Browse Topic: Rollover protective structures

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A Simplified Analytical/Experimental Method for Evaluating Large Buses and Motor Coaches for Rollover Protection2018-01-50338/27/2018
This paper discusses a simplified analytical/experimental method for evaluating and designing large buses and motor coaches for rollover protection. The proposed method makes use of the work-energy principle in analyzing the energy-absorbing capacity of the roof and sidewall structure of the vehicle. The basic structural unit is treated as a nonlinear, elastoplastic, 4-bar linkage, with the links connected at hinge points. During rollover, the deformation of the structure is focused at these hinge points and energy absorption is achieved through plastic bending and rotation of the hinge material. The proposed method allows the evaluation and design of these plastic hinges to achieve the energy-absorbing requirements for the vehicle. This paper demonstrates the proposed methodology by evaluating an exemplar large bus design against the European ECE-R.66 rollover design standard. This same vehicle was similarly evaluated in a referenced study, using the finite element analysis (FEA) method. The objective of both studies was to determine a minimum weight solution for the vehicle structure. The minimum weight solution must satisfy both the minimum energy absorption requirements and the structural deformation limitations placed on the design by the ECE-R.66 standard. Both a baseline design and an optimized (minimum weight) design were evaluated in this study. The baseline design served as a reference point in determining the weight-saving potential for the vehicle. The FEA results show a weight-saving potential of 78 kg (172 lb) while the simplified, 4-bar linkage model gives a slightly heavier design with a weight-saving potential of 34 kg (77 lb), indicating that the proposed method of analysis is slightly conservative compared to the FEA method.
Pauls, Lonney S.
Limbs Related Handicap Drivable Non-Commercial Electric Shuttle Vehicle2018-28-00557/9/2018
The main objectives of this work are to develop an Electric Vehicle to empower physically challenged drivers to some extent and women motorist. The vehicle was designed to be driven by people with orthopaedic limps related problem by using Autodesk Inventor software. Many features were provided to support the physically challenged person such as a ramp for the driver to board the vehicle and steering, acceleration and braking control was also provided for a single hand to manoeuvre the car. The vehicle has the capacity to seat up to six passengers and is propelled with 1200 watts (BLDC) motor which was aided by four 12 V and 100 Amps DC battery. The car exhibited a mileage of 72 kilometres per complete charge on trial run with the driver alone riding the vehicle. This work is mainly dedicated to movement disabled in our society.
Elsen, Renold, Kaliyaperumal, Dhamodaran
Tolerances Copper and Copper Alloy Sheet, Strip, and PlateAMS2222K (Historical)11/3/2017
This specification covers established inch/pound manufacturing tolerances applicable to copper and copper alloy sheet, strip, and plate ordered to inch/pound dimensions. These tolerances apply to all conditions, unless otherwise noted.
AMS D Nonferrous Alloys Committee
Kid: A Telemedicine Solution for Retinopathy of PrematurityTBMG-2784411/1/2017
Retinopathy of prematurity (ROP) is a disease that affects premature infants. It is the leading cause of childhood blindness. Although effective treatments exist, many infants are still at-risk due to the small window of time for detection. The current standard of care consists of in-person, manual screening by a pediatric ophthalmologist. Unfortunately, the number of infants in need of screening far surpasses the availability of specifically trained ophthalmologists. Consequently, fewer than 30 percent of neonatal intensive care units (NICUs) worldwide have fully compliant ROP screening programs.
Minimum Performance Criteria for Operator Front Protective Structure (OFPS) for Certain EquipmentJ2267_201710 (Historical)10/26/2017
This SAE standard applies to all forestry machines exposed to the hazard of objects penetrating the front of the operator station (other than the roof). This would include:
MTC4, Forestry and Logging Equipment
Static Analysis on a Roll Cage Frame for an Off-Road Vehicle2017-01-12993/28/2017
The objective of this research is to design and analyze a roll cage structure for an off-road vehicle that was used for SAE Baja competition by UNLV SAE Baja team. Baja SAE is an intercollegiate competition to design, fabricate, and race a small, single passenger, off-road vehicle powered by a 10 HP Briggs Stratton 4-Stroke gasoline engine. Since the off-road vehicle is powered by a small capacity engine, the weight of the structure is very critical and must be optimized to improve the performance of the vehicle. In an effort to optimize the structure, a finite element analysis (FEA) was performed and the effects of stress and deformation were studied for a linear static frontal impact analysis on roll cage structure. The frame was further modified for structural rigidity. Additional strengthening gussets were added at the locations of high stresses to reduce the stress concentration. Further analysis was carried out to study the influence of other auxiliary structures attached to the frame such as the engine mount, transmission and other components of the vehicle. The design of the structure was considered safe when the Von-Mises stresses were less than the yield strength of the material and the deflections of the structural members were favorable enough for the safety of the driver.
Noorbhasha, Nagurbabu, O'Toole, Brendan J.
