Browse Topic: Protective structures

Items (253)
Find
Electrically Non-Conductive Ladder Fall ProtectionTBMG-361943/1/2020
NASA’s Kennedy Space Center developed an electrically non-conductive ladder fall protection system for the Launch Complex (LC) 39B lightning towers. The towers include a 100-foot fiberglass mast at the top of the tower structure. The fiberglass masts insulate the metallic tower structure from the lightning strike protection system that is housed at the top of the fiberglass masts.
Magnetic Shield Using Proximity Coupled, Spatially Varying Superconducting Order ParametersTBMG-361653/1/2020
NASA Goddard Space Flight Center has developed a magnetic shielding design that features simplicity, ease of use, reproducibility, longevity, and scalability. It does not require activation, monitoring, or wiring. The invention uses the superconducting “proximity effect” and/or the “inverse proximity effect” to form a spatially varying order parameter. When designed to expel magnetic flux from a region of space, the proximity effect(s) are used in concert to make the superconducting order parameter strongly superconducting in the center and more weakly superconducting toward the perimeter. The shield is then passively cooled through the superconducting transition temperature.
Overhead Protection for Agricultural Tractors - Test Procedures and Performance RequirementsJ167_202002 (Current)2/20/2020
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
3D-Printed Polymer-Based Foam Structure Responds to Shock WavesTBMG-351479/1/2019
A 3D-printed polymer-based foam structure was developed that responds to the force of a shock wave to act as a oneway switch, a long sought-after goal in shock research. The material configuration has the potential to be scaled up in order to be used in different ways for a variety of applications including for the protection of structures.
Three-Point Hitch (Type A) Backhoe Personnel ProtectionJ1518_201908 (Current)8/28/2019
This SAE Recommended Practice applies to three-point hitch (Type A) backhoes as defined in SAE J326 when mounted on either an agricultural tractor as defined in ANSI/ASAE S390 or other off-road self-propelled work machine as defined in SAE J1116. This criterion is intended for the manufacturer of the backhoe, whether or not the backhoe is manufactured or marketed by the same company that manufactures or markets the propelling machine.
OPTC1, Personnel Protection (General)
Personnel Protection - Skid Steer LoadersJ1388_201907 (Current)7/3/2019
This SAE Standard is intended to provide personnel protection guidelines for skid steer loaders. This document is intended as a guide towards standard practice, but may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering its use. This document provides performance criteria for newly manufactured loaders and it is not intended for in-service machines.
OPTC1, Personnel Protection (General)
Machining Capabilities Enhance Space-Related ProgramsTBMG-347367/1/2019
Insaco Quakertown, PA
NASA's Robotic Sniffer Finds Space Station LeakTBMG-328369/1/2018
Stanford Research Systems Sunnyvale, CA
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
Temperature Measuring Devices NomenclatureARP485A (Current)5/3/2018
This SAE Aerospace Recommended Practice (ARP) defines the nomenclature of temperature measuring devices. General temperature measurement related terms are defined first, followed by nomenclature specific to temperature measuring devices, particularly thermocouples.
E-32 Aerospace Propulsion Systems Health Management
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
Roll-Over Protective Structures (ROPS) for Wheeled Agricultural TractorsJ2194_201611 (Current)11/28/2016
Any ROPS meeting the performance requirement of ISO 5700 (Static ROPS Test Standard) or ISO 3463 (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.
OPTC4, Protective Structures
Rollover Protective Structures (ROPS) for Wheeled Agricultural TractorsJ1194_201611 (Current)11/23/2016
Fulfillment of the intended purpose requires testing as follows:
OPTC4, Protective Structures
Rear Underrun Protection Test (ECE R58) using CAE Simulation2016-01-80989/27/2016
The regulatory requirement in Economic Commission for Europe (ECE R58) regulation applies to the Rear underrun protection devices which are intended to be fitted to commercial vehicles of N categories. The purpose of this regulation is to offer effective protection against underrunning of vehicles. This paper describes Computer aided engineering (CAE) methodology for testing rear underrun protection devices with loading sequences to be decided by Original equipment manufacturer. A sample model is prepared and analyzed to represent actual test conditions. Constraints and boundary conditions are applied as per test of vehicle. Finite element simulation is carried out using LS DYNA solver. Structural strength and integrity of Rear under protection device assembly is observed for different regulatory load requirement.
