Optimization of Vehicle Deceleration to Reduce Occupant Injury Risks in Frontal Impact

Mizuno, Koji; Itakura, Takuya; Hirabayashi, Satoko; Tanaka, Eiichi; Ito, Daisuke

doi:10.1080/15389588.2013.792408

Cited by 12 publications

(6 citation statements)

References 8 publications

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“…However, due to inertial forces of the head and upper extremities and their effects on chest injury measures, the shape of the optimized crash pulse when the chest acceleration was used as objective function was different from that when the chest deflection was used, especially in the final phase. This tendency was similar to results obtained by the Hybrid III dummy model simulation with the steepest descent method by Mizuno et al (2014).…”

Section: Discussionsupporting

confidence: 91%

“…3.0; Figure A4b), and the effectiveness of this optimized crash pulse was validated. The injury measures were compared to those determined from the steepest descent method, which was obtained in the previous study by Mizuno et al (2014). Figure 2 shows the optimized vehicle decelerationdeformation characteristics that minimized the chest acceleration and the chest deflection of the Hybrid III dummy model, respectively.…”

Section: Crash Dummy and Human Fe Modelmentioning

confidence: 99%

“…Vehicle deceleration-deformation characteristics optimized by GA at 50 km/h. The vehicle deceleration-deformation characteristics obtained by steepest decent method (SDM) are also presented for comparison (Mizuno et al 2014).…”

Section: Simple Spring-mass Modelmentioning

confidence: 99%

See 2 more Smart Citations

Crash Pulse Optimization for Occupant Protection at Various Impact Velocities

Ito

Yokoi

Mizuno

2014

Traffic Injury Prevention

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Objective: Vehicle deceleration has a large influence on occupant kinematic behavior and injury risks in crashes, and the optimization of the vehicle crash pulse that mitigates occupant loadings has been the subject of substantial research. These optimization research efforts focused on only high-velocity impact in regulatory or new car assessment programs though vehicle collisions occur over a wide range of velocities. In this study, the vehicle crash pulse was optimized for various velocities with a genetic algorithm. Method: Vehicle deceleration was optimized in a full-frontal rigid barrier crash with a simple spring-mass model that represents the vehicle-occupant interaction and a Hybrid III 50th percentile male multibody model.To examine whether the vehicle crash pulse optimized at the high impact velocity is useful for reducing occupant loading at all impact velocities less than the optimized velocity, the occupant deceleration was calculated at various velocities for the optimized crash pulse determined at a high speed.The optimized vehicle deceleration-deformation characteristics that are effective for various velocities were investigated with 2 approaches.Results: The optimized vehicle crash pulse at a single impact velocity consists of a high initial impulse followed by zero deceleration and then constant deceleration in the final stage. The vehicle deceleration optimized with the Hybrid III model was comparable to that determined from the spring-mass model.The optimized vehicle deceleration-deformation characteristics determined at a high speed did not necessarily lead to an occupant deceleration reduction at a lower velocity.The maximum occupant deceleration at each velocity was normalized by the maximum deceleration determined in the single impact velocity optimization. The resulting vehicle deceleration-deformation characteristic was a square crash pulse. The objective function was defined as the number of injuries, which was the product of the number of collisions at the velocity and the probability of occupant injury. The optimized vehicle deceleration consisted of a high deceleration in the initial phase, a small deceleration in the middle phase, and then a high deceleration in the final phase.Conclusion: The optimized vehicle crash pulse at a single impact velocity is effective for reducing occupant deceleration in a crash at the specific impact velocity. However, the crash pulse does not necessarily lead to occupant deceleration reduction at a lower velocity. The optimized vehicle deceleration-deformation characteristics, which are effective for all impact velocities, depend on the weighting of the occupant injury measures at each impact velocity.