Overhead Protection for Agricultural Tractors - Test Procedures and Performance RequirementsJ167_201701 (Historical)1/6/2017
This SAE Standard applies to an overhead cover installed on a protective frame or enclosure conforming to SAE J2194 or alternately SAE J1194 and the following additional requirement of a drop test to verify the effectiveness of the overhead cover in protecting the operator from falling objects. The test procedures and performance requirements outlined in this document are based on currently available engineering data.
OPTC4, Protective Structures
Minimum Performance Criteria for Falling Object Guards for ExcavatorsJ1356_201303 (Historical)3/28/2013
This SAE Recommended Practice applies only to excavators, as defined in SAE J/ISO 6165, working above ground, near an excavated or free standing bank or mine face which is higher than the top of the cab, or in demolition applications of free standing buildings or objects higher than the top of the cab.
OPTC4, Protective Structures
Nomenclature - Hydraulic BackhoesJ326_201211 (Historical)11/1/2012
This SAE Standard includes hydraulic backhoes which have no more than 190 degrees of rotational swing, and are mounted on wheel tractors and crawler tractors. Illustrations used are not intended to include all existing commercial machines or to be exact descriptions of any particular machine. The illustrations have been chosen to describe the principles to be used in applying this standard.
MTC1, Earthmoving Machinery
DOE for Non Linear Structural Analysis of ROPS (Rollover Protective Structure)2012-01-19029/24/2012
Rollover Protective Structures (ROPSs) are used in off-highway vehicles to protect operator in case of accidents involving overturning of vehicle. The role of a ROPS is to absorb the energy of Rollover without violating the protected operator zone. The performance of a ROPS is determined by its ability to absorb energy under prescribed loading conditions. The performance depends upon design parameters, such as tube thicknesses, material grades, ROPS tube cross-sections, etc., that define the structure. In this paper, we describe a method that uses Design of Experiments (DOE) to determine the correlation between the performance of a ROPS for a small tractor and its critical design parameters. The correlation results are discussed for two types of loading conditions, namely “front push loading” and “side push loading”. The correlation obtained is further used to identify the optimal design parameters for maximum energy absorption under constraints on allowable deflections.
Malik, Manish, Kshirsagar, Sandeep, Barve, Sachin
Specification Definitions - Hydraulic BackhoesJ49_201207 (Historical)7/16/2012
This standard applies to hydraulic backhoes which have no more than 190 degrees of rotational swing, and are mounted on wheel tractors and crawler tractors.
MTC1, Earthmoving Machinery
Operator Protection for General - Purpose Industrial MachinesJ1042_201206 (Current)6/29/2012
This SAE Standard applies to General-Purpose Industrial Machines described in Category 2 of SAE J1116, but excludes skid steer loaders (covered by SAE J1388). Protection for the operator of an attachment (for example, a backhoe) is excluded from the scope of this document.
OPTC1, Personnel Protection (General)
Biomechanics of Occupant Responses during Recreational Off-Highway Vehicle (ROV) Riding and 90-degree Tip-overs2012-01-00964/16/2012
Recently, side-by-side Recreational Off-Highway Vehicles (ROVs) have brought elements of the on-road vehicle occupant environment to the off-road trail-riding world. In general, ROV occupant protection during normal operation and in accident scenarios is provided predominately by a roll cage, seatbelts, contoured seats with seat backs, handholds, and other components. Typical occupant responses include both passive (inertial) and active (muscular) components. The objective of the current study was to evaluate and quantify these passive and active occupant responses during belted operation of an ROV on a closed course, as well as during 90-degree tip-over events. Passive occupant responses were evaluated using anthropomorphic test devices (ATDs) in 90-degree tip-overs simulated on a deceleration sled. Active occupant responses were evaluated using instrumented vehicles and volunteer occupants, wherein vehicle dynamics and gross occupant kinematics, muscle activity, occupant-to-vehicle pressure distributions and forces were quantified during riding on a closed course and during 90-degree tip-overs in a roll-spit fixture. For comparison, each test subject also performed a series of common physical activities while instrumented. Results indicated that the seatbelt was a critical component to the occupant protection system and that belted occupants were passively maintained within the occupant compartment during 90-degree tip-over events. Results also demonstrated that the active responses of the occupants further contributed to occupant stability and correlated significantly with the vehicle's lateral acceleration. Changes in patterns of muscle activation occurred approximate with the vehicle's change in turn direction and indicated a clear push-pull strategy of the occupant during left and right turns, respectively. Roll-spit testing demonstrated that the majority of lateral restraint was provided by the bucket seat, wherein modest lap belt forces constrained the pelvis within the seat contour and facilitated the generation of lateral contact forces. Forces exerted by occupants' extremities on the vehicle during a 90-degree tip-over were comparable to, or less than, the forces resulting from common physical activities.
