{"title":"Intelligent Hydraulic Bumper for Frontal Collision Mitigation","authors":"Saad A. W. Jawad","doi":"10.1115/imece1996-1023","DOIUrl":"https://doi.org/10.1115/imece1996-1023","url":null,"abstract":"\u0000 A proposal for collision mitigation is investigated in this paper. Two intelligently controlled hvdraulic cylinders is proposed to be extended prior to collision and absorb impact energy upon engagement with the other body. Feasibility and performance of collision mitigation were investigated with a simulation of the collision dynamics. Two phases of control were considered; pre-collision control and collision control. Various collision scenarios have been studied with view of predicting collision and proposing a pre-collision control strategy for activating the proposed hydraulic bumper. A learning digital computer pre-collision control is proposed.\u0000 For the purpose of this research a 0.5 m stroke hydraulic cylinders is used to act as an effective extension of the crash zone. A specially adapted fast response hydraulic flow control valve is proposed with certain collision control law. The collision control law aims at controlling the collision force at a given level corresponding to occupants acceleration not exceeding 20g. Simulation results revealed a maximum level of 15g deceleration could be achieved in a 30 mph collision.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122371300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparison of Different Material Models in Simulating Compression and Energy Absorption of Bumper Foam During Low Speed Impact","authors":"Ping Chen, Bhimaraddi Alavandi, N. Saha","doi":"10.1115/imece1996-1022","DOIUrl":"https://doi.org/10.1115/imece1996-1022","url":null,"abstract":"\u0000 In this paper an analytical modeling of foam material using four different formulations is considered. Four material models considered here (MATERIAL LAWS 10, 21, 28 and 35) are available in RADIOSS (commercial non-linear finite element analysis code). All four models are used in simulating the deformation of structures consisting of foam components. Static compression test data, on foam cube samples of different densities, are first validated to arrive at the material parameters required as input to RADIOSS. Then, an application of foam material in an energy absorbing front bumper structure is studied. Comparison of these material models in low speed impact testing is carried out. Based upon the experience gained on material modeling of foam. Material Law 10 or 28 (preferably 28) is recommended to simulate low speed impact testing.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134097899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Predicting Vehicle Crash Performance in Offset Barrier Impact","authors":"B. Fileta, X. Liu","doi":"10.1115/imece1996-1011","DOIUrl":"https://doi.org/10.1115/imece1996-1011","url":null,"abstract":"\u0000 This paper describes experimental and analytical techniques developed to alter a full barrier, one-dimension. lumped mass-spring model to a model which can be used to calculate the vehicle response in an offset rigid barrier impact. The changes to the full barrier model were based on significant findings from the comparative experimental investigation of the vehicle behavior in offset and full rigid barrier crashes. The techniques used to analyze the data in this experimental investigation are discussed. These techniques proved to be very effective in developing correlation factors between the two test types. Furthermore, methods of applying the experimental factors to generate new spring, mass, and contact data for modeling and crash simulation of the offset impact are presented. Finally, the paper discusses the correlation between the analytical results of the modified model and the crash test results.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131896064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Validation of a Non-Linear Finite Element Vehicle Model Using Multiple Impact Data","authors":"A. Zaouk, N. Bedewi, C. Kan, D. Marzougui, Fhwa","doi":"10.1115/imece1996-1017","DOIUrl":"https://doi.org/10.1115/imece1996-1017","url":null,"abstract":"\u0000 A detailed multi-purpose finite element model of a 1994 Chevrolet C-1500 pick-up truck was developed at the FHWA/NHTSA National Crash Analysis Center. The model is the first of its kind developed specifically to address vehicle safety issues, including front and side performance, as well as road side hardware design. The former application typically involves large regional deformation with impact durations of no more than 150 msec. The latter encompasses damage along a larger portion of the vehicle, and due to longer interaction time between the vehicle and impacted device coupled with the need to observe post impact dynamics, requires simulations that could last as long as 1 second.