Showing papers on "Crash box published in 2012"

Bumper Assembly for Vehicle

Abstract: A bumper assembly for vehicle may include a first side member disposed in each of both sides of a vehicle body in a longitudinal direction thereof, a second side member coupled to an external surface of the first side member, a fender member having one side coupled to an external side of the second side member, a member flange connected to front ends of the first and second side members respectively, a mounting flange coupled with the member flange, a first crash box having a rear end connected to the mounting flange, a second crash box having a rear end connected to the mounting flange, and a bumper beam having both distal sides, each of which may be coupled to front ends of the first and second crash boxes

Crashworthiness Design Optimization Using Equivalent Static Loads

Abstract: Crashworthiness is an issue that should be considered when designing a passenger vehicle to ensure the occupants' safety in a vehicle accident. Many governments and insurance companies around the world suggest conditions relating to passenger safety in designing vehicles, and regulations that include the conditions have been utilized. The suggested regulations reflect the crashworthiness of structures in order to consider passenger safety. Therefore, these conditions should be used as objective functions or constraints when optimizing a vehicle structure. However, it is difficult to apply gradient-based optimization methods to crash optimization problems because of the large non-linearities of the problems which should be considered in the time domain. The non-linearities and oscillation of the responses make it difficult to calculate the sensitivity information. Therefore, a design method regarding the crash optimization problem needs to be developed. A crash problem should consider the crashworthiness of the vehicle. That is, a design problem should be solved regarding the crash energy conveyed from the outside and injuries to the human body. In the present research, a crashworthiness design optimization method using equivalent static loads that considers the strain energy and injuries of the human body is proposed. The equivalent static loads method for non-linear static response structural optimization (ESLSO) is modified to handle responses imposed on the strain energy and the head injury criterion (HIC) responses. The proposed ESLSO is verified through three practical examples. Design optimization of a crash box and a knee bolster are carried out to maximize absorbed impact energy, and size optimization of a frontal structure of a simplified vehicle is performed to reduce head injury. In verifying the proposed method, traditional optimization methods such as the response surface method are used. The excellence and usefulness of the proposed crashworthiness optimization method are proved by successfully applying it to a crash problem and improving the crashworthiness of the vehicle. Language: en

Bumper assembly and method

Abstract: A bumper assembly includes a bumper beam having a bumper beam surface extending along a bumper plane X and a crash box including a crash box surface extending along a crash box plane Y. One of the bumper beam and the crash box includes an alignment joint to mate the bumper beam and the crash box and dispose the surfaces in abutting and aligned relationship relative to one another for establishing a linear load path extending linearly along the planes X, Y. A method of assembling a bumper assembly includes the steps of mating the bumper beam and the crash box about the alignment joint and connecting the bumper beam and the crash box together along the alignment joint. The step of connecting the bumper beam and the crash box includes friction stir welding the bumper box and the crash box together along the alignment joint.

Impact absorbing device for vehicle

Abstract: An impact absorbing device for a vehicle may include a bumper beam having a hollow cross section which extends in a traverse direction of the vehicle, and crash boxes interposed between the bumper beam and a vehicle body in a longitudinal direction of the vehicle at both distal portions of the bumper beam, wherein rear surfaces of the both distal portions in the bumper beam include an opening formed so as to communicate with the hollow cross section of the bumper beam, wherein a rib may be formed at the opening of the bumper beam in a traverse direction of the opening, and wherein the crash box includes a front tip end inserted through the opening while being fitted to the rib to extend up to an inside of the hollow cross section, and a rear tip end mounted to the vehicle body in the longitudinal direction of the vehicle.

Vehicle end section structure

Abstract: In a frontal vehicle collision, an orthogonal cross-section of a crash box, taken orthogonally to the vehicle front-rear direction, deforms into a hexagonal shape. Due to this deformation of the orthogonal cross-section, new ridge lines are formed at an upper face portion and a lower face portion, running from the vicinity of both end portions in a vehicle width direction of vehicle rear end portions to the vicinity of both end portions in the vehicle width direction of respective join portions S. The strength of the crash box in the vehicle front-rear direction increases due to the increased number of ridge lines in the vehicle front-rear direction (axial direction). Load generated during crushing of the crash box in the vehicle front-rear direction therefore increases, as a result of which the energy absorption amount of the crash box increases. Namely, the impact absorption performance of the crash box is improved.

