Lateral Collision Research Articles

Design and simulation of innovative foam-filled Lattice Composite Bumper System for bridge protection in ship collisions

In this paper, an innovative Foam-filled Lattice Composite Bumper System (FLCBS) with fiber-reinforced polymer (FRP) skins and a foam-web core is proposed as protective structures for bridge piers against ship collision. FLCBS consists of FRP face sheets, FRP lattice webs and polyurethane (PU) foam cores, which can be manufactured at the same time by vacuum assisted resin infusion process (VARIP). FLCBS exhibits good energy-absorbing and highly designable properties. The design, performance evaluation, manufacture and installation of FLCBS for a real prestressed concrete continuous girder bridge were introduced. A detailed numerical model for performance evaluation was developed with the explicit finite element (FE) software package ANSYS/LS-DYNA. An experimental study of two foam-filled lattice composite panels under low-velocity impact was conducted to verify the numerical model for FLCBS. The corresponding FE models of the composite panels generally showed good agreement, compared to the impact load history and mid-span deflection history of experimental results. Based on the validated numerical model, both head-on collision cases and lateral collision cases with and without FLCBS were investigated. Simulation of different impact angles, velocities and locations were carried out. Numerical results indicate the obvious advantages of FLCBS by comparing peak impact force and impact duration. Significantly decrement of the peak impact force and effectively prolonged impact process indicate the superior performance of FLCBS. The modular fabrication and replacement, easy and time-efficient installation and highly designable structure make FLCBS very attractive as bridge protection in ship collisions.

Frequency and characteristics of traumatic brain injury in restrained drivers involved in road traffic accidents.

While seatbelt is an important device protecting drivers from traumatic brain injury (TBI), it has rarely been reported how often and in what circumstances restrained drivers sustain TBI after road traffic accident (RTA). Whole-body computed tomography (WBCT) for blunt trauma patients may provide a unique opportunity to investigate the frequency and characteristics of TBI sustained by restrained drivers. A single-center, retrospective observational study was conducted using prospectively acquired data. Between January 2013 and December 2017, 409 restrained drivers (284 men/125 women, mean age of 45.0 ± 19.1years) whose vehicle had been severely damaged in RTAs underwent WBCT for evaluation of injuries. Multivariate regression analysis was performed to identify variables predictive of TBI. Influence of collision patterns (frontal, lateral or rollover) on the frequency and severity of TBI was evaluated. Relationship between collision patterns and CT findings was also reviewed. Thirty-one restrained drivers (7.6%) sustained TBI after RTA. The distribution of Glasgow Coma Scale (GCS) scores among the 31 drivers was 15 in 9, 13-14 in 9, 9-12 in 4, and ≤ 8 in 9, indicating that the majority of TBIs were classifiable as mild. The frequency of TBI in alert and oriented drivers, i.e., those with a GCS score of 15, was 2.9%. Multivariate regression analysis showed that both altered mental status (OR, 4.933; 95% CI, 1.135-21.431) and loss of consciousness (OR, 6.492; 95% CI, 1.669-25.249) were associated with TBI. The frequency of TBI tended to be higher in drivers with rollover collision than those with frontal collision (6 vs. 13%, p = 0.07). Interhemispheric acute subdural hematoma and subcortical petechial hemorrhage seemed to be characteristic CT findings in drivers with frontal and lateral collision, respectively. The key finding of this study, i.e., that (1) TBI was observed in 7.6% of restrained drivers with severe vehicular damage, may provide useful information to neurosurgeons who take care of RTA victims. The majority of the TBIs were mild without need for neurosurgical intervention. While association may exist between type of collision and type of brain injury, further studies with prospective design are warranted.

NANOCOMPOSITOS DE SILICE PARA FACIA: CARACTERIZACIÓN QUÍMICA,MECÁNICA Y SIMULACIÓN DE IMPACTO

Compound materials obtained by polyester resin reinforced with silica nanoparticles (RP/SiO2) were characterized by different mechanical essays. Test tubes were obtained under ASTM norms with SiO2 concentrations around 0.5 to 5% of weight. Compression tests indicated that silica nanoparticles lead to formation of ductile materials with respect to the polymer resin; compression deformation percentages (%e) were determined around 45-52 %; also, while the material resistance reached 90MPa. These materials showed a 38-67% increase in the bending module, and an increase of 16 to 34% in the absorption of impact energy. After mechanical characterization, was carried out a simulation of the mechanical behavior of bumper fascia made with the RP/SiO2-A using finite element software. Frontal and lateral collision indicated a maximum stress around 21.5 MPa and 28.36 MPa respectively, these results suggested that the auto-part will only show plastic deformation in some areas; due to the elastic limit for RP/SiO2 is 26 MPa and its maximum resistance at 89.8 MPa