\u0000 This paper describes the results of a non-linear finite element computer simulation using this model for frontal full barrier and median highway barrier impacts. These simulations are conducted in support of research studies undergoing at the National Highway Traffic Safety Administration (NHTSA) and the Federal Highway Administration (FHWA) to investigate vehicle compatibility, new offset barrier tests, and highway/vehicle safety issues. Full scale vehicle crash tests conducted by NHTSA and FHWA are used for evaluation of the performance of the model. Two tests are compared, a frontal impact with a full rigid wall and a corner impact to a 42-inch Vertical Concrete Median. The comparisons between tests and simulations in terms of overall impact deformation, component failure modes, velocity and acceleration at various locations in the vehicle are presented. Modeling issues including element size, connectivity, and slide line interface of different parts are discussed. In addition, some simulation related hardware and software issues are addressed. The results clearly indicate the model to be consistent with the full scale tests. Additional simulations need to be performed to fully evaluate and validate the model.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"497 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127044572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Linear Visco-Elastic Material Model for Headform Skin With Applications to Interior Head Impact Protection","authors":"M. Faruque, N. Liu, C. Chou","doi":"10.1115/imece1996-1021","DOIUrl":"https://doi.org/10.1115/imece1996-1021","url":null,"abstract":"\u0000 Vinyl rubber dummy skin used in the deformable featureless head form exhibits rate sensitivity. This rate sensitivity seems to play a significant role in the interior head impact evaluation. In order to characterize the rate dependency of dummy skin, a linear visco-elastic material law is developed in FCRASH. To validate this model, a number of hcadform drop tests and interior head impact events are simulated using FCRASH and results are compared with the test data. Evidently excellent agreement is achieved between the analyses and the test data.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126845346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Gentry, L. Bank, Jiansheng Yin, J. D. Lamtenzan
{"title":"Damage Evolution and Progressive Failure in Composite Material Highway Guardrails","authors":"T. Gentry, L. Bank, Jiansheng Yin, J. D. Lamtenzan","doi":"10.1115/imece1996-1016","DOIUrl":"https://doi.org/10.1115/imece1996-1016","url":null,"abstract":"\u0000 The evolution of damage and the progressive failure of prototype highway guardrails, constructed of thermoset plastic /E-glass composite materials, is described. The composite material guardrails are being studied as potential replacements for conventional steel w-beam guardrails. The objective of this phase of the study was to investigate progressive failure of composite cross-sections as a means of dissipating energy in the guardrail when subjected to a vehicular impact. The prototype rails were connected to standard steel blockouts and tested quasi-statically under displacement control. The blockouts were designed to allow local rotation of the blockouts and large deflection of the guardrail sections so as to develop a tension field in the rail following the initial “local damage phase.” The results of the static tests on the composite rails were compared with those of a standard steel w-beam tested in the same fixture. From the quasi-static tests the evolution of the local damage and the progressive failure in the composite prototype rails could be observed. Observed changes in failure modes at different load levels could be correlated with discontinuities in the load-deformation data obtained during the testing. A study of the energy absorbed during the initial flexural damage phase (prior to the tension field developing in the rail) revealed the relative contribution of this phase to the overall energy absorbed during the progressive failure of the rail. From this preliminary study it appears that composite material guardrails may be able to dissipate more energy in the initial flexural phase than conventional steel w-beams.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"48 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128994599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of Automotive Body Structure for Roof Crush","authors":"H. Mahmood, M. Baccouche","doi":"10.1115/imece1996-1012","DOIUrl":"https://doi.org/10.1115/imece1996-1012","url":null,"abstract":"\u0000 This paper investigates the parameters that influence the design and analysis of automotive structures subject to roof crush loading. Influence of components such as roof bows, A-pillars, B-pillars, roof side rails, windshield header, and windshield glass on the load carrying capacity of the green house structure is discussed. Several analysis of the roof model were carried out to simulate the effect of roof bows, windshield glass, windshield header, and roof side rail span. The results of this analysis are discussed in terms of components contribution to the strength and stability of the greenhouse structure. The mode of collapse of the 3D roof structure is analyzed and the formulation of the plastic hinges and maximum collapse moment is discussed.