Pandare, Sahil, Jaju, Satish
Overhead Guard Physical Tests vs LS-DYNA FE Simulations2016-01-90179/16/2016
The lifting and excavating industry are not as advanced as automotive in the use of modern CAE tools in the early stages of design and development of heavy machinery. There is still a lack of confidence in the integrity of the results from FE simulations and optimisation and this becomes a barrier to the adoption of virtual prototyping for vehicle verification. R&D of Tata Steel has performed tests on two forklift truck overhead guards supplied by a major manufacturer. Based on the international standard for Falling Object Protective Structures (FOPS) as an initial input to the method of testing, the main aim of this study was to generate as much test data as possible to correlate the Finite Element (FE) simulations of two tests - a static and a dynamic test. The static test was developed to deform the overhead guard plastically in a slow controlled manner, so it would be easier to correlate the measured data to FE simulation. A dynamic test is always very difficult to correlate due to the fact that the whole test is over in less than a second and the dynamic response of the structure makes the data extremely noisy. However, this paper demonstrates that paying close attention to all of the input data for an FE model results in a close correlation between the test and the FE simulation even in highly dynamic conditions.
Cafolla, Janka, Smart, Derick, Warner, Barry
Body-in-White Reinforcements for Light-Weight Automobiles2016-01-03994/5/2016
Automotive OEMs are proactively working on vehicle light-weighting, powertrain optimization, alternate/renewable energy sources and combinations of the three to meet challenging corporate average fuel economy (CAFE) standards. Light-weighting of the body-in-white (BIW) is an obvious choice for vehicle light-weighting as this structure contributes to more than 30-35% of the total weight of a car. Changing manufacturing and assembly lines requires substantial investment. As such, OEMs are exploring short-term light-weighting strategies that do not require any major changes to the BIW. Local reinforcement for the BIW are pertinent solutions that does not require any major changes in the existing assembly lines. This paper focuses on the development of BIW reinforcement solutions using engineering thermoplastic materials that can be mounted at appropriate locations on a vehicle’s BIW to achieve significant weight savings without compromising crash performance. Various design and material configurations - including plastic, metal-plastic and composite-plastic structural members - mounted on the BIW are evaluated through CAE studies for various crash scenarios such as high-speed frontal crashes, side impact, pole impact and rollover. The CAE studies, performed using generic vehicle models, quantify the potential weight-savings in a vehicle by either replacing the existing reinforcements using a lighter system or by incorporating additional reinforcements in the BIW by down-gauging the existing BIW. Approaches to correlate the CAE studies using component level testing and validation of generic reinforcements are also investigated. Data from all of this work indicate that the use of BIW reinforcements can achieve significant weight reduction (∼ 1.5%) in a vehicle, while also ensuring no compromise in crash performance.
Munjurulimana, Dinesh, Kulkarni, Amit, Nagwanshi, Dhanendra, Thambi, Joel Luther, Winters, Ruud, Delaney, Matthew
Reduce Cost of Product Design using Unit FE Simulation2016-01-13714/5/2016
The unit analysis methodology can be used for designing component or product in a product development process. This method may be used for designing the crush can, bumper beam, crush can long member, B-frame or A-pillar in frontal impact analysis. Unit assembly model technique can be effectively used in many CAE load cases to evaluate CAE simulations such as pedestrian impact analysis (ECE R78 / ENCAP), interior trim related head impact simulations (FMVSS201U), under run protection simulation for commercial vehicles (Front Underrun Protection Device ECE R93, Rear Underrun Protection Device ECE R58, Side Underrun Protection Device ECE R73), airbag deployment optimization etc. These CAE analyses correlate better with actual test. This paper gives idea about how the cost of product design can be reduced by using unit analysis. To reduce time of vehicle development such as cost of prototype, testing cost, optimization cost unit analysis is more economical. In this paper, one illustrative CAE example shows that how cost and time required for designing product and development using unit assembly simulation is reduced drastically as compared to full vehicle simulation. Using unit analysis, complexity of work is reduced from high to low. CPU run time cost is reduced with high margin as compared to full vehicle simulation. In automotive product development, one can use unit analysis method.