Lateral Collision Avoidance Robust Control of Electric Vehicles Combining a Lane-Changing Model Based on Vehicle Edge Turning Trajectory and a Vehicle Semi-Uncertainty Dynamic Model

This paper presents a new control scheme for lateral collision avoidance (CA) systems to improve the safety of four-in-wheel-motor-driven electric vehicles (FIWMD-EVs). There are two major contributions in the design of lateral CA systems. The first contribution is a new lane-changing model based on vehicle edge turning trajectory (VETT) to make vehicle adapt to different driving roads and conform to drivers’ characteristic, in addition to ensure vehicle steering safety. The second contribution is vehicle semi-uncertainty dynamic model (SUDM), which is SISO model. The problem of stability performance without the information on sideslip angle is solved by the proposed SUDM. Based on the proposed VETT and SUDM, the lateral CA system can be designed with H∞ robust controller to restrain the effect of uncertainties resulting from parameter perturbation and lateral wind disturbance. Single and mixed driving cycles simulation experiments are carried out with CarSim to demonstrate the effectiveness in control scheme, simplicity in structure for lateral CA system based on the proposed VETT and SUDM.

Vehicle performance evaluation in side impact (MDB) using ES-II dummy

Side impact collision is one of the leading causes of death. Protection of people during lateral collision is challenging because of relatively small space available to restraint occupant compared to front. Hence, it is imperative to protect the occupants in side collision. It is a function of vehicle type and restraints for side protection. This paper focuses on evaluation of injury parameters of the ES II dummy during the lateral collision of different vehicles with different spaces, sections and materials. Thus the comparison will enable us to understand the sensitivity of space, B-pillar section and material which affects the injury parameters. This study will help automotive engineers to design side impact crashworthy vehicles.

Efficacy of seat-mounted thoracic side airbags in the German vehicle fleet

ABSTRACTObjective: Thoracic side airbags (tSABs) deploy within close proximity to the occupant. Their primary purpose is to provide a protective cushion between the occupant and the intruding door. To date, various field studies investigating their injury mitigation has been limited and contradicting. The research develops efficacy estimations associated for seat-mounted tSABs in their ability to mitigate injury risk from the German collision environment.Methods: A matched cohort study using German In-Depth Accident Study (GIDAS) data was implemented and aims to investigate the efficacy of seat-mounted tSAB units in preventing thoracic injury. Inclusion in the study required a nearside occupant involved in a lateral collision where the target vehicle exhibited a design year succeeding 1990. Collisions whereby a tSAB deployed were matched on a 1:n basis to collisions of similar severity where no airbag was available in the target vehicle. The outcome of interest was an incurred bodily or thoracic regional injury. Through conditional logistic regression, an estimated efficacy value for the deployed tSAB was determined.Results: A total of 255 collisions with the deployed tSAB matched with 414 collisions where no tSAB was present. For the given sample, results indicated that the deployed tSAB was not able to provide an unequivocal benefit to the occupant thoracic region, because individuals exposed to the deployed tSAB were at equal risk of injury (Thorax Maximum Abbreviated Injury Scale (Tho.MAIS)2+ odds ratio [OR] = 1.04, 95% confidence interval [CI], 0.41–2.62; Tho.MAIS3+ OR = 1.15, 95% CI, 0.41–3.18). When attempting to isolate an effect for skeletal injuries, a similar result was obtained. Yet, when the tSAB was coupled with a head curtain airbag, a protective effect became apparent, most noticeable for head/face/neck (HFN) injuries (OR = 0.59, 95% CI, 0.21–1.65).Conclusion: The reduction in occupant HFN injury risk associated with the coupled tSAB and curtain airbag may be attributable to its ability to provide coverage over previous mechanisms of injury. Yet, the sole presence of the tSAB showed no ability to provide additional benefit for the occupant's thoracic region. Future work should identify mechanisms of injury in tSAB cases and attempt to quantify improvements in the vehicle's ability to resist intrusion.

