Browse Topic: Crashworthiness

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Crashworthiness Optimization of Hydraulic Excavator Cab Roof Rail and Safety Prediction: Finite Element Analysis and Experimental Validation2021-01-092504/06/2021
Off-road trucks, tractors and earth-moving machines are at high risk of accidents involving falling objects or rollovers. Therefore, these machines need proper protective structures to protect operators. This study investigates the crashworthiness optimization of a hydraulic excavator cab roof rail based on an improved bi-directional evolutionary structural optimization (BESO) method considering two different load cases (a lateral quasi-static load and an impact load from the top of cab, respectively). In the crashworthiness optimization problem, a weighted summation of external works done by the two different load cases is treated as the objective function while the volume of design domain is treated as the constraint. A mutative weight scheme is proposed to stabilize the optimization and balance the two load cases. Finite element (FE) model is established and two prototypes are fabricated based on the optimal design. Explicit FE analysis is used to predict the performance of roll
Ma, Chao, Liu, Zhe, Duan, Yuexing, Gao, Yunkai
Incidence and Mechanism of Head, Cervical Spine, Lumbar Spine, and Lower Extremity Injuries for Occupants in Low- to Moderate-Speed Frontal Collisions2021-01-090204/06/2021
Automotive accidents and subsequent personal injury claims incur substantial costs annually. While three-point restraint usage, dual-stage airbags, and knee bolster and side curtain airbags have become more ubiquitous and, in some cases, governmentally mandated for front seat occupants, occupant safety and injury risk assessment continue to be at the forefront of automotive innovation. In this study, we combined analyses of the National Automotive Sampling System Crashworthiness Data System (NASS-CDS; 2007-2015) and the Crash Investigation Sampling System (CISS; 2017) with data acquired from vehicle-to-vehicle crash tests conducted with instrumented anthropomorphic test device (ATD) occupants. Together, these analyses were used to compare and relate field injury rates with potential injury mechanisms in low- to moderate-speed frontal collisions. First, low- to moderate-speed (delta-V ≤ 24 km/h) frontal crash data from NASS-CDS and CISS were analyzed to estimate the rate of AIS 2+ and
Davis, M., Mkandawire, C., Brown, T., Pasquesi, S.
An Innovative Approach to Component Testing Using an Impact Sled2020-01-133104/14/2020
Historically, crash development component testing has been conducted using gravity-based vertical drop towers. The drop tower carriage is loaded to a specified weight, raised to a specific height to achieve an energy target, and dropped onto the part. This long-used approach has significant limitations with respect to achievable speed and energy, part orientation, impact angle, useable impact surface, component size, etc. With the wide variance in simulating today’s global crash scenarios, a better approach is being developed using an impact sled. The most significant advantage of this system is that there is a much higher achievable speed and energy which can be controlled with precise accuracy. This paper will provide an overview of the impact sled test system, as well as the methodology used to conduct the testing. The overview will include the challenges faced during the development of the impact sled, as well as the need for accurate and precise component fixturing methods
Kaleto, Helen, Pinelli, Alex, Briskey, Jacob P., Gizowski, John W., Reinitz, Aaron
Accident Statistical Distributions from NASS CDS - An Update2020-01-051804/14/2020
The National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) contains an abundance of field crash data. As technology advances and the database continues to grow over the years, the statistical significance of the data increases and trends can be observed. The purpose of this paper is to provide a broad-based, up-to-date, reference resource with respect to commonly sought-after crash statistics. Charts include up-to-date crash distributions by Delta-V and impact direction with corresponding injury severity rates. Rollover data is also analyzed, as well as historical trends for injury severity, belt usage, air bag availability, and the availability of vehicle safety technology.
Yaek, Jennifer L., Brown, Thomas, Goertz, Alan
Likelihood of Spinal Disc Herniations in Occupants Involved in Real World Side Impacts2020-01-052604/14/2020
The prevalence of spinal disc herniations in people with no spinal symptoms have been reported to increase with age; from about 20% in those below 40 years to about 30% in those above 40 years. Spinal disc herniations are usually associated with degenerative changes. Though rare, spinal disc herniations can also be caused by trauma. With an increasing number of older people on U.S. roads with a concomitant increase in the probability of getting injured in a vehicle collision, it is reasonable to expect that some of these occupants can present with clinical findings of spinal disc herniations after a side impact, and attribute these findings to the impact. In this study, we looked at the relationship between real world side impacts and the occurrence of spinal injuries, in particular disc herniations, in occupants involved in such impacts. We examined the reported occurrence of all spine injuries in side impact crashes in the National Automotive Sampling System - Crashworthiness Data
Lam, Tack, Ivarsson, B. Johan
The Effects of Front-Mounted Accessories on Air Bag Sensors and CrashworthinessJ2431_201910 (Current)10/09/2019
Almost all light trucks now are being manufactured with at least a driver side air bag and all will have dual air bags by 1998. The driving forces behind this feature are occupant safety, federal regulations, and competition in the industry. Along with the booming popularity of pickups and SUVs, they are commonly accessorized with a wide variety of products. Many accessories for four-wheel drives in particular are mounted on the front of the vehicle. These products include grille/brush guards, winches, snow plows, replacement bumpers, bicycle carriers, etc. Concerns have arisen over the compatibility of these accessories with the vehicle’s air bag system. The vehicle manufacturers are concerned because of their huge investment in design and crash test verification of the complete vehicle system and keen awareness of the federal regulations. The crushability of the front bumper and supporting structure are key elements in the system, so alterations to that area become logical concerns
Motor Vehicle Council
Safety Testing for AVs is Just Beginning19AVEP03_0903/01/2019
There is much work to be done in creating accurate, reliable tests for occupant crashworthiness tailored to new AV designs and seating configurations. NHTSA's plan to eventually update its New Car Assessment Program (NCAP) with new crash-test protocols is good news for both consumers and the mobility safety-systems industry. A revised NCAP will likely feature enhanced occupant safety testing as well as testing of active-safety features such as adaptive cruise control and automatic braking. It's also a positive step for autonomous vehicle (AV) developers. Studies show U.S. consumers are still resistant to the idea of self-driving cars, and such testing will provide the public with assurances that these vehicles are safe. This should serve to “warm up” consumers to the idea of a world with AVs, boosting demand and paving the way for an increasingly safer mobility future.