Jaju, Satish, Jain, Pritesh, Musale, Gopal
Crashworthiness Design of Automotive Body in White using Topology Optimization2016-01-15354/5/2016
Based on equivalent static loads method (ESL), a nonlinear dynamic topology optimization is carried out to optimize an automotive body in white (BIW) subjected to representative legislative crash loads, including frontal impact, side barrier impact, roof crush and rear impact. To meet the crashworthiness performances, two evaluation indexes are defined to convert the practical engineering problems into mathematic optimization problems. The strain energy is treated as the stiffness evaluation index of the BIW and the relative displacement is employed as the compliance index of the components and parts. The optimization problem could be changed into maximizing structural stiffness of the design space while constraining the relative displacements of the passenger cabin lower than a certain value to guarantee the stiffness of passenger cabin, constraining the relative displacements of the front and rear cabin greater than a certain value to increase the energy absorption during the crash process. The results provide a conceptual design which emphasizes the most efficient load paths and could be served as an effective guidance to the next-step BIW detailed design.
Tian, Linli, Gao, Yunkai
Bio-Inspired Design of Lightweight and Protective Structures2016-01-03964/5/2016
Biologically inspired designs have become evident and proved to be innovative and efficacious throughout the history. This paper introduces a bio-inspired design of protective structures that is lightweight and provides outstanding crashworthiness indicators. In the proposed approach, the protective function of the vehicle structure is matched to the protective capabilities of natural structures such as the fruit peel (e.g., pomelo), abdominal armors (e.g., mantis shrimp), bones (e.g., ribcage and woodpecker skull), as well as other natural protective structures with analogous protective functions include skin and cartilage as well as hooves, antlers, and horns, which are tough, resilient, lightweight, and functionally adapted to withstand repetitive high-energy impact loads. This paper illustrates a methodology to integrate designs inspired by nature, Topology optimization, and conventional modeling tools. Two designs are explained to support this methodology: Helmet design inspired by human bone cellular structure (trabecular structure) and vehicle body inspired by a water droplet, ribcage, and human bone. In the helmet design, a finite part of is optimized using topology optimization to generate the porous structure. In the vehicle body design, a water droplet framework, the bio-inspired simulation-based design algorithm used in this work generates innovative layouts. At the vehicle scale, the generated spaceframe has a structure similar to the one of a long bone. In essence, the aerodynamic water droplet shape is protected by the specialized ribcage. At the component scale, each spaceframe tubular component is filled with a functionally graded cellular structure. This internal cellular structure reminds the one of a bone. The spaceframe is attainable with few parts of greater complexity. Such complex, lightweight, multiscale structural layout can be manufactured using 3D printing technologies.
Mehta, Prasad S., Solis Ocampo, Jennifer, Tovar, Andres, Chaudhari, Prathamesh
Cat pipelayers offer power and comfort to operators15MEIP12_2612/1/2015
Independent, variable-speed winches for the boom and hook provide precise control, and an enhanced counterweight system ensures a low center of gravity in Caterpillar's new PL72, PL83, and PL87 pipelayers. A new ROPS (roll-over protection structure) provides added safety for both open and enclosed operator's stations. The new, purpose-built Pipelayer cab is now pressurized and incorporates new operator-comfort and convenience features. Cat says the new pipelayers were designed to offer the industry increased lift capacity, enhanced slope capability, ease of operation, and transportability. Rated lift capacity (at tipping point) for the PL72 is 90,000 lb (40,823 kg), 170,000 lb (77,111 kg) for the PL83, and 216,000 lb (97,972 kg) for the PL87. A non-suspended, elevated-sprocket undercarriage provides ample track-on-ground for added stability.
Broge, Jean L.
Komatsu America adds to intelligent machine lineup15MEIP12_2912/1/2015
The long track, low ground pressure D65PXi-18 introduced recently by Komatsu America Corp. was designed specifically for functionality in soft or wet conditions, offering improved stability for finish grading applications. It is powered by a 217-hp (162-kW) SAA6D114E-6 Tier 4 Final emissions certified engine. Highlights of the crawler dozer include next-generation intelligent machine control. “The machine senses blade load, minimizes track slip, and ensures operators get the most from every push,” said Jason Anetsberger, Komatsu product manager. “We believe the difference in dozing efficiency between conventional machine operation and intelligent machine control technology is exceptional.”