Fluid-induced transition from banded kyanite- to bimineralic eclogite and implications for the evolution of cratons

Heterogeneous, modally banded kyanite-bearing and bimineralic eclogites from the lithospheric mantle, collected at the Roberts Victor Diamond mine (South Africa), show a reaction texture in which kyanite is consumed. Geothermobarometric calculations using measured mineral compositions in Perple_X allowed the construction of a P-T path showing a steep, cool prograde metamorphic gradient of 2°C/km to reach peak conditions of 5.8GPa and 890°C for the kyanite eclogite. The kyanite-out reaction formed bimineralic eclogite and is probably an integral part of the mineralogical evolution of most archetypal bimineralic eclogites at Roberts Victor and potentially elsewhere. The kyanite-out reaction occured at close to peak pressure (5.3GPa) and was associated with a rise in temperature to 1380°C. Mass balance calculations show that upon breakdown, the kyanite component is fully accommodated in garnet and omphacite via a reaction system with low water fugacity that required restricted fluid influx from metasomatic sources. The δ18O values of garnets are consistently higher than normal mantle values. Each sample has its characteristic trend of δ18O variance between garnets in the kyanite-bearing sections and those in the bimineralic parts covering a range between 5.1‰ and 6.8‰. No systematic change in O-isotope signature exists across the sample population. Differences in garnet trace element signatures between differing lithologies in the eclogites are significant. Grossular-rich garnets coexisting with kyanite have strong positive Eu-anomalies and low Gd/Yb ratios, while more pyrope-rich garnets in the bimineralic sections have lost their positive Eu-anomaly, have higher Gd/Yb ratios and generally higher heavy rare earth element contents. Garnets in the original kyanite-bearing portions thus reflect the provenance of the rocks as metamorphosed gabbros/troctolites. The kyanite-out reaction was most likely triggered by a heating event in the subcratonic lithosphere. As kyanite contains around 100ppm of H2O it is suggested that the kyanite-out reaction, once initiated by heating and restricted metasomatic influx, was promoted by the release of water contained in the kyanite. The steep (high-P low-T) prograde P-T path defining rapid compression at low heating rates is atypical for subduction transport of eclogites into the lithospheric mantle. Such a trajectory is best explained in a model where strong lateral compression forces eclogites downward to higher pressures, supporting models of cratonic lithosphere formation by lateral collision and compression.

A crossover in anisotropic nanomechanochemistry of van der Waals crystals

In nanoscale mechanochemistry, mechanical forces selectively break covalent bonds to essentially control chemical reactions. An archetype is anisotropic detonation of layered energetic molecular crystals bonded by van der Waals (vdW) interactions. Here, quantum molecular dynamics simulations reveal a crossover of anisotropic nanomechanochemistry of vdW crystal. Within 10−13 s from the passage of shock front, lateral collision produces NO2 via twisting and bending of nitro-groups and the resulting inverse Jahn-Teller effect, which is mediated by strong intra-layer hydrogen bonds. Subsequently, as we transition from heterogeneous to homogeneous mechanochemical regimes around 10−12 s, shock normal to multilayers becomes more reactive, producing H2O assisted by inter-layer N-N bond formation. These time-resolved results provide much needed atomistic understanding of nanomechanochemistry that underlies a wider range of technologies.

Development of new deformable barriers for testing vehicle performance in different crash configurations