O'Connor, Christopher
Crashworthiness Prediction of a Composite Bumper System Using RADIOSS2018-01-011404/03/2018
In 2016 the United States Automotive Materials Partnership (USAMP) approached several software vendors with the desire to establish the current state-of-the-art of explicit finite element software for predicting the crash behavior of composite laminates as it relates to application in the automotive industry. The nonlinear explicit solver, RADIOSS, was included in the investigation. Coupon and generic component level test data were supplied to help with the development of material models. The innovation of the approach taken with RADIOSS was to use a numerical Design of Experiments (DOE) to simultaneously fit the various modes of material damage and failure for the composite material. Final correlation was to a series of sled tests completed on a composite bumper and crush cans. The RADIOSS prediction of the bumper system crash performance was “blind” because only after the simulation results were submitted to USAMP were the system level test data shared for comparison to the
Brink, John R., Kodwani, Ravi, Nakano, Rogerio
Studies on Impact Performance of Gradient Lattice Structure Applied to Crash Box2018-01-011904/03/2018
The conventional crash box with thin-walled column conceals some limitations on pedestrian protection and lightweight. The metallic NPR metamaterials designed in this study are based on re-entrant lattice structures. Re-entrant structures are known to be one main class of axenic structures that display negative Poisson’s ratio (NPR), which can be manufactured by 3D printing technology. This kind of metamaterial has good designability and can be used as the filling structure of the crash box to improve the crashworthiness of the car. This paper starts from the relations between geometric parameters of the metamaterial. Considering the deformation characteristics of the crash box, the structure were designed into some gradient types. The mechanical properties of different gradient structures under the same impact conditions were compared to find the proper gradient structures. Based on the studies, the gradient lattice structure is applied to the automobile crash box. We made some
Wu, Xian, Zhang, Shuxian, Shao, Jianwang
Analyses on Mechanical Properties of the Cylindrical Double-V Micro-Structure2018-01-011804/03/2018
The double-V micro-structures (DVMS) are a type of auxetic materials showing the negative Poisson’s ratio which can contract under compression different from the conventional materials. Due to the unique properties, it can have higher stiffness and better impact resistance with lightweight. In this paper, a cylindrical honeycomb tube based on the double-V unit cell is proposed. Firstly, the nominal Poisson’s ration and Young’s modulus in the longitudinal and circumferential directions are derived analytically. The effect of the geometry parameters of the DVMS tube on the mechanical properties is studied thoroughly. Also, the effect of the width in the radial direction on these mechanical properties is analyzed. Secondly, the finite element (FE) method is utilized to obtain the numerical solutions and verify the accuracy of the analytical solutions. The results show that there is a good agreement between the results obtained by the two methods when the width is smaller enough. With the
Gao, Qiang, wang, Yuanlong, Ma, Zheng-Dong, Zhong, Hong
Effects of AHSS Sheared Edge Conditions on Crash Energy Absorption in Component Bend Test2018-01-011304/03/2018
Edge fracture of advanced high strength steels (AHSS) can occur in both the stamping process and the crash event. Fracture due to poor sheared edge conditions in the stamping process was reduced with a recently developed optimal shearing process for AHSS. Currently, the improvement in the energy absorption due to the improved edge condition during crashes performed under different loading conditions had not been closely verified. The purpose of this study is to design and build a miniature component of AHSS and a three-point bending test for investigating the influence of various conditions of the sheared edge on the energy absorption in crashes. AHSS including DP600, TRIP780, DP980 and DP1180 were selected in the study. A small channel component was developed and fabricated using DP980 to simulate key features of the B-pillar. The exposed non-constrained, as-sheared edge was subject to stretch bending forces in three-dimensional space during the three-point bending test. Two bottom
Shih, Hua-Chu, Chen, Guofei
Automotive Crashworthiness Design Optimization Based on Efficient Global Optimization Method2018-01-102904/03/2018
Finite element (FE) models are commonly used for automotive crashworthiness design. However, even with increasing speed of computers, the FE-based simulation is still too time-consuming when simulating the complex dynamic process such as vehicle crashworthiness. To improve the computational efficiency, the response surface model, as the surrogate of FE model, has been widely used for crashworthiness optimization design. Before introducing the surrogate model into the design optimization, the surrogate should satisfy the accuracy requirements. However, the bias of surrogate model is introduced inevitably. Meanwhile, it is also very difficult to decide how many samples are needed when building the high fidelity surrogate model for the system with strong nonlinearity. In order to solve the aforementioned problems, the application of a kind of surrogate optimization method called Efficient Global Optimization (EGO) is proposed to conduct the crashworthiness design optimization. Based on
Fang, Yudong, Chen, Tao, Zhan, Zhenfei, Liu, Xu, Yu, Huili, Zhao, Hui
Investigation of the Samples Size Effects on Hybrid Surrogate Model Component Surrogates for Crashworthiness Design2018-01-102804/03/2018
Surrogate model based design optimization has been widely adopted in automotive industry. Hybrid surrogate model with multiple component surrogates is considered to be a better choice when simulating highly non-linear responses in vehicle crashworthiness analysis. Currently, the number of component surrogates has to be decided before-hand when constructing of a hybrid surrogate model. This paper conducts a comparative study on the performances of three popular hybrid modeling methods including heuristic computation strategy, and two kinds of optimal weighted surrogates. The effects of samples size on the number of individual surrogates that should be included into the final hybrid surrogate models for crashworthiness responses are investigated. Different hybrid modeling techniques and multiple validation criteria are evaluated. Some observations and conclusions on the selection of component surrogates in hybrid surrogate modeling are given in the end.