Broge, Jean L.
CAE Prediction and Test Correlation for Tractor Roll-over Protective Structure (ROPS)2015-01-14764/14/2015
Roll-over protective structures (ROPS) are safety devices which provide a safe environment for the tractor operator during an accidental rollover. The ROPS must pass either a dynamic or static testing sequence or both in accordance with SAE J2194. These tests examine the performance of ROPS to withstand a sequence of loadings and to see if the clearance zone around the operator station remains intact in the event of an overturn. In order to shorten the time and reduce the cost of new product development, non-linear finite element (FE) analysis is practiced routinely in ROPS design and development. By correlating the simulation with the results obtained from testing a prototype validates the CAE model and its assumptions. The FE analysis follows SAE procedure J2194 for testing the performance of ROPS. The Abaqus version 6.12 finite element software is used in the analysis, which includes the geometric, contact and material nonlinear options. Simulation results such as plastic deformation and energy absorption during the sequence of loading conditions were compared with the results of prototype testing. Reasonably good correlation was observed between the experimental and FE results, which shows that the FE model is validated against the experimental model.
Selvakumar, P, Mahajan, Arun, Murasolimaran, R, Elango, C
Deflection Limiting Volume - Protective Structures Laboratory EvaluationJ397_201503 (Current)3/27/2015
This SAE Standard applies to operator protective structures which may commonly be a part of construction, forestry, mining, and industrial machines.
OPTC4, Protective Structures
Vehicle Roof Strength Test ProcedureJ374_201503 (Current)3/13/2015
This SAE Recommended Practice establishes a uniform laboratory test method to evaluate the strength characteristics of roof systems. The test procedure is intended to provide reliable and repeatable results and to permit numerical comparisons. A test is conducted in which the vehicle roof system is loaded under controlled laboratory conditions. Structural strength measurements are obtained under load application angles chosen to concentrate forces on the forward portions of the roof panel and roof supporting structure.
Impact and Rollover Test Procedures Standards Committee
Agricultural Tractor Cabin Structure Design for Durability and Rollover Protective Structure Test2015-26-01631/14/2015
A cabin on an agricultural tractor is meant to protect the operator from harsh environment, dust and provide an air conditioned space. As it is an enclosed space, cabin structure should be a crashworthiness structure and should not cause serious injury to operator in case of tractor roll over. There are International standard like OECD Code 4, SAE J2194 which regulates the crashworthiness of this protective structure. The roll-over protective structure (ROPS) is characterized by the provision of space for a clearance zone large enough to protect the operator in case of tractor overturn. None of the cabin parts should enter into the clearance zone for operator safety. In addition to meeting ROPS test criteria, the cabin structural strength should be optimized for the required tractor life. In this paper, simulation process has been established to design an agricultural tractor cabin structure and its mountings to meet the above requirements. A Design Verification Plan (DVP) has been developed consisting of 3 load cases. Loads and boundary conditions have been arrived at based on the OECD Code 4 and road & field excitations. Design acceptance criteria have been formulated for clearing the ROPS test and durability for the tractor life. Virtual validation has been done by performing (i) A non-linear elasto-plastic simulation in ABAQUS for ROPS test and (ii) Static & modal analysis in MSC Nastran for durability. For ROPS test, equivalent plastic strain approach has been used for predicting the crack initiation and for durability analysis, fatigue based approach has been used for predicting the life. Lab test has been done for the ROPS test and has been correlated with CAE results. At the end, further design iteration has been done for mass and cost reduction. Biggest challenge in this work was to meet the above criteria within the constraint of material availability and manufacturing limitation.