Newberry, William, Carhart, Michael, Larson, Robert, Bridges, Amanda, Fowler, Graeme
Benefits and Methodology for Dimensioning a Vehicle Using a 3D Scanner for Accident Reconstruction Purposes2012-01-06174/16/2012
In the field of accident reconstruction, it is often important to measure the deformation of a vehicle (i.e. automobile, truck, motorcycle, etc.) after a crash has occurred. This data can be used for many purposes including energy calculations for speed loss, measuring roof or other structural deformation, analyzing seat or seat belt component positions, frame or unitized body structure deformation, and for estimating the actual post crash condition of a vehicle prior to the damage inflicted by the cutting and spreading tools used by emergency personnel. Traditionally, vehicle damage was measured using plumb bobs and tape measures or laser transits. However, these methods are not only time consuming but they also require a significant amount of upfront analysis to determine which points on the vehicle to measure at the inspection. In recent years, newer methods such as photogrammetry software and three dimensional scanners have come into play. Companies like FARO, Leica, Riegl, Trimble and Surphaser have developed these three dimensional laser scanners which can be used to efficiently document vehicle damage with millions of data points. The laser scanner equipment is simple to setup, collects data quickly and is accurate to a few millimeters. This paper describes the three dimensional scanning equipment and outlines a methodology of how to set it up at the vehicle inspection, how to process the voluminous data generated by the scanner, and then several case studies are presented showing how the data can be used in reconstructing crashes. The FARO Photon 80 scanner is used in examples.
Tandy, Donald F., Coleman, Clay, Colborn, Jason, Hoover, Todd, Bae, Jung
Aortic Mechanics in High-Speed Racing Crashes2012-01-01014/16/2012
Auto racing has been in vogue from the time automobiles were first built. With the dawn of modern cars came higher engine capacities; the speeds involved in these races and crashes increased as well. However, the advent of passive restraint systems such as the helmet, HANS (Head and Neck Support device), multi-point harness system, roll cage, side and frontal crush zones, racing seats, fire retardant suits, and soft-wall technology, have greatly improved the survivability of the drivers in high-speed racing crashes. Three left lateral crashes from Begeman and Melvin (2002), Case #LAS12, #IND14 and #99TX were used as inputs to the Wayne State Human Body Model (WSHBM) in a simulated racing buck. Twelve simulations with delta-v, six-point harness and shoulder pad as design variables were analyzed for the average maximum principal strain (AMPS) in the aorta. The average AMPS for the high-speed crashes were 0.1551±0.0172 while the average maximum pressure was 110.50±4.25 kPa. The average AMPS reported was significantly less than those reported in real-world accident reconstructions Belwadi et al., 2011 and Siegel et al., 2010, bi-axial material testing (Shah et al., 2006), and in whole body cadavers impacts (Hardy et al., 2008). The seat and shoulder support pads plays a crucial role in injury mitigation to the thorax in high-speed racing crashes.
Belwadi, Aditya, Mahi, Suresh, Begeman, Paul C., Melvin, John, Yang, King H.
Effect of Added Mass of Spindle Wheel Force Transducer on Vehicle Dynamic Response2012-01-02104/16/2012
Wheel force and moment transducers (WFT) are widely used in vehicle testing and analysis [1], [2], [3]. There are many benefits of using these sensors. To install the transducer, vehicle wheel has to be modified. Transducer mounting adaptors are required to interface the sensor with the modified wheel rim. To study the effect of added mass with wheel force transducers, three vehicles, two types of passenger cars, and one SUV, were instrumented with an MTS spindle wheel force transducer (SWIFT 30A) as well as with regular wheels. The instrumented vehicles were driven on multiple proving ground surfaces with three passes for each vehicle. This experimental data was analyzed using RPC Pro software to assess both per pass variation and data trends from 3 passes without WFT (baseline) and 3 passes with WFT added mass. A validated ADAMS model of a production passenger vehicle, with and without added weight of the wheel force transducers, was also used to assess the added weight effect. The ADAMS vehicle model with Ftire tire model was simulated on 3-bumps and Belgian Blocks events.
You, Shawn S.
Tolerances Copper and Copper Alloy Sheet, Strip, and PlateAMS2222J (Historical)11/3/2011
This specification covers established inch/pound manufacturing tolerances applicable to copper and copper alloy sheet, strip, and plate ordered to inch/pound dimensions. These tolerances apply to all conditions, unless otherwise noted.
AMS D Nonferrous Alloys Committee
Overhead Protection for Agricultural Tractors - Test Procedures and Performance RequirementsJ167_201104 (Historical)4/1/2011
This SAE Standard applies to an overhead cover installed on a protective frame or enclosure conforming to SAE J2194 or alternately SAE J1194 and the following additional requirement of a drop test to verify the effectiveness of the overhead cover in protecting the operator from falling objects. The test procedures and performance requirements outlined in this document are based on currently available engineering data.
OPTC4, Protective Structures
Transportation Category WinnerTBMG-50684/1/2009
Simulation with a Vertical Oscillating Race Car Model2008-01-296312/2/2008
The subject of this paper is the creation of a vertical oscillation model of a race car in MATLAB and applying it to transient real-time simulations. The race car model is based upon a multi-body simulation model. That means the entire race car is divided into six discrete and rigid masses connected together with springs and dampers. To calibrate the model and to compute the surface of the real track the following data acquisition signals are required: four pushrod loads of each wheel, the speed, and the longitudinal and lateral acceleration. Based on this model the user can adjust the vehicle suspension setup and simulate the new movements and velocities of the masses as well as the forces acting on them. One result of this simulation can be the relative performance (according to the contact patch loads) in every point of the circuit during one lap as compared to the basis setup.