Crash box for vehicle and bumper device for vehicle and impact absorption structure for vehicle

Abstract: PROBLEM TO BE SOLVED: To provide a crash box for a vehicle capable of sufficiently performing weight saving while ensuring excellent impact absorption performance, and easily tuning an impact absorption characteristicSOLUTION: A cylindrical resin molding 10 includes a honeycomb structure in which a plurality of cylindrical cells 12 with the area of a cross section perpendicular to a hexagonal axis gradually increasing toward one side in an axial direction share at least one side 14 and are arranged mutually adjacently, and a through hole 20 for adjusting strength to plastic deformation in an axial direction is formed in the cylindrical resin molding 10

Bumper assembly for motor vehicle, has extensions, which come in corresponding latch for engagement in event of crash, and are spread apart by actuator in event of pedestrian collision

Abstract: The bumper assembly (1) has a pedestrian protection (6), which is particularly partially covered from a metallic material, where a jacket (10) has two extensions (11) towards a crash box (3). A cross element (2) and the crash box partially overlap. The extensions come in a corresponding latch (12) for engagement in the event of crash, and are spread apart by an actuator in the event of a pedestrian collision, so that the pedestrian protection dampens the pedestrian collision. The extensions are moved over longitudinal direction to the latch in motor vehicle.

Application of functionally graded materials for severe plastic deformation and smart materials : experimental study and finite element analysis

Abstract: Functionally graded materials (FGMs) refer to the composite materials where the compositions or the microstructures are locally varied so that a certain variation of the local material properties is achieved. Determination of compositional gradient and the process of making an FGM are dependent on its intended use. In this study, new possible applications of FGM and its production process were investigated. Three possible application of FGM were proposed. First, the novel technique in producing ultra fine grain of difficult-to-work materials by equal-channel angular pressing (ECAP) process at ambient temperature was developed by using FGM. For this study, Ti as the difficult-to-work material was tightly encapsulated in a hollow host material made of Al-based FGM matrix. The Al-based FGM as a host material assists the deformation of Ti. The ECAP process was simulated by the finite element method (FEM) to determine the appropriate compositional gradient of Al-based FGM and the position to embed Ti wire. FEM was conducted with Ti embedded into a different host material type as well as different die channel geometry. The strain distribution of the specimen after a single ECAP pass was analyzed. From the obtained results, it is found that the strain distribution in Ti is strongly influenced by the host material and the shape of the die channel. An experimental work was carried out to confirm the ability of the proposed technique in producing ultra fine grain of Ti. The host material was prepared by embedding Al-Al3Ti alloy into Al. Three types of the Al-Al3Ti alloys with different Al3Ti volume fractions were used to prepare the host materials. ECAP for specimens was carried out for up to eight passes by route A. The microstructure and hardness of ECAPed specimens were investigated. The changes in microstructure and the increase in the hardness value of Ti with increased number of ECAP passes are evidences showing that Ti is successfully deformed by this technique. Second, new types of FGM crash boxes with stepwise strength gradient in longitudinal directions were proposed. The property of the proposed FGM crash boxes were analyzed using FEM. Crash behavior of the crash box under axial quasi-static and dynamic impact loads were studied. The obtained load-displacement curves and the crash failure patterns then were evaluated to assess the effect of the stepwise strength gradient of the crash-box. Moreover, four different shapes of cross-sectional i.e. square, circle, pentagon and hexagon were considered. The results show that the FGM crash box is superior to than the homogeneous crash box in overall crashworthiness. Although there were no trigger mechanism introduced, the FGM crash boxes experience the progressive crushing initiated at the impact side. Third, the FGMs were applied in pipe and pressure vessel field. A solution procedure for finite element thermo-visco-plasticity and creep analysis in an FGM thick-walled pressure vessel subjected to thermal and internal pressure was presented. The thickwalled pressure vessel was replaced by a system of discrete rectangular cross-section ring elements interconnected along circumferential nodal circles. The property of FGM was assumed to be continuous function of volume fraction of material composition. The thermo-visco-plasticity and creep behavior of the structures were obtained by the use of an incremental approach. The obtained results show that the material composition significantly affects the stress as a function of time at the inside and outside surface of thick-walled pressure vessel. The use of FGM can adjust the stress distribution in the structure. Moreover, one of the FGM fabrication method, centrifugal casting, was investigated. Two types of centrifugal casting method namely, centrifugal solid-particle method (CSPM) and centrifugal mixed-powder method (CMPM), were used to fabricate Al/SiC FGM. Formations of graded distribution of SiC particles within molten Al by CSPM and CMPM under huge centrifugal force were examined and simulated. The movement of SiC particles in viscous liquid under centrifugal force was explained theoretically based on Stoke�s law. The effect of composition gradient of particles on viscosity was taken into account. Also, the effect of temperature distribution on viscosity and density were considered. A computer code to simulate the formation of compositional gradient in an Al/SiC FGM manufactured by CSPM and CMPM was developed. From the obtained results, it was found that the SiC particles can be graded from inner to outer surface of Al/SiC FGM by CSPM. Meanwhile by CMPM, the SiC particles can be dispersed on the surface of Al/SiC FGM. The graded distribution in Al/SiC FGM under huge centrifugal force was significantly affected by the mold temperature but less affected by the initial temperature of molten Al and casting atmosphere.