Chen, Chong, Zhan, Zhenfei, Dong, Wenxiang, YU, Huili, Zhao, Hui
Crushing Analysis and Lightweight Design of Tapered Tailor Welded Hybrid Material Tubes under Oblique Impact2016-01-040704/05/2016
The increasing demand for lightweight design of the whole vehicle has raised critical weight reduction targets for crash components such as front rails without deteriorating their crash performances. To this end the last few years have witnessed a huge growth in vehicle body structures featuring hybrid materials including steel and aluminum alloys. In this work, a type of tapered tailor-welded tube (TTWT) made of steel and aluminum alloy hybrid materials was proposed to maximize the specific energy absorption (SEA) and to minimize the peak crushing force (PCF) in an oblique crash scenario. The hybrid tube was found to be more robust than the single material tubes under oblique impacts using validated finite element (FE) models. Compared with the aluminum alloy tube and the steel tube, the hybrid tube can increase the SEA by 46.3% and 86.7%, respectively, under an impact angle of 30°. Parameter analyses were performed to reveal the influence of four geometrical variables on the
Wang, Da-Zhi, Cao, Guang-Jun, Qi, Chang, Sun, Yong, Yang, Shu, Du, Yu
Uncertainty Optimization of Thin-walled Beam Crashworthiness Based on Approximate Model with Step Encryption Technology2016-01-040404/05/2016
Crashworthiness is one of the most important performances of vehicles, and the front rails are the main crash energy absorption parts during the frontal crashing process. In this paper, the front rail was simplified to a thin-walled beam with a cross section of single-hat which was made of steel and aluminum. And the two boards of it were connected by riveting without rivets. In order to optimize its crashworthiness, the thickness (t), radius (R) and the rivet spacing (d) were selected as three design variables, and its specific energy absorption was the objective while the average impact force was the constraint. Considering the error of manufacturing and measurements, the parameters σs and Et of the steel were selected as the uncertainty variables to improve the design reliability. The algorithm IP-GA and the approximate model-RBF (Radial Basis Function) were applied in this nonlinear uncertainty optimization. In order to improve the accuracy of the RBF model, a new step-encryption
Du, Qianqian
Optimal Design of Cellular Material Systems for Crashworthiness2016-01-139604/05/2016
This work proposes a new method to design crashworthiness structures that made of functionally graded cellular (porous) material. The proposed method consists of three stages: The first stage is to generate a conceptual design using a topology optimization algorithm so that a variable density is distributed within the structure minimizing its compliance. The second stage is to cluster the variable density using a machine-learning algorithm to reduce the dimension of the design space. The third stage is to maximize structural crashworthiness indicators (e.g., internal energy absorption) and minimize mass using a metamodel-based multi-objective genetic algorithm. The final structure is synthesized by optimally selecting cellular material phases from a predefined material library. In this work, the Hashin-Shtrikman bounds are derived for the two-phase cellular material, and the structure performances are compared to the optimized structures derived by our proposed framework. In comparison
Liu, Kai, Xu, ZongYing, Detwiler, Duane, Tovar, Andres
Development of Beam Elements for Crashworthiness Analysis of Thin-Walled Beam Structures2016-01-040104/05/2016
In this paper, a new beam element is developed for the purpose of capturing thin-walled beam’s collapse mechanisms under dynamic load such as impact load and will be validated in the next phase. Such beam element can be used to create simplified finite element models for crashworthiness analysis and simulation and, therefore, will significantly reduce the modeling effort and computing time. The developed beam element will be implemented into LS-DYNA and validated through crashworthiness analysis and simulation. This paper introduces the approach of deriving the new element formulation.