Kumar, Abhay, Mahajan, Arun, Prasanth, S, Darekar, Sudhir, Chellan, Jagadeesan, Kumar, K Ashok, Ranjith Kumar, Jeya Kumar
Multidisciplinary Design Optimization of BEV Body Structure2015-26-02291/14/2015
Blade Electric Vehicle (BEV) with a light body plays an important role in saving the energy and reducing the exhaust emission. However, reducing the body weight need to meet the heterogeneous attributes such as structural, safety and NVH (Noise, Vibration and Harshness) performance. With the rapid development of finite element (FE) analysis technology, simulation analysis is widely used for researching the complex engineering design problem. Multidisciplinary Design Optimization (MDO) of a BEV body is a challenging but meaningful task in the automotive lightweight. In present research, the MDO is introduced to optimize a BEV Body-in-White (BIW). The goal of optimization is to minimize the mass of the BIW while meeting the following requirements: structural performance (the bending and torsion stiffness is increased), NVH performance (the first overall torsion frequency is increased), and safety performance (the roof crush resistance is improved).The sample points were obtained by using Design of Experiment (DOE) with optimal Latin hypercube. The approximation models of mass, bending stiffness, torsion stiffness, modal and safety were established with the polynomial response surface method (RSM). The thicknesses of nine parts of the BIW were selected to be optimized by Muti-island Genetic Algorithm (MGA) method. After the MDO of the BIW, the paper drew the following conclusions: 1.The predictive values of the approximation and the results of FE simulation had a good agreement with an error less than 5.00% and the former met the engineering requirements; 2.The weight of the BIW was reduced by 2.00% and the optimized BIW met all prescribed requirements about structural, NVH and safety performance.
Zhang, Jibing, Hu, Sanbao, Guo, Xuexun, Zhou, Quan
Evaluation of Different Roof Strength Methods in Quasi-Static and Dynamic Rollover Tests Using Finite Element Analysis of a 2003 Ford Explorer Model2014-01-05324/1/2014
Different roof strength methods are applied on the 2003 Ford Explorer finite element (FE) model to achieve the current Federal Motor Vehicle Safety Standard (FMVSS) 216 requirements. Two different modification approaches are utilized. Additionally, the best design of each approach is tested dynamically, in rollover and side impact simulations. In the first approach, several roll cage designs are integrated in all pillars, roof cross-members, and in the side roof rails. A roll cage design with a strength-to-weight ratio (SWR) of 3.58 and 3.40 for driver and passenger sides, respectively, with a weight penalty of 18.54 kg is selected for dynamic test assessments. The second approach investigates different localized reinforcements to achieve a more reasonable weight penalty. A localized reinforcement of the B-pillar alone with a tube meets the new FMVSS 216 requirements with a weight penalty of 4.52 kg and is selected for dynamic analyses. The two selected reinforcement designs are tested in a dynamic unconstrained rollover crash under different pitch angles while using common rollover initial conditions. Based on the limited dynamic analysis, the localized reinforcement has proved to be an effective approach for front row seat protection. However, passengers in the rear seats are better protected by the roll cage solution. Additionally, side impact analysis is examined for both approaches. Overall, the influence of both reinforcement methods on the side impact is small and therefore deemed acceptable. These methods can be incorporated in vehicle's roof structure or taken into consideration for future vehicle designs.
Albrodt, Simon B., Tahan, Fadi, Digges, Kennerly
Minimum Operational and Maintenance Responsibilities for Aircraft Tire UsageARP5265A (Historical)10/25/2013
This SAE Aerospace Recommended Practice (ARP) sets forth criteria for the installation, inflation, inspection, maintenance and removal of aircraft tires as well as criteria for the maintenance of the operating environment so as to achieve the purpose stated in 1.1. (Definitions of terms related to aircraft tires is found in 2.2.)
A-5C Aircraft Tires Committee
Steel Products for Rollover Protective Structures (ROPS) and Falling Object Protective Structures (FOPS)J1119_201307 (Current)7/9/2013
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
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
A Study on Development of Body Structure Using Hydroforming of a Thin-Walled UHSS Tube2013-01-00353/25/2013
Hydroforming process is an emerging manufacturing technology which allows engineers to use continuous closed section without flange for spot weld in a given package envelope. In this research, Hydroforming is applied to a front pillar and a roof side rail for improvement of obstruction angle, body stiffness and roof crush resistance. In addition, the joints of front / center pillar that were integrated into the hydroforming part and structure of package tray were improved. As a result, front pillar width is reduced by 23%, body torsional stiffness is increased by 45% and roof crush resistance is improved by 35%.