There are currently different deformable barriers that are used in crash testing, both lateral and frontal, in order to determine the level of protection of the vehicles and of injury to occupants, hereinafter referred to as crashworthiness. The definition and characteristics of these barriers, usually made from aluminium honeycomb, have evolved over time with the aim of improving the stiffness and capacity of absorbing the forces of a frontal impact of a vehicle type, and its compatibility with other vehicles in a real crash situation. In Europe, barriers defined by UN-ECE 94 (frontal collision) and UN-ECE 95 (lateral collision) regulations are currently used, although later developments such as the Advanced European Mobile Deformable Barrier (AE-MDB) will better represent the stiffness of the European-type vehicle. In the USA, the MDB developed by National Highway Traffic Safety Administration (NHTSA) is used in tests prescribed by the FMVSS 214D and FMVSS 301 standards, as well as other barriers such as that developed by the Insurance Institute for Highway Safety, whose dimensions, stiffness and mass are more similar to the features of the front structure of American suburban vehicles and pickups.These deformable barriers are useful for showing the deformation, deceleration levels, energy absorbed and for determining crashworthiness in different crash test configurations for which they were designed. However, they are not valid for other configurations, such as collisions involving heavy vehicles in which the total energy in play is very high, or when the crash affects different parts of the vehicle or at different angles of impact.This article describes the methodology followed to define the dimensions, stiffness and energy-absorbing capacity of the elements included in the design of new deformable barriers, which have to be capable of reproducing the vehicle behaviour depending on crash configurations and the size of the area of the vehicle affected by the collision. To do so, the available crash test data on certain types of vehicle were first collected. For each test, a series of characteristic parameters indicative of the severity of the collision were obtained. Then, a representative vehicle type was defined which corresponds to the average values of these parameters. Also, the design of the deformable barrier was addressed, and finite-elements models were made using solid elements with explicit formulation. The results of the barrier simulation were compared with the characteristic parameters of the representative vehicle type. In order to achieve an equivalence of the performance required, modifications to the design of the barrier were then made.This methodology is being applied to the design of new frontal barriers, which will be useful for assessing the crashworthiness of vehicles in types of collision which are different from those contemplated in current regulations.

Optimization design of traffic flow under security based on cellular automata model

Cellular Automata is a discrete model studied in computability theory, mathematics, physics, complexity science, theoretical biology and microstructure modeling. This paper proposes a model to balance the flux and safety, to maximize the flux on each road whilst ensuring work well with safety based on the Cellular Automata. In order to analyze the flow of traffic, the traffic of three-lane freeway and four-lane freeway are simulated based on the cellular automata model with the factors of velocity and density in the first step. For safety, a rear-end collision model and overtaking lateral collision model were employed to analyze the relation among safety. Reaction time and distance are introduced in the model, and different vehicles are considered. Safety-related factors are also chosen based on back propagation neural network. At last, this paper establishes a model to examine the performance of the traffic flow under the multi-lane freeway in light and heavy traffic. It simulates the situation in real life based on actual data. The optimal relation and optimal value has worked out between flux and safety through simulating the situation in real life based on actual data. To achieve a better model, further discussion, is made on how to adapt to different situations with the keep-left, the unrestricted, and the intelligent system controlled. The experimental result shows that the number of lanes is not an influential factor under any circumstances. The maximum speed limit plays a significant role in light traffic while it is of no importance in heavy traffic. However, the minimum speed limit plays a significant role in heavy traffic while it is of no importance in light traffic.

Tunnel collision during simultaneous anterior cruciate ligament and posterolateral corner reconstruction

To verify the safest angle to drill femoral tunnels in simultaneous anterior cruciate ligament (ACL) and posterolateral corner (PLC) reconstructions to minimize the risk of tunnel collision and to examine the relationship between lateral femoral condyle (LFC) width and tunnel collision occurrence. Ten fresh-frozen cadaveric knees were used. In each knee, anatomical single-bundle ACL femoral tunnels were arthroscopically drilled at 120 and 140 degrees of flexion, and tunnels for popliteus tendon (PLT) and fibular collateral ligament (FCL) were drilled at 20° axial/20° coronal angulations and 10° axial/30° coronal angulations. Three-dimensional computed tomography exams of the knees were performed. The presence of tunnel collision was evaluated, and the minimal distance between tunnels and the LFC width was measured. Risk of tunnel collision was significantly increased if FCL and PLT tunnels were drilled at 10° axial/30° coronal angulation (P < 0.05). Tunnel collision was noted in only one knee when FCL and PLT tunnels were drilled at 20° axial/20° coronal angulations. Knees with smaller LFC width had significantly higher risk for tunnel collision (P < 0.05). Drilling PLT and FCL femoral tunnels at 20° axial/20° coronal angulation is a safe positioning for simultaneous ACL and PLC reconstructions. However, in smaller knees, the risk for tunnel collision could be greater. Surgeons should consider the possibility of tunnel collision when performing simultaneous ACL and PLC anatomical reconstruction, especially in knees with a small LFC width where the risk for tunnel collision could be greater.