Liu, Yucheng
Behavior of Adhesively Bonded Steel Double Hat-Section Components under Axial Quasi-Static and Impact Loading2016-01-039504/05/2016
An attractive strategy for joining metallic as well as non-metallic substrates through adhesive bonding. This technique of joining also offers the functionality for joining dissimilar materials. However, doubts are often expressed on the ability of such joints to perform on par with other mechanical fastening methodologies such as welding, riveting, etc. In the current study, adhesively-bonded single lap shear (SLS), double lap shear (DLS) and T-peel joints are studied initially under quasi-static loading using substrates made of a grade of mild steel and an epoxy-based adhesive of a renowned make (Huntsman). Additionally, single lap shear joints comprised of a single spot weld are tested under quasi-static loading. The shear strengths of adhesively-bonded SLS joints and spot-welded SLS joints are found to be similar. An important consideration in the deployment of adhesively bonded joints in automotive body structures would be the performance of such joints under impact loading. Due
Deb, Anindya, Chou, Clifford C., Srinivas, Gunti R., Gowda, Sanketh, Kurnool, Goutham
CFRP Crash Absorbers in Small UAV: Design and Optimization2015-01-246109/15/2015
The high number of hull losses is a main concern in the UAV field, mostly due to the high cost of on-board equipment. A crashworthiness design can be helpful to control the extent and position of crash impact damage, minimizing equipment losses. However, the wide use of composite materials has recently put the accent on the lack of data about the behavior of these structures under operative loads, such as the crash conditions. This paper presents the outcome of a set of tests carried out to achieve a controlled crush of UAV structures, and to maximize the Specific Energy Absorption. In this work, a small-scale experimental test able to characterize the energy absorption of a Carbon-fiber-reinforced polymer under compression was developed introducing self-supporting sinusoidal shape specimens, which avoid the need for complex anti-buckling devices. The specimens were produced with different auto-triggering configurations and fibers' continuity was interrupted in selected position and
Troiani, Enrico, Falaschetti, Maria Pia, Taddia, Sara, Ceruti, Alessandro
Fracture Prediction for Automotive Bodies Using a Ductile Fracture Criterion and a Strain-Dependent Anisotropy Model2015-01-056704/14/2015
In order to reduce automobile body weight and improve crashworthiness, the use of high-strength steels has increased greatly in recent years. An optimal combination of both crash safety performance and lightweight structure has been a major challenge in automobile body engineering. In this study, the Cockcroft-Latham fracture criterion was applied to predict the fracture of high-strength steels. Marciniak-type biaxial stretching tests for high-strength steels were performed to measure the material constant of the Cockcroft-Latham fracture criterion. Furthermore, in order to improve the simulation accuracy, local anisotropic parameters based on the plastic strain (strain dependent model of anisotropy) were measured using the digital image grid method and were incorporated into Hill's anisotropic yield condition by the authors. In order to confirm the validity of the Cockcroft-Latham fracture criterion, uniaxial tensile tests were performed. It was found that the accuracy of the
Takada, Kenji, Sato, Kentaro, Ma, Ninshu
Simulation Fidelity Improvement of H350 Lower Tibia Indices2015-01-057804/14/2015
Finite element dummy models have been more and more widely applied in virtual development of occupant protection systems across the automotive industry due to their predictive capabilities. H350 dyna dummy model [1] is a finite element representation of the Hybrid III male dummy [2], which is designed to represent the average of the United States adult male population. Lower extremity injuries continue to occur in front crash accidents despite increasing improvement of vehicle crashworthiness and occupant restraint system. It is therefore desirable to predict lower tibia injury numbers in front occupant simulations. Though lower tibia loading/index predictions are not studied as much as the FMVSS 208 regulated injury numbers, the tibia indices are injury criteria that need to be assessed during IIHS and Euro NCAP frontal offset occupant simulations. However during front crash simulations, it is very difficult to achieve good correlations or predictions of lower tibia loadings. A common
Li, Wei, Cheng, Yi-Pen, Furton, Lisa
Multi-Criteria Optimization of Foam Reinforced Thin-walled Tube Shape under Crashworthiness Requirements2015-01-136404/14/2015
The design of aluminum foam reinforced thin-walled tubes has garnered much interest recently due to the high energy absorption capacity of these tubes. As a new kind of engineering composite material, aluminum foam can hugely increase the crashworthiness capacity without sacrificing too much weight. In this paper, axisymmetric thin-walled hollow tubes with four different kinds of cross-sections (circular, square, hexagonal and octagonal) are studied to assess their performance for crashworthiness problems. It is found that the tube with square cross-section has the best crashworthiness performance under axial impact. To seek optimal designs of square aluminum foam reinforced thin-walled tubes, a surrogate modeling technique coupled with a multi-criteria particle swarm optimization algorithm has been developed, to maximize specific energy absorption (SEA) and minimize peak crash force (PCF). To improve the accuracy of the optimization process, meta-models of SEA and PCF were constructed
Wang, Tao, Wang, LIangmo, Wang, Yuanlong, Zou, Xiaojun, Guo, Fuxiang
The Front Center Airbag2013-01-115604/08/2013
General Motors and the Takata Corporation have worked together to bring to production a new, industry first technology called the Front Center Airbag which is being implemented on General Motors' 2013 Midsize Crossover Vehicles. This paper reviews field data, describes the hardware, and presents occupant test data to demonstrate in-position performance in far side impacts. The Front Center Airbag is an airbag that mounts to the inboard side of the driver front seat. It has a tubular cushion structure, and it deploys between the front seating positions in far side impacts, near side impacts and rollovers, with the cushion positioning itself adjacent the driver occupant's head and torso. This paper includes pictures of the technology along with a basic description of the design. In-position occupant performance is also described and illustrated with several examples. Single occupant and two front occupant far side impact test data are included, both with and without the airbag present
Thomas, Scott D., Wiik, Richard A., Brown, Jacqueline E.
An Assessment of the Effects of Passenger Vehicle Weight and Size on Accident and Fatality Risk Based on Data for 1991 through 2007 Model Year Vehicles2013-01-075704/08/2013
Quantifying the independent effects of vehicle weight and size on overall vehicle safety is necessary in order to assess the risks and benefits of vehicle weight reduction. This paper describes the results of one-stage and two-stage logistic regression analyses of the effects of passenger vehicle weight, wheelbase, track, and footprint on fatalities per accident, accidents per exposure (e.g., vehicle-miles-traveled), and fatalities per exposure using national and multi-state traffic accident and exposure databases. The analyses were accomplished in two phases. The first phase used 1995 though 2000 calendar year data for 1991 through 1999 model year vehicles. The second phase used 2002 through 2008 calendar year data for 2000 through 2007 model year vehicles. The overall fatalities per exposure results tend to confirm the one-stage results previously reported by NHTSA, however the new two-stage results provide additional insight into the independent effects of weight reduction and size
Van Auken, R. Michael, Zellner, John W.