Graf, Michael, Kosuch, Steffen
Steel Products for Rollover Protective Structures (ROPS) and Falling Object Protective Structures (FOPS)J1119_200804 (Historical)4/14/2008
The purpose of this SAE Information Report is to provide concepts for rational selection and application of materials for Rollover Protective Structures (ROPS) and Falling Object Protective Structures (FOPS) and to provide information about the properties that should be considered in selecting and utilizing material in protective structures. While other materials could conceivably be used successfully, this report is limited to a consideration of steel with discussion on its mechanical properties and processing characteristics. Emphasis is placed on the toughness aspect (ability to resist brittle fracture) as this property is of paramount importance to structure integrity. It is emphasized that specific values for material properties have relevance to performance only in conjunction with specific design considerations such as structure size or weld joint detail and location. Because there are many design-material systems which can be successfully employed to achieve the prescribed performance of protective structures, this report does not make categorical selection of steels.
OPTC4, Protective Structures
ACS-100 SORA and its technological innovations: into the future general aviation scenario2007-01-274411/28/2007
The recently created category of Light Sport Aircraft (LSA) in the United States of America (USA) opens up new perspectives and furthers the development of general aviation. Within this scenario, new enterprises are arising to meet the demand for more versatile airplanes. The ACS-100 SORA is a Brazilian response to the worldwide demand for a new generation of personal aerial transportation. This paper presents the most relevant parts of the engineering development and construction cycle of an all composite sport aircraft with high standard performance, comfort, safety and low cost.
Zaramella, Alexandre, Marcondes Prado, Rafael, Almeida, Conrado Luiz Santiago
Minimum Performance Criteria for Operator Front Protective Structure (OFPS) for Certain EquipmentJ2267_200704 (Historical)4/30/2007
This SAE standard applies to all forestry machines exposed to the hazard of objects penetrating the front of the operator station (other than the roof). This would include:
MTC4, Forestry and Logging Equipment
Occupant Injury in Rollover Crashes: A Reexamination of Malibu II2007-01-03694/16/2007
The original Malibu II study, conducted by Bahling et al, found that neck compression loading in rollover crashes is caused by the occupant moving toward the ground and therefore, roof crush was not causally related to the loading. Some have disputed this finding claiming that the occupant does not “dive toward the roof,” but rather, the roof “moves in” toward the occupant, and that roof deformation is the primary cause of cervical spine injuries in rollover crashes. The original study included a detailed analysis of film and force transducer data for 10 Potentially Injurious Impacts (PII's). This paper presents an independent analysis of these 10 PII's and one additional PII. This analysis uses the film and transducer data to evaluate the timing of roof deformation and neck loading, the magnitude of roof deformation at the time of peak neck load, and the motion of the vehicle and occupants in the inertial reference system. The data establish that the peak neck load occurs shortly after the roof-to-ground contact, and that there is 1.0-1.5 in. (2.5-4.0 cm) of roof crush at the time of peak neck load. This small magnitude of roof deformation occurs as the body of the vehicle moves toward the ground during the build-up of the neck load. The roof at the location of the dummy's head was found to be in contact with the ground at the time of peak neck load for nine of the PII's. When the roof at the location of the head was not in contact with the ground at the time of peak neck load, the loading was the result of the roof panel experiencing a change in velocity as a remote part of the rollcaged roof contacted the ground. Motion of the dummy and the roof in the inertial reference system establishes that the roof does not “move in” toward the occupant, but that the roof and the dummy's head both move toward the ground, that they stop when they contact the ground, and that the chassis of the vehicle and the torso of the dummy continue to move toward the ground, resulting in neck compression loads and roof crush. Therefore, no causal relationship exists between the vehicle deformation and the neck loading.
James, Michael B., Nordhagen, Ronald P., Schneider, Dennis C., Koh, Sung-Woo
Theoretical Analysis of a Method of Computing Dynamic Roof Crush During Rollovers2007-01-03664/16/2007
A method of computing dynamic roof crush in rollover accidents has been proposed (Bidez, et al., 2005; Cochran et al., 2005). The method used data obtained from accelerometers mounted to the roof rails of sport utility vehicles, along with other measurements, to compute the instantaneous deformation of the roof rails during dolly rollover crash tests. We examined the feasibility and practicality of this methodology in three ways. First, the theoretical derivation was examined. Errors appeared to have been made in deriving and/or interpreting the equations used to compute instantaneous roof crush. Next, a three-dimensional dynamic rollover simulation program was run to produce ideal acceleration data (Yamaguchi et al., 2006, 2005). Using these data, the equations in original, uncorrected form predicted dynamic roof deformations when none existed. When the equations were corrected, the simulation data yielded proper roof positions and no roof deformations. Finally, a dolly rollover test was conducted to generate real-world accelerometer data. The vehicle was heavily braced internally to avoid producing significant roof crush. Vibrational “noise” present in the real-world accelerometer data caused a large amount of calculational error in the dynamic roof crush calculations. Sensor positioning and angular alignment errors also may have contributed. These results indicate that the method of computing dynamic roof crush from accelerometer data is theoretically feasible when correct equations and ideal data are used, but is impractical using measured real world accelerometer and angular rate sensor data.