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Section: Discussionsupporting

confidence: 91%

Section: Crash Dummy and Human Fe Modelmentioning

confidence: 99%

See 1 more Smart Citation

Crash Pulse Optimization for Occupant Protection at Various Impact Velocities

Ito

Yokoi

Mizuno

2014

Traffic Injury Prevention

Self Cite

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“…At present, it is mainly focused on the research of crash energy management methods of the vehicle front-end structure based on engineering experience in the FRB impact condition [27][28][29]. Considering the impact force transmission characteristics of FRB condition, the front-end structure of the vehicle is divided into space, and the crash pulse is decomposed according to the sub-space as the energy absorption target [12].…”

Section: Introductionmentioning

confidence: 99%

Frontal Vehicular Crash Energy Management Using Analytical Model in Multiple Conditions

et al. 2022

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When it comes to frontal vehicular crash development, matching the stiffness of the front-end structures reasonably, i.e., impact energy management, can effectively improve the safety of the vehicle. A multi-condition analytical model for a frontal vehicular crash is constructed by a three-dimensional decomposition theory. In the analytical model, the spring is used to express the equivalent stiffness of the local energy absorption space at the front-end structure. Then based on the analytical model, the dynamic responses and evaluation indexes of the vehicle in MPDB and SOB conditions are derived with the input of the crash pulse decomposition scheme. Comparing the actual vehicle crash data and the calculation results of the proposed solution method, the error is less than 15%, which verifies validity of the modeling and the accuracy of the solution. Finally, based on the solution method in the MPDB and the SOB conditions, the sensitivities of the crash pulse decomposition scheme to evaluation indexes are analyzed to obtain qualitative rules which guide crash energy management. This research reveals the energy absorption principle of the front-end structure during the frontal impact process, and provides an effective optimization method to manage the multiple conditions of the vehicle crash energy such as the FRB (frontal rigid barrier), the MPDB (mobile progressive deformable barrier), and the SOB (small overlap barrier).

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“…At present, it is mainly focused on the research of crash energy management methods of vehicle front-end structure based on engineering experience in the FRB impact condition [27][28][29] . Considering the impact force transmission characteristics of FRB condition, the front-end structure of the vehicle is divided into space, and the crash pulse is decomposed according to the sub-space as the energy absorption target [12] .…”

Section: Introductionmentioning

confidence: 99%

Crash Energy Management of Vehicle Front-end Structures Considering Multiple Conditions: Modelling and Solution Method

Wang

Zhang

Wang

2021

Preprint

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For the vehicle frontal crash development, matching the stiffness of the front end structures reasonably, i.e., impact energy management, can effectively improve the safety of vehicle. A multi-condition analytical model for vehicle frontal crash is construct by three dimensional decomposition theory. In the analytical model, the spring is used to express the equivalent stiffness of the local energy absorption space at the front-end structure. Then based on the analytical model, the dynamic responses and evaluation indexes of the vehicle in MPDB and SOB conditions are derived with input of crash pulse decomposition scheme. Comparing the actual vehicle crash data and the finite element simulation results with the calculation results of the proposed solution method, the error is less than 15%, which verifies validity of the modeling and the accuracy of the solution. Finally, based on the solution method in the MPDB and the SOB conditions, the sensitivities of crash pulse decomposition scheme to evaluation indexes are analyzed to obtain qualitative rules which guide crash energy management. This research reveals the energy absorption principle of front-end structure during the frontal impact process, and provides an effective tool to manage the vehicle crash energy considering multi-condition.

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Optimization of Vehicle Deceleration to Reduce Occupant Injury Risks in Frontal Impact

Cited by 12 publications

References 8 publications

Crash Pulse Optimization for Occupant Protection at Various Impact Velocities

Crash Pulse Optimization for Occupant Protection at Various Impact Velocities

Frontal Vehicular Crash Energy Management Using Analytical Model in Multiple Conditions

Crash Energy Management of Vehicle Front-end Structures Considering Multiple Conditions: Modelling and Solution Method

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