• Proceedings of the KSME Conference
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• 2001.11a
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• pp.489-494
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• 2001

This paper develops a finite element model for frontal crash analysis of a large-sized truck. It is composed of 220 parts, 70,041 nodes and 69,073 elements. This paper explains only major parts' models in detail such as frame, cab, floor, and bumper which affect on crash analysis a lot. In order to prevent penetration not only at a part itself but also between parts, all contact areas are defined using type-36, self-impact type. The developed model's reliability is validated by comparing simulation and crash test results. The results used for model validation are vehicle pulses at B-pillar, and frame and deformation of frame and cab. The frontal crash simulation is performed with the same conditions as crash test. And, it is performed using PAM-CRASH installed in super-computer SP2. The developed model whose reliability is verified may be used as a base to develop a finite element model for occupant behavior and injury coefficient analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.101-107
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• 2004

Recently the objective of vehicle design was focused on the crash safety and the energy saving. For the energy saving vehicle structures must be light weight, but for the crash safety some energy absorbing elements must be added. In this paper hybrid structure which consists of a steel and a FRP was studied on the energy absorption characteristics under the impact load by finite element method. Test results of the other researchers were compared with that of computer simulation on this simple hybrid structure. Side rail of vehicle front structure was replaced with hybrid materials for the application of the vehicle structure. 35mph frontal crash simulation was performed with hybrid structure and with conventional steel structure. By the adoption of hybrid structure, the improvement of energy absorption characteristics and reduction of weight was observed under the frontal crash simulation.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.6
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• pp.583-590
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• 2015

Automobile crash optimization is nonlinear dynamic response structural optimization that uses highly nonlinear crash analysis in the time domain. The equivalent static loads (ESLs) method has been proposed to solve such problems. The ESLs are the static load sets generating the same displacement field as that of nonlinear dynamic analysis. Linear static response structural optimization is employed with the ESLs as multiple loading conditions. Nonlinear dynamic analysis and linear static structural optimization are repeated until the convergence criteria are satisfied. Nonlinear dynamic crash analysis for frontal analysis may not have boundary conditions, but boundary conditions are required in linear static response optimization. This study proposes a method to use the inertia relief method to overcome the mismatch. An optimization problem is formulated for the design of an automobile frontal structure and solved by the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.314-314
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• 2000

This study deals with the analysis of the effectiveness of a safer belt in frontal crash. ATB, Articulated Total Body, program is used as a dynamics solver of the occupant model. ATB is a public code, however, the program is somewhat cumbersome to use due to lack of sufficient user interface. A preprocessor and a postprocessor are, therefore, developed for a user friendly graphic interface in Windows environment. Dialog boxes are used for an interface with GEBOD, Generator of Body Data, for human anthropometry and with ADAMS for vehicle dynamics. It is found through three test simulations that simulated results are in good agreement with those obtained by ATB. The effect of the initial slack of safety belt is investigated for frontal crash using the developed program.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.49-54
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• 2014

Development in vehicle industry could increase interest in children's safety recently. However the research of children safety is not being conducted as many as that of adult's. Especially the basic study for the vehicle crash on-board children was not much. This study focused on the effect of seatbelt anchorage points to evaluate children's safety in frontal crash. The current regulation of the seatbelt anchorage points is suitable for ranged from female 5% to male 95%. The assessment of children's safety at buckle up of no used CRS(child restraint system) was performed using frontal sled tests. The frontal crash pulse in sled tests was designed to the average of about 30 KNCAP frontal crash pulses. To reduce number of experiments, DOE is used. The Q6 child dummy and standard seat in UN R 129 were used. According to the analysis of test results, children's safety has been influenced by the points of seatbelt anchorage.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1156-1161
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• 2008

Nonlinear dynamic analysis is generally used in automobile crash analysis and structural optimization considering crashworthiness uses the results of nonlinear dynamic analysis. Automobile crash optimization has high nonlinearity and difficulty in calculating sensitivity. Recently the equivalent static load (ESL) method has been proposed in order to overcome these difficulties. The ESL is the static load set generating the same displacement field as the nonlinear dynamic displacement field at each time step in dynamic analysis. From various researches regarding the ESL method, it has been proved that the ESL method is fairly useful. The ESL method can mathematically optimize a crash optimization problem through nonlinear analysis and well developed static optimization. The ESL is applied to nonlinear dynamic structural optimization of the automobile frontal impact problem. An automobile bumper is optimized. The mass of the structure is minimized while some constraints are satisfied.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.226-232
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• 2000

This paper develops a finite element model for studying the crashworthiness analysis of a mid-size truck. A simulation for a truck frontal crash to a rigid barrier using the model is performed with PAM-CRASH installed in super computer SP2. Full vehicle model is composed of 86467 shell elements, 165 beam elements and 98 bar elements, and 86769 nodes. The model uses four material model such as elastic, elastic-plastic(steel), rigid and elastic-plastic(rubber) material model which are in PAM-CRASH. Frame and suspension system are modeled with 28774 shell elements and 31412 nodes. Cab is modeled with 34680 shell elements and 57 beam elements, and 36254 nodes. Bumper is modeled with 2262 shell elements, and 2508 nodes. Axle, steering shaft, etc are modeled using beam or bar elements. Mounting parts are modeled using rigid bodies. Bodies are interconnected using nodal constrains or joint options. To verify the developed model, frontal crash test with 30mph velocity to a rigid barrier is carried out. In the crash test, vehicle pulse at lower part of b-pillar is measured, and deformed shapes of frame and driver seat area are photographed. Those measured vehicle pulse and photographed pictures are compared those from the simulation to verify the developed finite element model.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.177-185
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• 2000

The deformation characteristics is one of the major factors to resume the crash configuration in collision accident reconstruction. Crash analysis are carried out using finite element method and body stiffness equations representing force-deformation relationship are derived, Two different crash conditions : 1) frontal barrier impact 2) frontal impact between cars are given for the derivation of the equations. The stiffness coefficient of equation by method 2) is larger than that by method. 1). Crash analysis between two vehicles is accomplished with three crash angles and three velocities for each angle condition. The deformations are measured for six selected points and deformation energies are calculated using the derived equations. Equation by method 2) results in better estimation of deformation energy than that by method 1) for all crush configurations. The estimated energies can be utilized as one of indices to identify the type of the collision accident result.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.213-216
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• 2008

Sled test id widely used to evaluate the performance of occupant's safety system in frontal crash environment without having to conduct a full-scale crash test. Steel bar breaking system is used to generate deceleration profile which is experienced by passengers in frontal crash. In this study, deformation analyses of steel bars were conducted using a commercial FE code. Several guidelines were proposed to improve the accuracy of simulation.

• Journal of Auto-vehicle Safety Association
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• v.9 no.2
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• pp.20-25
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• 2017

KNCAP is a program to evaluate the automobile safety, providing consumer vehicle safety assessment results. The safety evaluation tests are Frontal Impact, Offset Frontal Crash, Side Crash, Side Pole Crash, Rear Impact. This is the study of the offset frontal impact safety evaluation. Currently, IIHS is performing a small overlap test. NHTSA plans to implement the oblique moving deformable barrier test. Euro-NCAP plans to implement a mobile frontal impact test. Simulation is used to compare occupant behavior and injury. We have investigated whether the introduction of the test at KNCAP is necessary. The dummy model used in the simulation was the 50th percentile male Hybrid III dummy.