Crash box for absorbing impact energy

Abstract: The invention discloses a crash box (1) for a motor vehicle for absorbing impact energy during a crash, said crash box comprising an outer section (2) To obtain a crash box (1) that both contributes to a reduction in weight and has at the same time an increased absorption potential for absorbing impact energy, an inner section (3) is located in the outer section (2), the inner section (3) and the outer section (2) are interconnected and at least one gap (4) between the inner section (3) and the outer section (2) is filled with a filler material (5)

Frontal Structure Improvement on Car Based on RCAR Impact Test

Abstract: The objective of this study is to optimize crash-box so as to improve low-speed crash energy absorption For this purpose, a vehicle finite element (FE) model was established and validated by the acceleration curve of the back seat in 100% front impact and 40% offset impact According to the RCAR rule, the simulation at low-speed impact of 16km/h was carried out to evaluate the crashworthiness of the car Based on the simulation results, a crash-box was designed and the parameter study was carried out to improve the energy absorption of bumper and crash box by using the orthogonal experiment design and the overall balance method The results showed that the improved frontal structures can be good to meet the requirement of RCAR regulations

Vehicle front structure

Abstract: PROBLEM TO BE SOLVED: To provide a vehicle front structure in which right and left directional deformation of a crash box can be suppressed when right and left moment is applied to the crash box during vehicle driving.SOLUTION: A pair of right and left crash boxes 16 are provided between a front side member 12 and a front bumper reinforcement 24. The crash box 16 is provided with a cylindrical impact absorbing part 18 and a connection plate 20. The impact absorbing part 18 is provided with a first panel member 30 which has a roughly U-shaped cross section and is opened toward the inside of the vehicle, and a second panel member 32 which has a roughly U-shaped cross section and is opened toward the outside of the vehicle. The first panel member 30 is connected to upper and lower superposed parts 34, 36 of the second panel member 32 by spot welding 40, and formed into a closed cross section. The impact absorbing parts 18 are symmetrical in vehicle plan view, and the welding parts at the upper and lower superposed parts 34, 36 are disposed in different diagonal directions of the pair of right and left crash boxes 16.

Al and Mg-Based Lightweight Metallic Materials for Automobile Applications

Abstract: The need for the development of eco-friendly and fuel efficient transport devices demands the use of high performance lightweight materials. A few attractive features of lightweight materials include low density and high specific strength and modulus. There are a number of material systems in this category including Al- and Mg- based alloys and their composites, Al foam, sandwich panels etc. In this study, an attempt has been made to highlight some of our R&D efforts pertaining to the development of Al metal matrix composite (MMC), Mg alloys, Al foam and components thereof like automobile brake drum, crash box etc. Al foam could be used for crash box and noise and vibration attenuation applications. It is evident from the results that the metal foam has the highest loss factor and damping coefficient as compared to the other investigated materials. Foam filled tubes exhibit damping capacity ∼9 to 10 times higher than the dense steel bars or hollow steel tube. Al MMC has drawn considerable attention of the automobile sector for developing brakedrums, pistons, cylinder liners, connecting rods etc. because of their interesting combination of properties such as high specific strength and specific modulus, better wear resistance, good corrosion resistance etc. The developed MMC brake drum is in a process of being tested. Mg alloys also find applications in the transportation sector in the form of engine/gear box casings, bearing covers etc. Rolling behaviour of Mg alloys has also been studied with improvement in properties after rolling.