Front Rail Crashworthiness Design for Front Oblique Impact Using a Magic Cube Approach2013-01-065104/08/2013
The front rail, as one main energy absorption component of vehicle front structures, should present steady progressive collapse along its axis and avoid bending collapse during the front oblique impact, but when the angle of loading direction is larger than some critical angle, it will appear bending collapse causing reduced capability of crash energy absorption. This paper is concerned with crashworthiness design of the front rail on a vehicle chassis frame structure considering uncertain crash directions. The objective is to improve the crash direction adaptability of the front rail, without deteriorating the vehicle's crashworthiness performance. Magic Cube (MQ) approach, a systematic design approach, is conducted to analyze the design problem. By applying Space Decomposition of MQ, an equivalent model of the vehicle chassis frame is generated, which simplifies the design problem. Based on this model, a two-layered front rail is proposed using a multi-step multi-domain topology
Hu, Sibo, Ma, Zheng-Dong, Qi, Chang, Ding, Yi
Structural Optimization of Thin-Walled Tubular Structures for Progressive Buckling Using Compliant Mechanism Approach2013-01-065804/08/2013
This investigation introduces a methodology to design dynamically crushed thin-walled tubular structures for crashworthiness applications. Due to their low cost, high-energy absorption efficiency, and capacity to withstand long strokes, thin-walled tubular structures are extensively used in the automotive industry. Tubular structures subjected to impact loading may undergo three modes of deformation: progressive crushing/buckling, dynamic plastic buckling, and global bending or Euler-type buckling. Of these, progressive buckling is the most desirable mode of collapse because it leads to a desirable deformation characteristic, low peak reaction force, and higher energy absorption efficiency. Progressive buckling is generally observed under pure axial loading; however, during an actual crash event, tubular structures are often subjected to oblique impact loads in which Euler-type buckling is the dominating mode of deformation. This undesired behavior severely reduces the energy
Shinde, Satyajeet, Bandi, Punit, Detwiler, Duane, Tovar, Andres
Idealized Vehicle Crash Test Pulses for Advanced Batteries2013-01-076404/08/2013
This paper reports a study undertaken by the Crash Safety Working Group (CSWG) of the United States Council for Automotive Research (USCAR) to determine generic acceleration pulses for testing and evaluating advanced batteries subjected to inertial loading for application in electric passenger vehicles. These pulses were based on characterizing vehicle acceleration time histories from standard laboratory vehicle crash tests. Crash tested passenger vehicles in the United States vehicle fleet of the model years 2005-2009 were used in this study. Crash test data, in terms of acceleration time histories, were collected from various crash modes conducted by the National Highway Traffic Safety Administration (NHTSA) during their New Car Assessment Program (NCAP) and Federal Motor Vehicle Safety Standards (FMVSS) evaluations, and the Insurance Institute for Highway Safety (IIHS). These crash modes included: Frontal rigid flat barrier test at 35 mph (NHTSA NCAP), 40% offset frontal deformable
Barbat, Saeed, Mehall, Mark, Nayak, Raviraj, Nusholtz, Guy S., Olds, Natalie M., Shi, Yibing, Stanko, William, Wang, Jenne-Tai, Weerappuli, Para, Xu, Lan, Yalamanchili, Krishnarao Venkata
Investigation of Crashworthiness of Structural Composite Components in Frontal and Side NCAP Tests2013-01-065004/08/2013
This paper investigates the crashworthiness of structural composite components in frontal and side crash tests. In addition, the safety benefits of composites applications in future lighter vehicles are studied. The methodology of the research includes two steps: (1) developing a light-weight vehicle based on a current finite element (FE) vehicle using advanced plastics and composites, and (2) evaluating the crashworthiness of the light-weighted vehicle by frontal and side New Car Assessment Program (NCAP) test simulations. An FE model of a 2007 Chevrolet Silverado, which is a body-on-frame pickup truck, was selected as the baseline vehicle for light-weighting. By light-weighting components in the Silverado, the vehicle weight was reduced 19%. As a result, the content of plastics and composite in the light-weighted vehicle was 23.6% of the total weight of the light-weight vehicle. Light-weighted composite structural components include bumpers, front-end module, fenders, pillar
Park, Chung-Kyu, Kan, Cing-Dao (Steve), Hollowell, William Thomas
Influence of Welded Joints on the Crashworthiness Response of Hybrid Structural Elements2013-01-075504/08/2013
In this paper, the effect of welded joints on the crashworthiness response of a hybrid system is presented. This hybrid system consists of a steel enclosure filled with different core materials: carbon-fiber reinforced polymer, glass-fiber reinforced polyamide, polyethylene terephthalate foam and natural cork conglomerate. The metallic enclosure is a cold-formed tube which has to be spot-welded to assemble the final design. The focus is set on the assessment of the effect of the pattern and the number of spot welds on the crashworthiness results in terms of absorbed energy. Results show that variations in the number or the geometric distribution of the spot welds have a direct and noticeable effect on the final amount of energy that the part can dissipate. This is due to the crushing mechanism of the metallic column which is highly sensitive to the way that cold-formed sections are joined. From these results, several design recommendations can be proposed for the design of hybrid
Costas, Miguel, Diaz, Jacobo, Romera, Luis Esteban, Hernandez, Santiago, Ledo, Raquel
Selection of Optimal Design Parameters to Achieve Improved Occupant Performance in Frontal Impacts2013-01-075604/08/2013
Crashworthiness enhancement of vehicle structures is a very challenging task during the early design development process. Major factors influencing occupant injury in frontal impact are vehicle front crush space, crash pulse severity, restraint properties and occupant packaging space. This paper establishes a methodology to define suitable criterion that will guide the designers to select the optimal values of the above mentioned parameters during the early phase of the vehicle development. The usage of lumped mass models, pulse characterization techniques were explored to validate the results. Efficient crash energy management, the concepts of ride down and restraint efficiency parameters were also discussed in the paper.