Yamaguchi, Gary T., Ashby, Blake M., Luepke, Peter A., Moore, Tara L.A., Bove, Robert T., Corrigan, Catherine Ford
Chevrolet Montana - Handling Preview for a Racecar2004-01-338011/16/2004
The suspension for a road car focuses in a good compromise between Ride & Handling. When this car is a light pickup, there is also an important compromise between driver and full load condition. For a race car, the suspension system must have a different compromise, were Ride is not considered, but it must be able to keep the tire in contact with the ground, transforming engine power into acceleration, brake power into deceleration and steering inputs in correct corner apex. This paper describes the suspension modification in a production Chevrolet Montana and the methodology used to specify springs, anti roll bars and dampers, which has competed successfully in the 32a Mil Milhas de Interlagos.
Nuti, Angelo Cesar, Orives, Ramon Alberto, Borini, Gerson Mucciolo, Filho, Octávio Sarmento
global vehicles Technical highlights from GenevaAUTOMAY04_015/1/2004
The high-profile event combined new technology, fresh design, debuts of major production models, and styling concepts in a compact venue. The Geneva Motor Show manages to combine all the elements of a high-profile international event-new technology, fresh design, the debuts of major production models, and sometimes quirky styling concepts-with the ability to remain physically small to be cohesive, manageable, and enjoyable. Because of its compact dimensions, it is also one at which chief executives, engineering vice-presidents, and design directors of just about every leading auto company have the time to circulate during the media days and can be seen making shrewd assessments of the opposition's latest wares and the direction they appear to be taking for the future. One of those directions is the crossover concept, a veritable potpourri of designs and applications. Alfa Romeo joined the trend at Geneva with its new Crosswagon based on the 156. Designed by Alfa's Arese Style Center, it incorporates the shape of the regular Sportwagon (station wagon) but with an SUV look, having its suspension raised by 6 cm (2.4 in) to give greater ground clearance and 225/55 R17 tires with a special compound and tread. It has underdoor aluminum protection strips, special front and rear bumpers with aluminum inserts, and, naturally, a compass.
Birch, Stuart
Suspension Calibration via Segmented Method2003-01-370311/18/2003
The system spring/damper/anti roll bar/jounce bumper must isolate the vehicle from the road inputs and keep the body in correct attitude when submitted to lateral acceleration. The calibration is performed changing one component, but the influence from the other components can result in inappropriate conclusions. This method can be divided in two main parts: stiffness calibration (without damping) and damping calibration (with the previously defined stiffness). The first part consists in calibrate the stiffness at the following order spring, jounce bumper and anti roll bar, aiming the minimum body displacements and acceleration. This paper focus in the stiffness calibration and the parameters to select springs, jounce bumper and anti roll bars.
Nuti, Angelo Cesar, Orives, Ramon Alberto
Identification of the Dynamic Parameters of a Car2003-01-12833/3/2003
Accurate values of the dynamic parameters of a car (mass, center of mass, inertia) are needed in order to improve the dynamic control and simulation of the car. It is important to know the value of each of them in order to notify the fields of numerical tools. In this paper a robotics approach is developed. It is based on a multi-body description of the system that allows the automatic computation of the dynamic identification model, which is linear with respect to the parameters to identify. They are estimated using a weighted least squares method. Practical results are given for the parameters of a 406 Peugeot car.
Venture, Gentiane, Bodson, Philippe, Gautier, Maxime, Khalil, Wisama
Steel Bars, Carbon, Hot Rolled, for Cold Shaping, Including Cold ExtrusionAMSS11310A (Historical)2/21/2003
This specification covers hot-rolled carbon steel bars and heat treated carbon steel bars which are to be used in cold shaping, including cold extrusion, of ammunition components.
AMS E Carbon and Low Alloy Steels Committee
Head Toss × Roll Behaviour – Difficult Compromise2002-01-353711/19/2002
For high CG passenger vehicles the body control is a very important parameters for customer perception. The compromise between cornering (body roll) and uneven road (head toss) is the main goal. This paper describes how dampers, spring rate and anti roll bar can influence the desired compromise. Single channel Four Post system and vehicle dynamics measurements give the necessary support for this analysis.
