Considerations Concerning Vehicle Collisions Through Simplified Calculations of the Impact Forces

1996 ◽  
Author(s):  
Helcio Onusic ◽  
José Augusto P. Campos ◽  
Paulo Sergio P. dos Santos
Keyword(s):  
Vehicle Collisions ◽  
Impact Forces ◽  
The Impact

scholarly journals The implications of vehicle collisions for the Endangered endemic Zanzibar red colobus Piliocolobus kirkii

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Harry Olgun ◽  
Mzee Khamis Mohammed ◽  
Abbas Juma Mzee ◽  
M. E. Landry Green ◽  
Tim R. B. Davenport ◽  
...  
Keyword(s):  
Road Ecology ◽  
Local Population ◽  
Red Colobus ◽  
Vehicle Collisions ◽  
The Road ◽  
Life History Data ◽  
Natural Predation ◽  
Historical Accounts ◽  
The Impact

Abstract Roads affect wildlife in a variety of negative ways. Road ecology studies have mostly concentrated on areas in the northern hemisphere despite the potentially greater impact of roads on biodiversity in tropical habitats. Here, we examine 4 years (January 2016–December 2019) of opportunistic observations of mammalian roadkill along a road intersecting Jozani-Chwaka Bay National Park, Unguja, Zanzibar. In particular, we assess the impact of collisions on the population of an endemic primate, the Endangered Zanzibar red colobus Piliocolobus kirkii. Primates accounted for the majority of roadkill in this dataset. Monthly rainfall was not associated with roadkill frequency for mammals generally, nor for the Zanzibar red colobus. No single age–sex class of colobus was found dead more often than expected given their occurrence in the local population. The overall effect of roadkill on colobus populations in habitats fragmented by roads is unknown given the lack of accurate, long-term life history data for this species. Our findings suggest that mortality from collisions with vehicles in some groups of colobus is within the range of mortality rates other primates experience under natural predation. Unlike natural predators, however, vehicles do not kill selectively, so their impact on populations may differ. Although a comparison with historical accounts suggests that the installation of speedbumps along the road near the Park's entrance has led to a significant decrease in colobus roadkill, further actions to mitigate the impact of the road could bring substantial conservation benefits.

scholarly journals Driver Liability Assessment in Vehicle Collisions in Spain

2021 ◽  
Vol 18 (4) ◽  
pp. 1475
Author(s):  
Almudena Sanjurjo-de-No ◽  
Blanca Arenas-Ramírez ◽  
José Mira ◽  
Francisco Aparicio-Izquierdo
Keyword(s):  
Road Safety ◽  
Accurate Estimation ◽  
Main Hypothesis ◽  
Self Organizing Maps ◽  
Safety Measures ◽  
Vehicle Collisions ◽  
Promising Tool ◽  
Visual Clustering ◽  
Open Question ◽  
The Impact

An accurate estimation of exposure is essential for road collision rate estimation, which is key when evaluating the impact of road safety measures. The quasi-induced exposure method was developed to estimate relative exposure for different driver groups based on its main hypothesis: the not-at-fault drivers involved in two-vehicle collisions are taken as a random sample of driver populations. Liability assignment is thus crucial in this method to identify not-at-fault drivers, but often no liability labels are given in collision records, so unsupervised analysis tools are required. To date, most researchers consider only driver and speed offences in liability assignment, but an open question is if more information could be added. To this end, in this paper, the visual clustering technique of self-organizing maps (SOM) has been applied to better understand the multivariate structure in the data, to find out the most important variables for driver liability, analyzing their influence, and to identify relevant liability patterns. The results show that alcohol/drug use could be influential on liability and further analysis is required for disability and sudden illness. More information has been used, given that a larger proportion of the data was considered. SOM thus appears as a promising tool for liability assessment.