Peddi, Sairama Narayana
Fuel System Crashworthiness for Recreational Off-Highway Vehicles2012-01-098804/16/2012
Recreational Off-Highway Vehicles (ROVs) are a distinct class of vehicles defined by an American National Standard (ANSI). The vehicles are intended primarily for recreational use and may have secondary general utility applications. The American National Standard (ANSI) for Recreational Off-Highway Vehicles addresses minimum requirements for aspects of ROV equipment and configuration, but includes no discussion regarding the design or performance of ROV fuel systems. The purpose of this study was to: survey pre- and post-ANSI Standard designs of ROV fuel systems; examine fuel system design recommendations and requirements for other types of fueled motive equipment, including diverse types of recreational equipment; and describe the environment in which the ROV was intended and the environment in which it was legal for use. SAE Standards, Recommended Practices and Information Reports for diverse human-operated fueled motive equipment from personal watercraft to motorcycles revealed
Arndt, Mark William
Concepts for Mechanical Abuse Testing of High-Voltage Batteries2012-01-012404/16/2012
Currently lithium-batteries are the most promising electrical-energy storage technology in fully-electric and hybrid vehicles. A crashworthy battery-design is among the numerous challenges development of electric-vehicles has to face. Besides of safe normal operation, the battery-design shall provide marginal threat to human health and environment in case of mechanical damage. Numerous mechanical abuse-tests were performed to identify load limits and the battery's response to damage. Cost-efficient testing is provided by taking into account that the battery-system's response to abuse might already be observed at a lower integration-level, not requiring testing of the entire pack. The most feasible tests and configurations were compiled and discussed. Adaptions of and additions to existing requirements and test-procedures as defined in standards are pointed out. Critical conditions that can occur during and after testing set new requirements to labs and test-rigs. A ‘thermal runaway
Sinz, Wolfgang, Feist, Florian, Gstrein, Gregor, Gugler, Jürgen, Tomasch, Ernst, Breitfuss, Christoph, Luttenberger, Peter, Steffan, Hermann, Gollob, Peter, Hennige, Volker
An Application of Cluster Analysis to Dummy Injury Readings in a Frontal Crash2012-01-055604/16/2012
Public concern about the crashworthiness of vehicles has been continuously rising in recent years. Crashworthiness is evaluated under various crash configurations, including frontal collisions, in regulatory testing and in New Car Assessment Programs. Accordingly, vehicle manufacturers must deploy sophisticated product development strategies and redouble their engineering efforts in order to develop vehicles that satisfy the specified requirements for crashworthiness. Computer simulation is one effective approach to resolving this issue in that it provides a valuable tool for conducting multiple parameter studies and iterations in a short period of time. However, it is no easy task for CAE engineers to analyze the large volumes of calculation results obtained in frontal crash simulations and to understand the phenomena involved. One reason is that a great deal of time is needed to understand the many calculation results comprehensively, despite the fact that frontal crash phenomena are
Koizumi, Naoya, Ono, Masamoto, Natori, Sou, Araki, Toshihiro
Validation of Sled Tests for Far-Side Occupant Kinematics Using MADYMO2010-01-116004/12/2010
Far-side occupants are not addressed in current government regulations around the world even though they account for up to 40% of occupant HARM in side impact crashes. Consequently, there are very few crash tests with far-side dummies available to researchers. Sled tests are frequently used to replicate the dynamic conditions of a full-scale crash test in a controlled setting. However, in far-side crashes the complexity of the occupant kinematics is increased by the longer duration of the motion and by the increased rotation of the vehicle. The successful duplication of occupant motion in these crashes confirms that a sled test is an effective, cost-efficient means of testing and developing far-side occupant restraints or injury countermeasures. Previous work by these authors analyzed 9 crash modes that represent 44% of the total far-side occupant crash exposure and account for 56% of all MAIS3+ far-side injured occupants in the National Automotive Sampling System/Crashworthiness Data
Cuadrado, Joseph, Smyth, Brian, Smith, James, Digges, Kennerly
Frontal Crash Protection in Pre-1998 Vehicles versus 1998 and Later Vehicles2010-01-014204/12/2010
This investigation addresses and evaluates: (1) belted drivers in frontal crashes; (2) crashes divided into low, medium, and high severity; (3) air-bag-equipped passenger vehicles separated into either model years 1985 - 1997 (with airbags) or model years 1998 - 2008; (4) rate of Harm as a function of crash severity and vehicle model year; and (5) injury patterns associated with injured body regions and the involved physical components, by vehicle model year. Comparisons are made between the injury patterns related to drivers seated in vehicles manufactured before 1998 and those manufactured 1998 or later. The purpose of this comparative analysis is to establish how driver injury patterns may have changed as a result of the introduction of more recent safety belt technology, advanced airbags, or structural changes. More recent years of NASS/CDS have meant that additional 1998+ model year vehicles were available for analysis, and there were almost equal number of frontal crashes
Scullion, Paul, Morgan, Richard M., Digges, Kennerly H., Kan, Cing-Dao
Ambulance Vehicle Crashworthiness and Passive Safety Design: A Comparative Evaluation2008-01-269510/07/2008
Ambulances are largely exempt from crashworthiness and occupant protection passive safety design standards in the USA, and have a poor road safety record. This comparative evaluation of USA ‘concept safety’ ambulances and a standard Australian ambulance is based on basic principles of crashworthiness and available crash test data. There are features of USA ambulance design that are not within known principles and technical aspects of crashworthiness and safety design, and include some predictable serious occupant protection hazards. The USA ambulance industry should recognize and apply crashworthiness and occupant protection principles to reduce current system failures for this fleet of essential service vehicles.