Effect of Bead Shape in Aluminum Crash Box for Effective Impact Energy Absorption Under Low- Velocity Impact Condition

Abstract: 에 의하면, 범퍼레일 사이에 크래쉬 박스(Crash Box)가 삽입된 구조가 대부분의 차량에 적용되고 있는 일반적인 범퍼체결 구조와 비교해 우수한 차량의 손상성을 나타낸다. 본 연구에서는 Fig. 1에 나타낸 알루미늄 프론트바디에서 범퍼와 프론트 사이드 멤버 사이에 위치 Key Words : Aluminum Crash Box(알루미늄 크래쉬 박스), Low Velocity Impact(저속충돌), Front Side Member (프론트 사이드 멤버), Impact Energy(충돌에너지) 초록: 알루미늄 크래쉬 박스는 저속충돌조건에서 프론트 사이드 멤버를 변형을 방지하기 위한 부품이다. 본 연구에서는 저속충돌조건에서 비드형상이 알루미늄 크래쉬 박스의 충돌성능에 미치는 영향을 분석하였다. Edge concave, surface convex와 surface concave 타입의 비드형상들에 대한 충돌해석 및 실험을 수행하여 비드가 없는 normal 타입의 알루미늄 크래쉬 박스의 충돌성능과 비교분석하였다. 충돌성능은 저속충돌조건에서 크래쉬 박스의 초기 최대하중 및 충돌에너지 흡수능으로 평가하였다. 이를 검증하기 위해 알루미늄 크래쉬 박스와 결합된 프론트 사이드 멤버에 대해 저속충돌실험 수행하고, 이를 분석하였다. Surface concave 타입의 비드가 삽입된 알루미늄 크래쉬 박스 경우, 프론트 사이드 멤버의 변형을 방지할 수 있음을 확인하였다. Abstract: The purpose of this study is to investigate the effects of the bead shape on the crash performance of an aluminum crash box under a low-velocity impact condition. The initial peak load and impact energy absorption of a crash box with three types of bead shapes—edge concave, surface convex, and surface concave type—were studied through an FE analysis and an experiment. In addition, the effects of the bead shapes on the crash performance of the crash box were verified through a low-velocity-impact test with a front side member assembled with an aluminum crash box. The initial peak load of the surface-concave-type crash box was reduced by the bead, and therefore, deformation of the front side member at initial contact could be prevented. Furthermore, there was no deformation of the front side member after the impact test because the crash box with a surface-concave-type bead absorbed all the impact energy.

Bumper system with towing device

Abstract: The arrangement has a cross beam at which crash box is coupled, and a retainer (1) provided for a releasably linked towing hook. The retainer has a flange plate (2) and a hole element (3) for retaining the towing hook, where the flange plate is coupled at the crash box. The flange plate is coupled between the crash box and a longitudinal beam by a fastening bolt. The retainer is made of tempered steel. The hole element has a hollow section that is coupled indirectly or directly with a threaded sleeve (4).

Trolley Test와 CAE를 이용한 Bumper System 개발

Abstract: Crash box in the bumper system has important role of absorbing energy. The parameters on the absorbing crash energy are thickness, shape and material. These are major influence on absorbing energy. Therefore, three factors should be decided initial stage. In this paper, we present bumper system development process that is gone on until correlation with physical result and CAE result. Initial criteria should be determined before physical test and CAE analysis. First stage is squeezing test. Second stage, Crash box that is satisfied performance is applied to trolley FE model. And the result of physical test is correlated with the result of CAE analysis. Last stage, the result of trolley CAE analysis is correlated with the result of full vehicle CAE analysis.

Rear bumper beam for CHB011

Abstract: The utility model discloses a rear bumper beam for CHB011. The rear bumper beam comprises a beam main body and crash boxes, wherein a crash box is fixed at each of the two ends of the beam main body made from glass mat reinforced thermoplastics (GMT), is embedded and fixed in a vehicle body, and has a U-shaped structure made from an elastic material. The utility model has the advantages that: the rear bumper beam has high cushion performance; and the service life of the rear bumper beam is prolonged.

The crash box used a car

Abstract: PURPOSE: A crash box for a vehicle is provided to prevent the deformation of a side member by installing a plate between the side member and the crash box. CONSTITUTION: A crash box for a vehicle comprises a crash box body(20) and a reinforcement(50). The crash box body is installed between a back beam(14) and a side member for absorbing impact. The ridges(21) and the gullies(22) of the crash box body are corrugated repetitively. The reinforcement is formed in a closed section symmetrical to an opening side and curved toward the inside of the crash box body. Protruded portions(51) and recessed portions(52) are formed in the whole body of the reinforcement.