On the possible observational signatures of white dwarf dynamical interactions

We compute the possible observational signatures of white dwarf dynamical interactions in dense stellar environments. Specifically, we compute the emission of gravitational waves, and we compare it with the sensitivity curves of planned space-borne gravitational wave detectors. We also compute the light curves for those interactions in which a detonation occurs, and one of the stars is destroyed, as well as the corresponding neutrino luminosities. We find that for the three possible outcomes of these interactions - which are the formation of an eccentric binary system, a lateral collision in which several mass transfer episodes occur, and a direct one in which just a single mass transfer episode takes place - only those in which an eccentric binary are formed are likely to be detected by the planned gravitational wave mission eLISA, while more sensitive detectors would be able to detect the signals emitted in lateral collisions. On the other hand, the light curves (and the thermal neutrino emission) of these interactions are considerably different, producing both very powerful outbursts and low luminosity events. Finally, we also calculate the X-ray signature produced in the aftermath of those interactions for which a merger occurs. We find that the temporal evolution follows a power law with the same exponent found in the case of the mergers of two neutron stars, although the total energy released is smaller.

Lateral Collision with Side Airbag: A Literature Review

The paper presents a literature review of the efficacy of side passive safety in the event of lateral collision and the latest development of side airbag. According to the latest Global Status Report on Road Safety 2013, the total number of death every year due to road accident still maintained in a huge number of 1.24 million. Malaysia is one of the countries having highest estimated road traffic death rate of 25 per 100,000 populations. Moreover, 5% growth annually of fatalities rate forecasted. In general, lateral collision or side impact is the second most common vehicle crash type which takes almost 10,000 occupant deaths each year. Side airbags were introduced into vehicle firstly in 1995 in order to improve occupants injury. It is statically proven that combination of head with thorax side airbag is very effective in reducing occupants fatalities rate, however thorax only airbag is less significant. With the aid from Computer Aided Engineer (CAE) software, designer can further improve airbag design and optimize its performance in order to find the best combination of design parameter such as of area of air vent, Time-To-Fire (TTF), operating pressure of the inflator gas and many more, while design cycle time can be reduced significantly up to 40%. Nevertheless, people are afraid that side airbag deployment load may hurt children and small size female seated in Out-Of-Position (OOP). Researcher could resolve it by adopting the latest Computer Fluid Design (CFD) airbag simulation technique which have a better simulation result of OOP load, since CFD method provide more realistic airbag deployment simulations especially in the first few milliseconds which are significant in OOP test.

Surrogate safety measures as aid to driver assistance system design of the cognitive vehicle

The driver assistance system part of the cognitive vehicle design can prevent rear, lateral and other collisions by using a collision warning system that integrates intelligent technology and human factors. To be effective, such a system should be able to analyse driving states including driver distraction and driver intent, assess the likelihood of collisions by working with surrogate safety measures and issue warnings to the driver. This study presents a longitudinal and lateral collision warning model that allows the inclusion of key surrogate safety measures such as distance between vehicles in longitudinal vehicle-following mode or envelopes of vehicles in the lateral direction during lane migration/change/merge movements. The model can take into account values of driver distraction and driver intent variables obtained on-line or from off-line devices. The formulation is also applicable to time-to-crash surrogate safety measure. A pattern recognition method is used for the identification of pre-crash condition while minimising false alarms. The surrogate safety model is presented and illustrative examples are provided. The surrogate safety measure-based warning system is mainly intended for on-line use in actual driving conditions. In addition, it can be used in driving simulators or for off-line safety studies in association with microsimulators of traffic.

Traumatic Hemipelvectomy: Surgical and Medical-Legal Aspects

Background: Traffic accidents are major causes of disability and mortality due to the increasing number of vehicles, changes in lifestyle and high-risk behavior among the general population. Traumatic hemipelvectomy is a type of exceptional lesion representing 0.6% of all pelvic fractures, although lesions of the lower extremities are more usual than those of the upper extremities.Case presentation: The authors present an unusual case of traumatic left hemipelvectomy, and consider the medical-legal aspects resulting from an accident of a motorcycle driver, which involved a lateral collision between the subject’s motorcycle and a car.Conclusion: With traumatic hemipelvectomy in young subjects difficulties arise at any level and in all medical fields: clinically, surgical and medicolegal