Levick, Nadine, Grzebieta, Raphael
Rollover Dynamics: An Exploration of the Fundamentals2008-01-017204/14/2008
Research focusing on automotive rollovers has garnered a great deal of attention in recent years. Substantial effort has been directed toward the evaluation of rollover resistance. Issues related to crashworthiness, such as roof strength and restraint performance, have also received a great deal of attention. Much less research effort has been directed toward a more detailed study of the rollover dynamics from point-of-trip to point-of-rest. The reconstruction of rollover crashes often requires a thorough examination of the events taking place between point-of-trip and point-of-rest. Increasing demands are placed on reconstructionists to provide greater levels of detail regarding the roll sequence. Examples include, but are not limited to, roll rates at the quarter-roll level, CG trajectory (horizontal and vertical), roll angle at impact, and ground contact velocity. Often the detail that can be provided in a rollover reconstruction is limited by a lack of physical evidence. However
Carter, Jarrod W., Luepke, Peter, Henry, Kevin C., Germane, Geoff J., Smith, James W.
A Frontal Impact Taxonomy for USA Field Data2008-01-052604/14/2008
An eight-group taxonomy was created to classify real-world frontal crashes from the Crashworthiness Data System (CDS) component of the National Automotive Sampling System (NASS). Three steps were taken to develop the taxonomy: (1) frontal-impact towaway crashes were identified by examining 1985-2005 model year light passenger vehicles with Collision Deformation Classification (CDC) data from the 1995-2005 calendar years of NASS; (2) case reviews, engineering judgments, and categorization assessments were conducted on these data to produce the eight-group taxonomy; and (3) two subsets of the NASS dataset were analyzed to assess the consistency of the resulting taxonomic-group frequencies. “Full-engagement” and “Offset” crashes were the most frequent crash types, each contributing approximately 33% to the total. The group identified as “D, Y, Z No-Rail” was the most over-represented crash type for vehicles with at least one seriously-injured occupant. However, that group represented only
Sullivan, Kaye, Henry, Scott, Laituri, Tony R.
Automotive Engineering International 2006-03-01AUTOMAR0603/01/2006
Hybridization gathers momentum Gasoline-electric hybrid vehicles continue to grow in popularity, with many incremental advances coming from Japanese OEMs and suppliers. Broadening telematics' reach More infotainment options pose many challenges. Nano goes macro While nanotechnology deals with materials at the minutest of levels, the auto industry has grand plans for its use in a multitude of areas. The transformation of testing Software is helping physical tests produce more accurate results more efficiently. Advancing crashworthiness simulation BMW worked closely with software developers at ABAQUS to produce a customized solution for virtual product development. Low-cost latitude Contrary to popular belief, 'low cost' does not automatically mean 'Chinese.' SAE 2006 World Congress Preview Toyota and host company BMW join Ford, General Motors, and Chrysler for a record number of OEMs on the floor at the April 3-6 event.
SAE Occupant Protection & CrashworthinessOPDEMO03/08/2005
Thank you for your interest in the SAE Occupant Protection & Crashworthiness Technology Collection. This demo gives you an overview of the functionality of the product, illustrating the search interaction and the navigational features. You'll want to try a few searches so you can become familiar with the look and feel of the product and the navigational tools it offers. Please note: this demo does NOT provide you with the content of the product. It contains only one document to show you how you can link from the document summary to the full-text PDF. For information on the content of the product, please see the SAE website. You will be asked to login to the SAE Website before accessing the demo. This will require you to register as a new user if you do not already have an SAE Website account. Click on the following link to access the demo: If you have any questions, please e-mail CustomerService@sae.org or call 1-724-776-4970. You may also be interested in: Accident Reconstruction
Important Considerations in the Development of a Test to Promote Stable Bumper Engagement in Low-Speed Crashes2004-01-131903/08/2004
Nolan, Joseph M., Brumbelow, Matthew, Zuby, David S., Avery, Matthew
Structural Reinforcements for Automotive Applications2003-01-033003/03/2003
The use of adhesively bonded localized reinforcements is a relatively new concept in the automotive industry. Although use of this reinforcement method is in its early stages, these reinforcements are now used for a variety of applications in the automotive industry for improvements in crash worthiness, fatigue resistance, and NVH characteristics. This approach can provide relatively fast, easy, non-intrusive, and cost effective solutions for OEM's when compared to traditional reinforcement methods. Also, overall weight can be reduced simultaneously since the reinforcement is placed only where needed instead of filling an entire section with foam or changing the metal thickness along an entire body member. Materials and concepts have been developed that can be used to improve the structural stiffness and the resulting NVH performance of the vehicle. This paper will discuss the use of localized reinforcements including materials, applications, and potential uses and benefits.