Impact absorbing member for vehicle and vehicle end structure

Abstract: PROBLEM TO BE SOLVED: To effectively improve impact absorbing performance.SOLUTION: When a body 102 of a crash box 100 is compressed in an axial direction and deformed (crushed) like a bellows, flanges 162A, 166A closer to each other along inner surfaces 112M, 114M of sidewalls 112, 114 suppress the sidewalls 112, 114 from being deformed inward. Accordingly, as the generation of the deformation of an edge line is suppressed, the sidewalls are ideally suppressed in the axial direction and deformed (crushed) like the bellows, impact absorbing performance is effectively improved.

Crash absorbing box for vehicle

Abstract: PURPOSE: A crash box for vehicles is provided to effectively support weight for a center test of the RCAR(Research Council for Automobile Repairs) because a square cross-section is partially applied to a stiffness reinforcing part. CONSTITUTION: A crash box for vehicles(100) is installed on both ends of a bumper beam disposed in a width direction and the crash box absorbs the collision energy of a vehicle crash. The crash box has a hollow heptangular section. One interior angle among corners of the section is at 90 degrees to form a stiffness reinforcing part(R). The stiffness reinforcing part is placed toward the interior of the vehicle. A rigid gusset is located towards the inner side direction [toward the interior side] of the vehicle.

A Research on the Impact Energy-absorbing Capacity of the Aluminum Alloy Energy-absorbing Box of the Bumper

Abstract: In order to improve the vehicle bumper energy-absorbing characteristics of the vehicle aluminum crash box and realize the lightweight design,the finite element model of the aluminum crash box was built.The crash simulation was carried out based on the software Ls-DYNA.The energy-absorbing characteristics between five different cross-sectional shapes of the single cavity of aluminum alloy energy-absorbing box and four kinds of multiple-cavity aluminum alloy energy-absorbing box was studied in Contrasts.The thickness of the energy-absorbing box on the influence of energy-absorbing characteristics were discussed.The study results showed that the energy-absorbing box with cross-section of octagonal shape has the best energy-absorption ability in the five kinds of single cavity structures.The multiple-cavity energy-absorbing box has better performance than the single cavity structure in energy absorbing characteristics.Within a certain range,and along with the increase in thickness of the energy-absorbing box,energy absorption and specific energy absorption increases significantly.

Automobile Box Structure Optimization and Simulation

Abstract: This paper mainly designs several projects to analyze the deformation of crash box. Through analyzing the crushing distance, energy absorption and axial force variation, which is under different schemes and low crash speed, gets that: a front crash box slot is necessary; Filling foam allows the specimen to absorb more energy and makes the carrying capacity changing more stably. Finally, we compared simulation results with the experimental results, and on this basis, providing improvement program means.

Shock absorber for vehicles

Abstract: PURPOSE: A buffering device for a vehicle is provided to secure the safety of pedestrians and prevent damage to vehicles by absorbing impact energy according to situations through foam with different foaming ratios inserted in a crash box. CONSTITUTION: A buffering device for a vehicle comprises a carrier(110), a bumper back beam(120), and a multi-stage buffer unit(150). The bumper back beam is installed on the front side of the carrier. The multi-stage buffer unit connects the bumper back beam to the carrier and reduces an impact, which is transmitted from the bumper back beam in a crash, in multiple stages.

Holder assembly for holding cooling module at body of passenger car for cooling internal combustion engine, has holding element indirectly supported at upper side of crash box, where upper side points to vehicle vertical direction

Abstract: The assembly (10') has a crash box (26) extending in a vehicle longitudinal direction, and a holding element (32) indirectly supported at an upper side (40) of the crash box, where the upper side points to a vehicle vertical direction. The holding element comprises a retaining opening and upper and lower holding parts (34, 36), where the crash box is retained in the opening. The holding element is connected with a support frame (28) of a cooling module (12') through an oscillation decoupling element, where a cooling element (30) of the cooling module is held at the support frame.

후방 저속 충돌 성능 향상을 위한 c/box 설계에 관한 연구

Abstract: The aim of this study is to optimize rear crash box so as to reduce damage on car body structure from low-speed rear impact. According to RCAR low-speed structural crash test protocol, the analysis is carried out to evaluate the damageability of the car. A study of Correlation between bead parameters and performance is carried out by sensitivity analysis. After that, an optimal rear crash-box is designed by response surface method(RSM). The analysis results show that the improved rear crash box can reduce 47% of damage on body structure.