Nuti, Angelo Cesar, Orives, Ramon Alberto, Garzeri, Flavio Jose
Steel Products for Rollover Protective Structures (ROPS) and Falling Object Protective Structures (FOPS)J1119_200209 (Historical)9/20/2002
The purpose of this SAE Information Report is to provide concepts for rational selection and application of materials for Rollover Protective Structures (ROPS) and Falling Object Protective Structures (FOPS) and to provide information about the properties that should be considered in selecting and utilizing material in protective structures. While other materials could conceivably be used successfully, this report is limited to a consideration of steel with discussion on its mechanical properties and processing characteristics. Emphasis is placed on the toughness aspect (ability to resist brittle fracture) as this property is of paramount importance to structure integrity. It is emphasized that specific values for material properties have relevance to performance only in conjunction with specific design considerations such as structure size or weld joint detail and location. Because there are many design-material systems which can be successfully employed to achieve the prescribed performance of protective structures, this report does not make categorical selection of steels.
OPTC4, Protective Structures
An Off-Road Competition Hydraulic Vehicle2002-01-14503/19/2002
A 4-wheel drive off-road vehicle was designed and fabricated using extensive hydraulic technology for the SAE (Society of Automotive Engineers) Mini-Baja competition. The vehicle incorporates an open hydrostatic transmission using a single pump and four independent drive motors. A constant power controller that maintains full engine power to drive the vehicle or stores excess energy in two accumulators controls the pump. Each of the drive motors is independently controlled using a proportional meter-out pressure control valve. The use of pressure control allows the flow to each of the motors to be proportioned based on the dynamics of the vehicle. A CAN bus controller is used in conjunction with a steering sensor to provide differential motor speed control in maneuvering conditions that insures 4-wheel drive availability at all times. Steering of the vehicle is achieved by articulating the chassis using a rotary actuator and multi-motion actuator controlled by the driver. Incorporating these features in the vehicle results in a very small turning radius relative to traditional competition vehicles. The use of the hydrostatic transmission allowed the engine to be moved to the front of the vehicle giving a better weight distribution and making the 4-wheel drive effective throughout the range of the competition. Storing the excess energy in accumulators provided a “power boost” capability beyond the fixed engine power level that could be used to accelerate out of turns or pass on straight-aways. The CAN bus controller allowed the car to be “tuned” to track conditions without the need for extensive hardware changes or modifications.
Labus, Thomas J., Wasielewski, Paul
A Discussion On Using A Pendulum as a Method for Impact Testing Vehicle Sub-Systems2002-01-06873/4/2002
The purpose of this paper is to discuss the use of a pendulum as a repeatable method for impact testing vehicle subsystems and components. Tests on three different vehicle subsystems are presented as examples of impact testing that has been performed using a pendulum. Impact testing on two different roll bar designs to compare effectiveness, impact testing on various van side cargo doors to compare door latch integrity, and impact testing on various fuel tanks to compare the integrity of the fuel tank with and without shields installed. These tests were not intended to replicate the forces, energy, or impact pulse on the vehicle in the actual collision but rather evaluate how the vehicle subsystem reacted to impacts that were similar to that which occurred in the collision. Using proper instrumentation, it can be used to determine the forces or energy required to cause a localized failure or event, determine if an engineered solution has corrected the problem, and used to compare one design to another.
Hitchings, Clarence R., Wallingford, Jerry G., Terry, Sam
Identification of Subjective-Objective Vehicle Handling Links Using Neural Networks for the Foresight Vehicle2002-01-11263/4/2002
The paper describes the application of neural networks to understand the links between test drivers' subjective ratings of vehicle handling and measurable vehicle performance metrics as part of the Foresight Vehicle initiative. The shortcomings of classical linear methods used in previous studies (Crolla et al [1, 2 and 3]) are described along with the processes and developments made in a genetic algorithm based methodology used to find the predominantly non-linear links between subjective and objective handling. The techniques used were designed to make allowances for noise and other distractions inherent within drivers' subjective ratings. Further insights into the preferred ranges of the values of important vehicle handling metrics are presented.
King, R. P., Crolla, D. A., Ash, H. A. S., Whitehead, J.
NAIAS HIGHLIGHTS: CONCEPTSAUTOMAR01_063/1/2001
Since becoming an international event in 1989, the North American International Auto Show in Detroit has hosted 620 North American and worldwide vehicle introductions. This year's event was again a showcase for many new concept and production vehicle debuts. It takes 10 weeks to prepare Cobo Center in Detroit for the NAIAS media and public exposition, with more than 1500 carpenters, stagehands, electricians, Teamsters, riggers, and ironworkers employed full time (12-14 h days; some double shifts) until the job is done. On display are exhibits worth in excess of $200 million, including the latest concept and production vehicles that are the highlights of the event. Similar to last year, crossover concepts were in force with the Cadillac Vizon SUV/performance-wagon hybrid and GMC's transformable Terracross SUV, which is part pickup and part five-seat convertible. Some concepts employed highly innovative technology for safety (Volvo SCC) and body building (carbon-fiber Jeep Willys). Reconfigurable LCD instrument panels and clusters were also big news in this year's concepts, with the Cadillac Vizon and Oldsmobile O4 having them. Improved interior accessibility was a focus with the rear-hinged doors of the Buick Bengal, Oldsmobile O4, and Mazda RX-8. Concepts such as the Nissan Z, Dodge Super8 Hemi sedan, Ford 49, and Volkswagen Minibus combined styling cues or names from the past with present-day technology.