Cha, Munsoo, Kim, Cheol-Ung
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
Operator Restraint System for Off-Road Work MachinesJ386_201208 (Historical)8/24/2012
This SAE Standard establishes the minimum performance requirements for pelvic restraint systems (seat belts, anchorages, and the fastening elements of seat belts) necessary to restrain an operator or rider within a roll-over protective structure (ROPS) in the event of a machine roll-over, as defined in ISO 3471, or tip-over protection structure (TOPS), in the event of a machine tip over as defined in ISO 12117. This SAE Standard applies to off-road, self-propelled work machines fitted with ROPS as specified in ISO 3471, TOPS as specified in ISO 12117 and operator restraint.
HFTC4, Operator Seating and Ride
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.
Establishing Occupant Response Metrics on a Roll Simulator2012-01-00994/16/2012
This paper presents the results of an in-depth study of the measurement of occupant kinematic response on the S-E-A Roll Simulator. This roll simulator was built to provide an accurate and repeatable test procedure for the evaluation of occupant protection and restraint systems during roll events within a variety of occupant compartments. In the present work this roll simulator was utilized for minimum-energy, or threshold type, rollover events of recreational off-highway vehicles (ROVs). Input profiles for these tests were obtained through a separate study involving autonomous full vehicle tests [1]. During simulated roll events anthropomorphic test device (ATD) responses were measured using on-board high speed video, an optical three-dimensional motion capture system (OCMS) and an array of string potentiometers. Comparisons among the indirect measurement systems were performed to allow for characterization of each measurement system's utility and accuracy when used in this specific application. These comparisons show that the indirect methods detailed in this study allow for accurate and repeatable ATD excursion measurement. Preliminary evaluations were also made between the roll simulator ATD response and that determined during the autonomous tests. The roll simulator ATD kinematics closely matched those observed and recorded during autonomous tests. These comparisons provide an initial verification of the roll simulator system with respect to reproducing ATD kinematics and a validation of the measurement system methodologies employed on the roll simulator.
Yoder, Steven J., Morr, Douglas R., Heydinger, Gary J., Guenther, Dennis A.
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
Making Machine Vision Systems SmarterTBMG-100015/1/2011
Machine vision technology is used extensively throughout manufacturing to improve product quality, increase productivity and reduce costs. One of the reasons for that is a machine vision system will work tirelessly on mundane repetitive tasks at high speed with great precision.
Optimization of One-Dimensional Aluminum Foam Armor Model for Pressure Loading2011-01-10504/12/2011
The primary objective of this investigation is the optimum design of lightweight foam material systems for controlled energy absorption under blast impact. The ultimate goal of these systems is to increase the safety and integrity of occupants and critical components in structural systems such as automotive vehicles, buildings, ships, and aircrafts. Although outstanding results have been achieved with the use of foams in blast protective systems, current design practices rely on trial and error as there is an absence of a systematic design method. While the governing equations are known for a variety of physical phenomena in appropriate length scales, there are no suitable methodologies to accomplish the aforementioned objectives. A promising approach to systematically design the material's microstructure is the use of structural optimization methods. This investigation presents an appropriate design methodology to optimally design foam material systems for blast mitigation. The objective function is expressed in terms of acceleration. Macroscopic effective material properties are used to drive the nonlinear analysis of the elasto-plastic material under time-dependent loading conditions. Gradient-based optimization methods are used to obtain the final density distribution of the foam material system. The application of this approach is shown through a two-dimensional optimization problem.
Goetz, John C., Tan, Huade, Tovar, Andres, Renaud, John
Finite Element Modeling Comparisons of Rollover Test Devices2011-01-00114/12/2011
Rollover test equipment is of interest in the development of rollover protection system designs. The Controlled Rollover Impact System (CRIS) by Exponent and the Jordan Rollover System (JRS) from the original founder of VIA Systems represent two such systems available. The two systems represent significantly different approaches to the same problem; the CRIS utilizes a structure moving over the ground, while the JRS utilizes a rotating vehicle over a moving ground. Finite Element (FE) modeling of CRIS impacts has been presented previously. In this paper, the ability to model the JRS system is demonstrated. A Finite Element model of the JRS was created and compared with an over-the-ground rollover under the same conditions. An analysis using Finite Element models of a production and roll-caged vehicles and Hybrid III dummies with the CRIS and JRS devices under the same impact conditions then was conducted. The results of the analysis are provided and discussed.
Hutchinson, John, Friedman, Keith, Mihora, Dennis
Items per page:
1 – 50 of 253