvement.

Rapid prediction of damage on a struck ship accounting for side impact scenario models

AbstractThe impact phenomenon is inseparable part of every physical things, from substantial particle until macrostructure namely ship. In ship collisions, short-period load is distributed during impact process from striking ship into struck ship. The kinetic energy that is used to move striking ship is absorbed by struck ship that makes its structure undergoes plastic deformation and failure. This paper presents study that focuses on predicting occurred damage on side hull of struck ship for various impact scenario models. These scenarios are calculated by finite element approach to obtain characteristic on damage, energy as well as load during and after impact processes. The results indicate that the damages on impact to longitudinal components such as main and car decks are smaller than impact to transverse structure components. The damage and deformation are widely distributed to almost side structures including inner structure. The width between outer and inner shells is very affecting the damage mode where the width below the two meters will make inner shell experience damage beyond plastic deformation. The contribution of structure components is proofed deliver significant effect to damage mode and material strengths clearly affect the results in energy and load characteristic.

Behavior Prediction of Ship Structure due to Side Impact Scenario by Dynamic-Nonlinear Finite Element Analysis

The development of safety has become issue especially for marine and ocean vessels. However, the limitless possibilities of various phenomenon on the sea, make the observation and prediction of ship structure are continuously needed. Side impact is one of those phenomenon. Due to the complexity of ship structure, this phenomenon occurs and produces high nonlinearities, which influence the extent and contour of structural behavior. Such interesting phenomenon was reviewed and studied in present paper using dynamic finite element analysis as the effect of the dependent characteristic of phenomenon to time. Several side scenario models were used to obtain different results in respect of impact location. The kinetic and total energies were presented together with the contours of stress and displacement at two sides of side constructions. Results indicated that the contribution of construction arrangement was significantly affected stress distribution in longitudinal direction of ship hull, while displacement contour from certain scenario produced high intensity on longitudinal member of side construction.

Numerical Simulation for the Collision Between Side Structure and Level Ice in Event of Side Impact Scenario

WITH THE OPENING OF THE NORTHERN SEA FOR INTERNATIONAL SHIPPING ROUTES, VARIOUS VESSELS PREFER TO USE THIS OPTION TO REACH EUROPE AS DISTANCE IS SIGNIFICANTLY REDUCED IF A SHIP IS SAILING THROUGH THIS ROUTE. IN THE SAME TIME, THE DEMAND TO ENSURE SHIP SAFETY RISES AS IMPACT PHENOMENON BETWEEN SHIP STRUCTURES AND ICE CAUSES NUMEROUS CASUALTIES. THIS WORK PRESENTED A NUME-RICAL STUDY WITH A CONCENTRATION ON CONTACT BETWEEN SHIP STRUCTURES AND LEVELS. THE DOUBLE SIDE SKIN OF A CHEMICAL TANKER WAS MODELLED WITH A SHELL ELEMENT WHILE A DEFORMABLE CHARACTERISTIC WAS IMPLEMENTED ON THE ICE AS AN INDENTER. SEVERAL TARGET AREAS ON THE SIDE STRUCTURE WERE SET AS IMPACT POINTS BASED ON ITS STIFFENER COMPONENT. DIFFERENT MODELS OF INDENTER WERE TAKEN INTO ACCOUNT IN ORDER TO OBSERVE STRUCTURAL RESPONSES AND INFLUENCES OF EXTERNAL PARAMETERS, NAMELY ICE TOPOLOGY, WHILE THE DESCRIBED LOCATION PARAMETERS WAS TAKEN AS THE SHIP’S INTERNAL PARAMETERS. IMPACT FORCE WAS PRESENTED WITH TOTAL ENERGY, AS WELL AS THE RATIO BETWEEN KINETIC AND INTERNAL ENERGY. THE DEFORMATION PATTERN WAS USED AS A VERIFICATION OF THE COLLISION PROCESS AND ITS SUBSEQUENT RESULTS. FINALLY, THE BEHAVIOR OF THE INNER WALLS SUBJECTED TO TYPE INDENTERS WAS OBSERVED AS THIS COMPONENT IS THE FINAL COMPONENT THAT MAINTAINS LIQUID CARGO AND RESISTS AN IMPACT LOAD.

A new bird model and the effect of bird geometry in impacts from various orientations

In this paper, a bird model with geometry similar to a real bird (Bufflehead Duck) is introduced and compared to traditional bird models and also to experimental data. A bird can impact a part of an airplane from its head, tail, bottom or wings. Any of these orientations can have a different effect on the response of an airplane part. Since all birds do not have the same body shapes and sizes, and, since, it is not always convenient to model a complex bird body, four substitute bird models are introduced. The models results are then compared in order to determine the best substitute bird which can properly model the pressure and force exerted by real birds when impacting from different orientations. It was concluded that the impact from bird bottom side is the most damaging scenario, while the tail side impact is the less dangerous one. It was also found that for the tail side impact scenario, a hemispherical-ended cylinder shows the best results, while for the bottom side impact scenario, an ellipsoid can be the best candidate for the bird substitute model.

Non-linear finite element analyses of automobiles and their elements in crashes

During the last decade, automobile manufacturers have used computer simulations and are developing computer technology widely and more effectively to improve the crashworthiness of vehicles. Car manufacturers analyse the crashworthiness of vehicle designs in various crash scenarios, by means of advanced vehicle models, using finite element methods. This considerably reduces the number of costly crash tests performed with the designed vehicles in test labs. In this study, the deformation mechanism of vehicles was analysed in full frontal, offset frontal and side impact scenarios. The analyses used an explicit analysis algorithm within the ‘ANSYS/LS-DYNA’ program, using data models for various vehicles. The simulation results were compared with actual crash test data of the corresponding vehicles. The comparisons indicate that the obtained results are reliable and the algorithm used in these analyses can be useful in crash simulations, thereby considerably reducing the number of crash tests required during the automobile design process.

Side impact protection: the use of 3-D reinforced composite panels

Abstract Improved side impact protection for occupants in road passenger vehicles is urgently required if the rate of fatalities due to this type of collision is to be curbed. The current wide use of side impact bars has undoubtedly reduced the number of occupant fatalities in many lateral collisions. However, this paper shows that side impact bars are only effective when the target vehicle is struck at 90° (direct lateral impact) and whereby the side structure intrusion into the passenger safety cell is almost vertical and to a greater extent controlled by the collapse mechanisms of the B-post and the sill which carry much of the impact loads. Furthermore, the paper shows the most frequent side impact scenario is the frontal diagonal lateral collision which accounts for 64% of the total side impact. In this type of accident, the side impact bars are ineffective and become lethal wedges. They fail at low loads through shearing of joints or of areas of high stress concentration and, thereafter bend inward into the passenger safety cell. In order to protect occupants under front diagonal lateral collision and indeed under all types of side impacts, the paper has suggested an alternative method - using 3-D NEFESYF reinforced composite panels.