HOW TO WORK RACE TIRES On NASCAR Ovals2000-01-357111/13/2000
Working NASCAR tires correctly will help a team qualify well and have a chance to win on Sunday. Aerodynamics, engines, and shocks are not the only things. Tire usage dictates suspension geometry, springs, weight jacking, and shock choices. Tire slip losses in corners are huge, over 100 HP in qualifying trim and over 150 HP in race trim. Proper tire usage reduces drag HP for qualifying and controls right side tire heating in race trim. Tire slip loss heats the tread rubber and is the primary factor limiting car performance on short tracks. Evaluation of several adjustments on tire and car cornering performance is determined using the Hallum Contact Patch Model presented in SAE 983028 Understanding Race Tires. One psi of tire pressure is significant to car performance. Tire and car performance changes with toe, Ackerman, camber, aerodynamic force, load jacking, and weight, are compared to the performance change with tire pressure. The Hallum Model considers heating so dynamic tire performance phenomena can be evaluated.
Hallum, Chuck
One World, many standardsOFHSEP00_069/1/2000
From Auckland to Zanzibar, the problems faced by the off-highway industry remain remarkably constant. Yet standards do not. Two industry experts discuss some of the roadblocks to global harmonization of standards. “I've been traveling the world for a good part of the last 39 years,” says Gerald H. Ritterbusch, “and I can tell you that rock is about the same regardless of where you go.” With this admittedly simplistic view of geology, the Director of Standards and Regulations for Caterpillar, Inc., introduces the complex subject of global harmonization of standards. The analogy is appropriate: although it can be argued that rock falls into many categories, the construction industry worldwide agrees almost universally on which machines are best suited for certain jobs. But the technical standards applied to the design of those machines are as varied as the faces of the machine operators.
Molter, Dave
Design and Test of an Improved Crashworthiness Small Composite Airframe2000-01-16735/9/2000
The goals of this NASA Phase II SBIR program were to develop design methodology to improve occupant survivability in small composite airplanes. Current technology small airplanes absorb crash energy primarily in the cabin structure. The current study tried to increase strength of the occupant compartment and design energy absorbing structure outside the passenger compartment. Dynamics of the crash event were analyzed using a PC version of DYNA3D. Four full scale tests in two crash scenarios were conducted at the NASA Impact Dynamics Test Facility with test parameters set to allow direct comparison with prior NASA/FAA tests. Results indicate that occupant survivability can be improved with moderate weight penalty.
Terry, James E.
Development of the 2001 Pontiac Aztek Body Structure2000-01-13433/6/2000
This paper documents the development process of the 2001 Pontiac Aztek body structure for improved noise & vibration performance. Successful vehicle development under an accelerated timing schedule demands clearly defined body structure vibration performance targets and critical dependence on the math based modeling process. Specifications for global body structure vibration performance were generated through a two step process. First, a benchmarking activity was undertaken to comprehend competitive vehicle performance. Secondly, a frequency domain “mode map” was constructed to minimize vehicle subsystem interaction. Computer simulation models were developed to predict the body structure performance. A coarse full body structure model was used to define body structure section size and joint requirements. Detailed analysis models of body joint areas were used to synthesize the joint design. This process led the design efforts to minimizing body structure mass while optimizing vibration performance. A comprehensive measurement plan was executed to confirm the frequency performance of the body structure. Modal tests were performed at several points in the prototype body build process to confirm the analysis modeling efforts. The 2001 Pontiac Aztek body structure vibration performance is dramatically improved over that of the previous generation from which it was conceived. Increases in body structure stiffness of 47%, 40% and 89% are seen in the three lowest frequency global body structure modes.
Banner, Tony, Deutschel, Brian, Hamilton, Dave, Juras, Paul
Labeling of ROPS and FOPS and OPSJ1164_200002 (Current)2/8/2000
This SAE Standard establishes the specifications and content for labeling of ROPS, FOPS, and OPS, which may commonly be a part of construction, forestry, mining, and industrial machines. The label content herein shall be applied to a ROPS and/or FOPS and/or OPS on any of these machines.
OPTC4, Protective Structures
Rollover Protective Structures (ROPS) for Wheeled Agricultural TractorsJ1194_199911 (Historical)11/22/1999
Fulfillment of the intended purpose requires testing as follows: A laboratory test, under repeatable and controlled loading, to permit analysis of the ROPS for compliance with the performance requirements of this SAE Standard. Either the static test (6.1) or the dynamic test (6.2) shall be conducted. A crush test to verify the effectiveness of the deformed ROPS in supporting the tractor in an upset attitude. A field upset test under reasonably controlled conditions, both to the rear and side, to verify the effectiveness of the protective system under actual dynamic conditions. (See 6.4.1.1 for requirements for the omission of this test). In addition to the laboratory and field loading requirements, there is a temperature-material requirement. (See 7.1.2.) The test procedures and performance requirements outlined in this document are based on currently available engineering data.