The Effects of Upstream Flexible Barrier on the Debris Flow Entrainment and Impact Dynamics on a Terminal Barrier

2021 ◽  
Author(s):  
Hervé Vicari ◽  
C.W.W. Ng ◽  
Steinar Nordal ◽  
Vikas Thakur ◽  
W.A. Roanga K. De Silva ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Impact Force ◽  
Dynamic Pressure ◽  
Pressure Coefficient ◽  
Flexible Barrier ◽  
Impact Forces ◽  
Flexible Barriers ◽  
The Impact ◽  
Bed Entrainment

The destructive nature of debris flows is mainly caused by flow bulking from entrainment of an erodible channel bed. To arrest these flows, multiple flexible barriers are commonly installed along the predicted flow path. Despite the importance of an erodible bed, its effects are generally ignored when designing barriers. In this study, three unique experiments were carried out in a 28 m-long flume to investigate the impact of a debris flow on both single and dual flexible barriers installed in a channel with a 6 m-long erodible soil bed. Initial debris volumes of 2.5 m<sup>3</sup> and 6 m<sup>3</sup> were modelled. For the test setting adopted, a small upstream flexible barrier before the erodible bed separates the flow into several surges via overflow. The smaller surges reduce bed entrainment by 70% and impact force on the terminal barrier by 94% compared to the case without an upstream flexible barrier. However, debris overflowing the deformed flexible upstream barrier induces a centrifugal force that results in a dynamic pressure coefficient that is up to 2.2 times higher than those recommended in guidelines. This suggests that although compact upstream flexible barriers can be effective for controlling bed entrainment, they should be carefully designed to withstand higher impact forces.

Resolving the Unique Invariant Slip-Direction in Rigid Three-Dimensional Multi-Point Impacts at Stick-Slip Transitions

2018 ◽  
Author(s):  
Abhishek Chatterjee ◽  
Alan Bowling
Keyword(s):  
Single Point ◽  
Three Dimensional ◽  
Impact Behavior ◽  
Slip Direction ◽  
Stick Slip ◽  
Impact Forces ◽  
Post Impact ◽  
Impact Problems ◽  
Slip Transition ◽  
The Impact

This work presents a new approach for resolving the unique invariant slip direction at Stick-Slip Transition during impact. The solution method presented in this work is applicable to both single-point and multi-point impact problems. The proposed method utilizes rigid body constraints to resolve the impact forces at all collision points in terms of a single independent impact forces parameter. This work also uses an energetic coefficient of restitution to terminate impact events, thereby yielding energetically consistent post-impact behavior.

scholarly journals Evolution of mantis shrimp telson armour and its role in ritualized fighting

2019 ◽  
Vol 16 (157) ◽  
pp. 20190203 ◽  
Author(s):  
Jennifer R. A. Taylor ◽  
Nina I. Scott ◽  
Greg W. Rouse
Keyword(s):  
Comparative Analysis ◽  
Impact Resistance ◽  
High Impact ◽  
Mantis Shrimp ◽  
Impact Forces ◽  
Drop Tests ◽  
Impact Parameters ◽  
Ritualized Combat ◽  
Stiff Spring ◽  
The Impact

Mantis shrimp possess both formidable weapons and impact-resistant armour that clash during ritualized combat. The telson is one of few biological structures known to withstand the repeated high impact forces of smashing mantis shrimp strikes, and it is hypothesized that this pairing of armour and weapon is associated with the evolution of telson sparring. We carried out a comparative analysis of telson impact mechanics across 15 mantis shrimp species to assess if the telsons of sparring species (i) are consistently specialized for impact-resistance, (ii) are more impact-resistant than those of non-sparring species, and (iii) have impact parameters that correlate with body size, and thereby useful for assessment. Our data from ball drop tests show that the telsons of all species function like a stiff spring that dissipates most of the impact energy, but none of the measured impact parameters are correlated with the occurrence of sparring behaviour. Impact parameters were correlated with body mass for only some species, suggesting that it is not broadly useful for size assessment during ritualized fighting. Contrary to expectation, sparring mantis shrimp do not appear to have coevolved telson armour that is more robust to impact than non-sparring species. Rather, telson structure is inherently impact-resistant.

scholarly journals Comparison of branded rugby headguards on their effectiveness in reducing impact on the head

2018 ◽  
Vol 4 (1) ◽  
pp. e000361 ◽  
Author(s):  
Erin R A Frizzell ◽  
Graham P Arnold ◽  
Weijie Wang ◽  
Rami J Abboud ◽  
Tim S Drew
Keyword(s):  
Impact Force ◽  
Linear Acceleration ◽  
Baseline Measurement ◽  
Peak Acceleration ◽  
Impact Forces ◽  
Impact Attenuation ◽  
The Mean ◽  
Force Reduction ◽  
The Right ◽  
The Impact