\u0000 Results from a non-linear finite beam element system code are presented in this paper. Axial and bending strengths, sequences of failure, and modes of collapse from this code are discussed at both the component and system level. Also presented in this paper is a summary of engineering guidelines and recommendations for designing roof structure components to carry roof crush load.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128959746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamic Analysis of the Lightweight Mission Specialist Seats for the Space Shuttle Orbiter","authors":"Wayne A. Jermstad","doi":"10.1115/imece1996-1013","DOIUrl":"https://doi.org/10.1115/imece1996-1013","url":null,"abstract":"\u0000 The Orbiter Lightweight Seat - Mission Specialist (LWS-MS) is designed to replace the existing mission specialist seats in the space shuttle orbiter. The goal of the LWS-MS project is to reduce the weight of each seat by 50%, while increasing crashworthiness. The development of typical aircraft seats relies heavily on dynamic crash testing. The LWS-MS team at the NASA Johnson Space Center (JSC) reduced the amount of dynamic testing required by performing dynamic analysis of the seat and occupant.\u0000 The analysis uses the Dynamic Analysis and Design Software (DADS) package by Computer Aided Design Software, Inc. Custom code was added to model the seat restraint system, and to model contact between the occupant and the seat. The occupant is modeled as a group of rigid bodies. The seat is represented by its mass and stiffness matrices and by its normal modes. The DADS model shows good correlation with test data for both low and high level input tests.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133499912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Mahmood, Donald Wheatley, H. H. El-Hor, Hassen Hammoud
{"title":"Offset Crush Analysis and its Applications","authors":"H. Mahmood, Donald Wheatley, H. H. El-Hor, Hassen Hammoud","doi":"10.1115/imece1996-1019","DOIUrl":"https://doi.org/10.1115/imece1996-1019","url":null,"abstract":"\u0000 Until recently, frontal crash analysis and tests were performed to predict the performance and behavior of cars to meet full frontal crash safety requirements. Little has been done so far to control the energy absorption during an offset frontal crash. This topic has become a very interesting and challenging issue since it will be included in the federal regulations in the coming years.\u0000 In offset crash, the load is applied to one side of the front end, leaving the other side partially unloaded. In light of this situation, cross-members have to be carefully designed in order to absorb and safely transmit part of the offset crash load to the opposite side.\u0000 This paper will describe the theoretical performance of the front structure under an offset crash and at the same time identify all related parameters that influence this behavior. A computerized analysis of the single, full and offset crash will be performed and results and comparisons will be tabulated and graphed.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130020359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Study of Countermeasures for Upper Interior Head Impact","authors":"A. Deb, S. M. Calso, N. Saha","doi":"10.1115/imece1996-1020","DOIUrl":"https://doi.org/10.1115/imece1996-1020","url":null,"abstract":"\u0000 Impact-resistant trim covers on vehicle pillars can aid in reducing HIC(d) (Head Injury Criterion, dummy) during upper interior headform impact. Reductions in HIC(d) also can be aided by an air-gap (i.e. packaging space) between trim and a typical pillar inner panel usually made of steel. For a given packaging space, further lowering of HIC(d) is possible using additional countermeasures such as crushable foam and integrally molded trim ribs which are discussed in this paper. The potential effectiveness of foams of different strengths and integrated ribs for trim is assessed via nonlinear finite element modeling and transient dynamic analysis using a commercial package (RADIOSS). Some comparisons between analysis and test results are also presented.","PeriodicalId":102994,"journal":{"name":"Crashworthiness and Occupant Protection in Transportation Systems","volume":"37 23","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132064492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}