Analysis for Lateral Collision Risk Assessment of RNAV Parallel Routes

Analysis for Lateral Collision Risk Assessment of RNAV Parallel Routes

Detonations in white dwarf dynamical interactions

In old, dense stellar systems collisions of white dwarfs are a rather frequent phenomenon. Here we present the results of a comprehensive set of Smoothed Particle Hydrodynamics simulations of close encounters of white dwarfs aimed to explore the outcome of the interaction and the nature of the final remnants for different initial conditions. Depending on the initial conditions and the white dwarf masses, three different outcomes are possible. Specifically, the outcome of the interaction can be either a direct or a lateral collision or the interaction can result in the formation of an eccentric binary system. In those cases in which a collision occurs, the infalling material is compressed and heated such that the physical conditions for a detonation may be reached during the most violent phases of the merger. While we find that detonations occur in a significant number of our simulations, in some of them the temperature increase in the shocked region rapidly lifts degeneracy, leading to the quenching of the burning. We thus characterize under which circumstances a detonation is likely to occur as a result of the impact of the disrupted star on the surface of the more massive white dwarf. Finally, we also study which interactions result in bound systems, and in which ones the more massive white dwarf is also disrupted as a consequence of the dynamical interaction. The sizable number of simulations performed in this work allows to find how the outcome of the interaction depends on the distance at closest approach, and on the masses of the colliding white dwarfs, and which is the chemical pattern of the nuclearly processed material. Finally, we also discuss the influence of the masses and core chemical compositions of the interacting white dwarfs and the different kinds of impact in the properties of the remnants.

Pilot study on constructing a real-world, in-depth database of occupant injury and vehicle damage after a domestic motor vehicle crash accident

This study develops a method to construct a real-world, in-depth database of occupant injury and vehicle damage after a domestic motor vehicle crash accident using examples of real motor vehicle crash accidents. Among the patients who visited the emergency rooms of three domestic hospitals due to motor vehicle crash accidents from January 2011 to June 2011, we collected data from patients whose ISSs (Injury Severity Scores) were over 16. We also surveyed the cause of the accident, information on the vehicle damage and the injury severity of the patient. Damage of the vehicle was presented using the CDC (Collision Deformation Classification) code by evaluating images of the damaged vehicle. In addition, the patient injury severity was evaluated using a trauma score. The number of subjects from 61 cases of motor vehicle crash accidents was 65, with an average age of 44.7±16.8. Of the 65 subjects, 54 (83.1%) were males, 49 (75.4%) were drivers, 29 (44.6%) were patients who did not fasten their seat belts and 20 (30.8%) were cases in which the airbags were deployed during the accident. The average maximum AIS (Abbreviated Injury Scale), ISS and RTS (Revised Trauma Score) were 3.78, 30.5 and 6.1, respectively. In the analysis of the CDC code, the average ISS was the highest (50.4) with rollover cases, and 7 subjects died, 4 involved in rollover accidents, 2 in fontal collisions and 1 in a lateral collision. To analyze occupant injury and vehicle damage after a domestic motor vehicle crash accident, it is necessary to construct a real-world, in-depth database that includes all information about the vehicle and the severity of the patient's injury. Language: en

Tectónica de las sierras penibéticas de Abdalajís y de Huma (provincia de Málaga, España). Su relación con el contacto con la Zona Interna

The Sierra de Abdalajis-Huma sector is part of the Penibetic and its structure mainly corresponds to dextral strike-slip faults of approximate N70oE direction. These faults are vertical or strongly dipping, with predominantly northward reverse component. There are also large anticlinal and synclinal folds. From the study of minor structures, a main compression of WNW-ESE direction that was progressively rotated to a NNW-SSE direction can be deduced. Folds limbs are commonly vertical, especially near the contact with the Internal Zone, which in this sector is a major vertical dextral fault. The structure of the area is related to the lateral oblique collision of the Internal Zone, then moving to the west. The movement between the two domains caused a relative eastward displacement of the Penibetic situated to the north of the Internal Zone. However the absolute displacement of both domains was to the west, although the northern part of the Penibetic did to a lesser degree.

Collision and dynamic frictional properties of boron nitride nanotubes

Collision and dynamic frictional properties of boron nitride nanotubes (BNNTs) are of importance to their structural applications related to impact protection. In this paper, we present an experimental study of the lateral collision between moving atomic force microscopy probe tips and individual standstill BNNTs. Our results reveal that increasing the impact velocity results in a more prominent increase of the collision force at low velocity levels. This observation is ascribed to the opposite influences of the impact velocity on the dynamic frictional force and the contact angle on the tip-tube collision contact.