Carlson, David, Czaplicki, Michael, Riley, Jon
PROGRESS OF PASSIVE SAFETY IN CAR-TO-CAR FRONTAL COLLISIONS: RESULTS FROM REAL-LIFE CRASH ANALYSES AND FROM CRASH TESTS2001-06-019806/04/2001
The progress of passive safety in car-to-car frontal collisions can be seen very clearly from the results of crash tests with old and new car models. The published federal accident statistics show an overall effort in passive safety, which is obvious by decreasing figures of killed and severely injured car occupants per year on German roads. But it is not possible to exclusively focus on car crashes with frontal collisions because the characteristics investigated in official statistics are not detailed enough. Therefore additional in-depth studies are necessary. The paper shows results of car-to-car and car-to-barrier frontal impacts for old and new car models. Some results of evaluations using the federal German statistics show historical trends in a more general view. Interdisciplinary real-life crash studies are focused on car-to-car frontal collisions. Results of connecting assessments using vehicle deformation index (VDI), energy equivalent speed (EES), velocity change (delta-v
Berg, F. Alexander, Rücker, Peter, Niewöhner, Walter, Miltner, Erich, Stein, Kirsten Marion
Evaluation of the effect of air bags in multi-year light truck NCAP tests2001-06-009506/04/2001
The New Car Assessment Program (NCAP) has evaluated the crashworthiness of numerous vehicles since 1979. Each year selected models were frontally crashed at 35 mph into a fixed barrier. Due to increased interest by the public in vehicle safety as part of their car-buying decisions, NHTSA has recently undertaken an expanded program of consumer information on vehicle safety issues. As part of this program, an analysis was performed to determine the effectiveness of light-truck driver air bags to reduce the risk of severe injury as measured by the head and chest injury responses of selected NCAP tests. The light trucks tested most frequently were analyzed to obtain reliable estimates of air bag effectiveness. The vehicles were tested with all the restraints available on that model, which in the case of the early years were safety belts, and in the latter years were a combination of safety belts and air bags. Analysis of NCAP data for multi-tested vehicle models for the period 1979 through
Berkowitz, Alan
Improved safety for drivers and couriers of coaches2001-06-013806/04/2001
According to general accidents statistics a coach is the safest means of transportation with respect to fatalities per billion traveler kilometers. Reasons for this include the existing regulations related to coach safety and the self-regulation of the coach building industry. Most passive safety standards are, however, more related to the safety of the passengers and less to the safety of driver and courier. Their typical position at the front of the coach and the fact that most heavy structural parts of the coach are behind their position in the coach, make the driver and courier vulnerable in case of a frontal collision. The injury risk in specific frontal collisions can be reduced by applying crash technology within the front structure of the coach. By redesign and reorganizing the structure and the packaging underneath the driver and courier, the kinetic energy developed in a typical coach-to- trailerback collision can be absorbed whilst maintaining a survival space for driver and
de Coo, Peter, Hazelebach, Rene, van Oorschot, Eric, Wessels, Jaap
Old car crash test program2001-06-018006/04/2001
Older vehicles do not have to meet the same safety standards that modern cars are required to meet. This paper presents some observations about the structural and safety performance of older vehicles in the frontal offset crash test conducted by the Australian New Car Assessment Program (ANCAP), the Insurance Institute for Highway Safety (IIHS) and EuroNCAP for consumer information. Some comparisons of the safety performance between new and old vehicles in offset crash tests are made. The test results were analyzed to determine the various factors that contribute making a vehicle crashworthy. The newer vehicles generally scored better than the older vehicles. The results inform consumers about differences in safety features between new and old vehicles.
Haley, Jack, Bonney, Vanessa
Comparative analysis of several vehicle safety rating systems2001-06-003006/04/2001
The paper examines the application of six vehicle safety rating systems to a common crash database, for the purpose of making a comparison of the rating results produced by each system and to develop an understanding of the differences which emerge. The rating results are compared based on rank order of crashworthiness of vehicle models, and relationships between each pair of results. Finally, the results with their respective confidence limits are used to classify each vehicle model as having inferior, not defined or superior crashworthiness, and the classification is used to compare the relative discrimination of the methods.
Cameron, Max, Narayan, Sanjeev, Newstead, Stuart, Ernvall, Timo, Laine, Vesa, Langwieder, Klaus
Composite-Fuselage Concept for Greater CrashworthinessTBMG-3003111/01/1999
A continuing program of research is directed toward the development of crashworthy composite-material fuselages for small aircraft. These fuselages are required not only to withstand flight loads and exhibit the required aerodynamic characteristics, but also to protect occupants during crashes more effectively than do conventional fuselages. The design goal for protection against crashes is to limit loads applied to occupants to survivable levels in vertical impacts onto rigid surfaces at a speed of 31 ft/s (9.4 m/s). This vertical impact speed exceeds that specified in current regulatory criteria for small aircraft, but it is a realistic, potentially survivable, impact velocity that has been observed in crashes and in crash tests performed at Langley Research Center.
Car Crash Simulation Studies using Explicit Nonlinear Finite Element Analysis99005701/13/1999
The paper describes simulation of frontal barrier impact of a car body shell structure for crashworthiness analysis using non linear explicit finite element package LS-DYNA3D. Predicted overall collapse modes of different structural component viz.apron, side rails etc. are in a good agreement with published results and also to some extent with experimental results. In this paper crash analysis of above car structure with crash guard is simulated using LS-DYNA3D and comparative analysis of crash behaviour of car structure in the presence of crashguard is shown to indicate its possible role on crash behaviour of a vehicle.
Gadekar, G. B., Athavale, Swati M., Sajanpawar, P. R.
Method to Predict the Energy Absorption Rate Characteristics for a Structural Member98238809/29/1998
The rate of energy absorption during the plastic deformation of structural components is an important factor in the design of automotive safety systems such as chassis crumple zones. This paper describes a design tool for predicting energy absorption characteristics. The tool was based on measurements of the energy absorption rates of twenty-three selected materials subjected to three impact energy conditions. A well-established finite element code, LS-DYNA3D, was used with a mesh representing a hollow column of square cross-section to establish a database of energy absorption characteristics. A mathematical model representing the energy absorption rates was determined and the material properties most influencing the energy absorption rates were identified. A parabolic model best represented the energy absorption charactersitics. The regression coefficients for the model were determined for all tested materials under the selected test conditions. In this study, the most influential
Anderson, Beth, Ziejewski, Mariusz, Goettler, Hans
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