AimTo compare the available brands of rugby headguards and evaluate their impact attenuation properties at various locations on the cranium, with regard to concussion prevention.MethodsSeven different branded headguards were fitted onto a rigid headform and drop-tested in three different positions. An accelerometer measured the linear acceleration the headform experienced on impact with the ground. Each test involved dropping the headform from a height that generated 103.8 g on average when bare, which is the closest acceleration to the upper limit of the concussion threshold of 100 g. A mean peak acceleration for each drop position was calculated and compared with the bare baseline measurement.ResultsEach headguard demonstrated a significant decrease in the mean peak acceleration from the baseline value (all p≤0.01). Overall the Canterbury Ventilator was the most effective headguard, decreasing the impact force on average by 47%. The least effective was the XBlades Elite headguard, averaging a force reduction of 27%. In five of the seven headguards, the right side of the headwear was the most effective at reducing impact force.ConclusionOverall, the results indicate that it would be beneficial to wear a headguard during rugby in order to reduce the impact forces involved in head collisions. There was also a clear difference in performance between the tested brands, establishing the Canterbury headguard as the most effective. However, only one model of headguard from each brand was tested, so further research evaluating all other models should be considered.

scholarly journals STUDY ON IMPACT FORCES OF THE UNDERWATER CAVITY PROJECTILE

2016 ◽  
Vol 54 (6) ◽  
pp. 797
Author(s):  
Nguyen Thai Dung ◽  
Nguyen Duc Thuyen
Keyword(s):  
Drag Force ◽  
Impact Force ◽  
Center Of Mass ◽  
Forward Direction ◽  
Cavity Wall ◽  
Impact Point ◽  
Impact Forces ◽  
Underwater Projectile ◽  
The Impact ◽  
Cavity Effect

The motion of the underwater projectile with cavity effect including two motions: the projectile moves in the forward direction, center of mass of the projectile rotation around its nose makes tail of the projectile impacts on the cavity wall. According to, the impact forces occur, they include the drag force at its none, the impact force at impact point. The paper studies the forces occur on during motion of the underwater cavity projectile. Added, this paper considers the effect of the length and distributive projectile to the magnitude of impact force and the drag force of the underwater cavity projectile.

MP9-16 THE IMPACT OF SEAT BELTS AND AIRBAGS ON HIGH GRADE RENAL INJURIES AND NEPHRECTOMY RATES IN MOTOR VEHICLE COLLISIONS

2014 ◽  
Vol 191 (4S) ◽  
Author(s):  
Marc Bjurlin ◽  
Richard Fantus ◽  
Michele Mellett ◽  
Richard Fantus ◽  
Dana Villines
Keyword(s):  
Motor Vehicle ◽  
High Grade ◽  
Seat Belts ◽  
Motor Vehicle Collisions ◽  
Vehicle Collisions ◽  
The Impact ◽  
Renal Injuries

Predicting the Impact Response of a Nonlinear Single-Degree-of-Freedom Shock-Absorbing System From the Measured Step Response

1997 ◽  
Vol 119 (3) ◽  
pp. 221-227 ◽  
Author(s):  
S. N. Robinovitch ◽  
W. C. Hayes ◽  
T. A. McMahon
Keyword(s):  
High Energy ◽  
Degree Of Freedom ◽  
Step Response ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Impact Forces ◽  
Standard Linear Solid ◽  
Standard Linear ◽  
The Impact ◽  
Measured Response

We measured the step response of a surrogate human pelvis/impact pendulum system at force levels between 50 and 350 N. We then fit measured response curves with four different single-degree-of-freedom models, each possessing a single mass, and supports of the following types: standard linear solid, Voigt, Maxwell, and spring. We then compared model predictions of impact force during high-energy collisions (pendulum impact velocity ranging from 1.16 to 2.58 m/s) to force traces from actual impacts to the surrogate pelvis. We found that measured peak impact forces, which ranged from 1700 to 5600 N, were best predicted by the mass-spring, Maxwell, and standard linear solid models, each of which had average errors less than 3 percent. Reduced accuracy was observed for the commonly used Voigt model, which exhibited an average error of 10 percent. Considering that the surrogate pelvis system used in this study exhibited nonlinear stiffness and damping similar to that observed in simulated fall impact experiments with human volunteers, our results suggest that these simple models allow impact forces in potentially traumatic falls to be predicted to within reasonable accuracy from the measured response of the body in safe, simulated collisions.

Sign in / Sign up

Export Citation Format

Share Document