Non-Linear Damage Analysis in Accident Reconstruction

Woolley, Ronald L.

doi:10.4271/2001-01-0504

Cited by 30 publications

(6 citation statements)

References 37 publications

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“…The vehicle acceleration increased with speed until a plateau of approximately 300 to 350 m/s2 was reached. This plateau like behavior has previously been described by Campbell (1974) and by Wood et al (1993), and has been modeled in accident reconstruction with the force saturation model (Strother et al 1986) and the power-law model, Woolley (2001).…”

Section: Overlap and Speed Effectssupporting

confidence: 57%

Vehicle Acceleration and Compartment Intrusion for Far-Sided Occupants v. Near-Sided Occupants in Frontal Offset Collisions

Jewkes

2003

SAE Technical Paper Series

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Vehicle acceleration and compartment intrusion play major roles in occupant injury causation, in frontal offset collisions. The knowledge of injury causation may enable the injury risk to be directly assessed from accident conditions, once a relationship between accident conditions and vehicle response is known. To establish such a relationship, a simulation study was carried out, in which vehicle acceleration and local compartment intrusion were calculated for various crash speeds and overlap configurations. The simulation model was validated against crash-tests in terms of the local vehicle deformation, acceleration and local dash and toepan intrusion. It was found that average acceleration generally decreased with reduced overlap, while intrusion increased for narrower overlap and impact locations more closely to the dash and/or toepan. This general trend indicates the relatively high injury risk for nearside occupants and a low risk for far-side occupants. Farside, low-overlap (<50%) offset collisions at 45 or even 50 mph resulted in similar average acceleration and local intrusion levels as those seen in full overlap at 35 mph. However, crush reaching into the stiff firewall may cause vehicle peak accelerations to rise above expected levels in low overlap and high speed, especially in case the engine enhances firewall deformation. Furthermore, far-side intrusions may reach similar levels as nearside intrusions in offset collisions (>33% overlap), due to induced damage and the load distributing effect of the engine. Vehicle average acceleration and local intrusion levels may reach injurious levels for the far-side occupant in offset collisions. Vehicle crashworthiness improvements with a sole focus on nearside occupants may result in reduced protection of the far-side occupant.

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Section: Overlap and Speed Effectssupporting

confidence: 57%

Vehicle Acceleration and Compartment Intrusion for Far-Sided Occupants v. Near-Sided Occupants in Frontal Offset Collisions

Jewkes

2003

SAE Technical Paper Series

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“…This research, based on Campbell's [1] pioneering work, has evolved into analysis procedures such as CRASH [2] and its latterday variants, EDCRASH [3], etc. Other research has shown that generalized non-linear relations and geometric crush shape representations can reflect car crush behaviour for velocity changes up to and over 120 km/h [4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Motorcycle-to-car and scooter-to-car collisions: speed estimation from permanent deformation

Wood¹,

Glynn²,

Walsh³

2009

Proceedings of the Institution of Mechanical Engineers, Part D:

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This paper proposes from fundamental mechanics that the specific energy ( E/ M) absorption characteristics of motorcycles and scooters in frontal impacts are similar where the primary load path is through the front wheel and fork assembly. Examination of 43 barrier test results for 14 different model types of motorcycle and scooter over the impact speed range from 10km/h to 76km/h shows that the specific energy versus wheelbase shortening characteristics are similar and that a single specific collision energy ( E/ M) regression equation with its associated statistical distribution ( r2=0.845) can be used to represent the motorcycle and scooter populations in frontal impact for wheelbase shortening up to 0.45m where the front-fork and front-wheel assemblies remain intact, albeit deformed. Data from 31 staged tests where motorcycles or scooters impacted stationary cars at 90° are used to obtain the energy absorption characteristics of the sides of cars subject to frontal motorcycle or scooter impact. These two regressions are used to estimate collision energy Eca from the permanent deformation or penetration depth of the collision partners, which, when substituted into the standard impact energy loss equation with the appropriate collision partner masses, yields an estimation of collision speed Vccs. This procedure for calculating collision closing speed Vccs is validated against 13 staged tests (six 90° impacts against stationary cars and seven angled impacts at angles up to 45° from the normal, four of which were against moving cars) and shows that the predicted Vccs speeds bound the actual speeds with a standard deviation of 11.2km/h for collision closing speeds up to 122km/h.

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“…In [21], the genetic algorithm is used to compute the model parameter (spring stiffness). The work [22] uses power law model to model the crash and experimental observation is done to obtain the impact attenuator parameters. The work [23] uses simple model of mass-spring to simulate the crash and the spring stiffness is obtained from full-scale experimental data analysis.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Similar to the works [21][22][23], the mathematical model of the impact attenuator in this work is built using the first principle as a continuous-time model, i.e., it comprises of mass-spring with an additional damper model. However, different from [21][22][23], we convert the continuous-time model into the discrete-time model using Euler method and we show the exact discrete-time model which is later coded into MATLAB's routine to simulate the problem. Additionally, different from the related works, the properties of the impact attenuator (the spring stiffness) are updated every time step by using the stiffness-strain data generated using quasi-static analysis in ANSYS Mechanical APDL which includes the elastic-plastic behavior of the impact attenuator.…”

Section: Introductionmentioning

confidence: 99%

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Development of impact attenuator analysis tools in crash scenario using Euler method and finite element analysis

et al. 2022

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The problem considered in this work is the development of simulation method for simulating car crash which utilizes simple car—impact attenuator model developed in MATLAB. Usually, car crash simulation is done using full finite element simulation which could take hours or days depending on the model size. The purpose of proposed method is to achieve quick results on the car crash simulation. Past works which utilizes simple car—impact attenuator model to simulate car crash use continuous time model and the impact attenuator parameter is obtained from the experimental results. Different from the related works, this work uses discrete time model, and the impact attenuator parameter is obtained from finite element simulation. Therefore, the proposed simulation method is not only achieving quick simulation results but also minimizing the cost and time in obtaining the impact attenuator parameter. The proposed method is suitable for parametric study of impact attenuator.

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Non-Linear Damage Analysis in Accident Reconstruction

Cited by 30 publications

References 37 publications

Vehicle Acceleration and Compartment Intrusion for Far-Sided Occupants v. Near-Sided Occupants in Frontal Offset Collisions

Vehicle Acceleration and Compartment Intrusion for Far-Sided Occupants v. Near-Sided Occupants in Frontal Offset Collisions

Motorcycle-to-car and scooter-to-car collisions: speed estimation from permanent deformation

Development of impact attenuator analysis tools in crash scenario using Euler method and finite element analysis

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