Agricultural Tractor Standards Committee (ATSC)
Tolerances Copper and Copper Alloy Sheet, Strip, and PlateAMS2222H (Historical)11/1/1999
This specification covers established inch/pound manufacturing tolerances applicable to copper and copper alloy sheet, strip, and plate ordered to inch/pound dimensions. These tolerances apply to all conditions, unless otherwise noted.
AMS D Nonferrous Alloys Committee
Recommendations on Selection and Use of Cavity Reinforcement Materials1999-01-16725/17/1999
Cavity reinforcement materials are used in the automotive industry to stiffen hollow cavities in unibody constructions. Typical areas of use include the engine rails, rocker panels, roof support or any other cavity in need of reinforcement. Use of these materials can allow for reductions in vehicle weight without sacrificing long-term durability and stiffness. Additional NVH benefits could be gained through the change in stiffness and through acting as a physical barrier to the propagation of noise, water and dust. The objective of this paper is to describe the properties of a new type of cavity reinforcing material and to identify key properties of reinforcing materials.
Zalobsky, Anita, Chang, Chin-Jui Jerry
Minimum Performance Criteria for Falling Object Protective Structure (Fops)J231_199903 (Current)3/1/1999
This Recommended Practice applies only to machines covered by SAE J1040c (ROPS). The evaluations are for resistance to localized penetration. The performance requirements, of a representative specimen within the manufacturer's specifications, are based on the performance of experience proven structures under the laboratory evaluation procedure. It is intended that all portions of this Recommended Practice shall be reviewed and revised as additional knowledge of FOPS performance becomes available. This SAE Recommended Practice establishes a consistently repeatable laboratory evaluation procedure and performance requirements in that evaluation for structures intended to provide operators with reasonable protection from such falling objects as trees and rocks.
OPTC4, Protective Structures
Performance Criteria for Falling Object Protective Structure (FOPS) for Industrial MachinesJ1043_199903 (Current)3/1/1999
This standard applies to General Purpose Industrial Machines, as described in SAE J1116, which are equipped with Rollover Protective Structures (ROPS). This SAE Standard establishes performance criteria for Falling Object Protective Structures (FOPS) intended to provide operators of general purpose industrial machines with overhead protection from objects such as bricks, concrete blocks, and small hand tools that may fall from heights of not more than 9 m (30 ft) above the ground, encountered in operations such as highway maintenance, landscaping, and other services on construction sites where the falling object develops an energy not to exceed 1360 J (1000 ft-lbf).
OPTC4, Protective Structures
Steel Bars, Carbon, Hot Rolled, for Cold Shaping, Including Cold ExtrusionAMSS11310 (Historical)11/1/1998
This specification covers hot-rolled carbon steel bars and heat treated carbon steel bars which are to be used in cold shaping, including cold extrusion, of ammunition components.
AMS E Carbon and Low Alloy Steels Committee
Roll-Over Protective Structures (Rops) for Wheeled Agricultural TractorsJ2194_199709 (Historical)9/1/1997
Any ROPS meeting the performance requirement of ISO 5700 (Static ROPS Test Standard) or ISO 3468 (Dynamic ROPS Test Standard) meets the performance requirements of this SAE Standard if the ROPS temperature/material and seat belt requirements of this document are also met. Fulfillment of the intended purpose requires testing as follows: A temperature-material requirmenet. This can be satisfied by using the appropriate materials or by performing any of the structural performance tests at -18 degrees C. A laboratory test, under repeatable and controlled loading, to permit anaysis of the ROPS for compliance with the performance requirements of this document. Either the static test sequence or the impact test sequence shall be conducted. A set belt anchorage test. The test procedures and performance requirements outlined in this document are based on currently available engineering data. The purpose of this document is to establish the test and performance requirements of a roll-over protective structure (ROPS), designed for wheeled agricultural tractors to minimize the frequency and severity of operator injury resulting from accidental tractor upset.
Agricultural Tractor Standards Committee (ATSC)
NDT at the Indy 5009511353/1/1995
The 500 mile race in Indianapolis is called the “Greatest Spectacle in Racing”. Each year, Indy Car teams gather at the Speedway to try and find enough speed to make the 33 car field. To make the show, the car must be capable of averaging over 220 mph. To safely achieve these speeds, the components of these cars must be free from the defects that could lead to structural failures. During the month of May, volunteers from across the country will spend their free time to come to Indy and perform nondestructive testing inspections on Indy Car Parts.
Miener, Michael W.
Use of Aluminum in Automotive Space Frames9507212/1/1995
Aluminum space frame chassis offer advantages due to the space frame concept and use of aluminum. A comparison is made to a steel space frame and the results reported. Torsional stiffness, bending stiffness and weight are compared. A model was developed using finite element analysis which predicted with accuracy the stiffness and weight of the frames. Using the model, an effective aluminum space frame was developed which was superior in stiffness to steel by 7½% and weighed over 20% less than the steel frame. Stresses were kept below the welded fatigue limit for aluminum allowing welding to be used.
Overbagh, William H.
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