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Technical Paper
2014-04-20
Ala Qattawi, Mahmoud Abdelhamid, Ahmad Mayyas, Mohammed Omar
1 The manufacturing of Origami based sheet metal products is a promising technology, mostly in terms of reducing the tooling and process complexity. This procedure can also be called fold forming, as it depends on exclusively shaping the required geometry via sequence of bends. However, the design analysis and modeling of folded sheet metal products are not fully mature, especially in terms of determining the best approach for transferring the analysis from a three-dimensional (3D) to a two-dimensional (2D) context. This manuscript discusses the extension of the Origami technique to the fold forming of sheet metal products represented in modeling approach and design considerations for the topological variations, the geometrical validity, and the variance of stress-based performance. This paper also details the optimization metrics that were developed to reflect the design and manufacturing differences among the possible topological and geometrical options for a single part design. These metrics target five different optimization objectives: material utilization, cost, ease of manufacturability, ease of handling, and mechanical behavior estimation.
Standard
2014-04-14
Scope is unavailable.
Standard
2014-04-11
This Material Specification defines the requirements of carbon fiber fabric and epoxy resin systems used for wet lay-up repair of carbon fiber reinforced epoxy structures, qualified according to AMS 2980/1 and 2980/2.
WIP Standard
2014-04-11
This specification covers a titanium alloy in the form of extruded bars, tubes, and shapes, and of flash welded rings and stock for flash welded rings.
Standard
2014-04-09
AMS 2980/2 gives specific information about the qualification program for carbon fiber fabric, epoxy systems and the material combination used for wet lay-up repair of carbon fiber reinforced epoxy structures.
Standard
2014-04-08
AMS 2980/1 gives information about the technical requirements and qualification procedure for carbon fiber fabric and epoxy resin systems used for wet lay-up repair of carbon fiber reinforced epoxy structures.
WIP Standard
2014-04-07
This standard covers performance requirements and methods of test for master cylinder reservoir diaphragm gaskets that will provide a functional seal and protection from outside dirt and water.
WIP Standard
2014-04-04
This SAE Aerospace Standard (AS) defines the requirements for polytetrafluoroethylene (PTFE) line, metallic reinforced, hose assemblies suitable for use in aerospace hydraulic, fuel and lubricating oil systems at temperatures between -67 °F and 450 °F for Class I assemblies, -67 °F and 275°F for Class II assemblies, and at nominal pressures up to 1500 psi. The hose assemblies are also suitable for use within the same temperature and pressure limitations in aerospace pneumatic systems where some gaseous diffusion through the wall of the PTFE liner can be tolerated.

The use of these hose assemblies in pneumatic storage systems is not recommended. In addition, installations in which the limits specified herein are exceeded, or in which the application is not covered specifically by this standard, for example oxygen, shall be subject to the approval of the procuring activity.

Standard
2014-04-03
This SAE Aerospace Recommend Practice (ARP) is intended to identify both safety related best practices and unique design considerations of metal halides High Intensity Discharge (HID) lamps and power supplies in aircraft applications.
Standard
2014-04-03
This document covers all-metal, self-locking nuts, plate nuts, and gang channel nuts made of a corrosion and heat resistant nickel alloy.
WIP Standard
2014-04-03
This Standard provides names of many of the major components and parts peculiar to agricultural and industrial rotary, flail and sickle bar type mowers. Illustrations used are not intended to include all existing industrial or agricultural machines, or to be exactly descriptive of any particular machine. They have been picked to describe the principles to be used in applying this standard.
WIP Standard
2014-04-02
This SAE Standard covers nonreinforced, extruded, flexible tubing intended primarily for use as fluid lines for automotive windshield washer systems which conform to the requirements of SAE J942.
Technical Paper
2014-04-01
Zamir Zulkefli, Maurice Adams
Abstract Gears are used in numerous applications where mechanical power needs to be transmitted as in the powertrain of cars, buses and other vehicles. These gears can potentially be a significant source of high-frequency vibration and radiated noise in a vehicle, which can be both harmful and objectionable to any listeners in the vicinity. A proposed approach to addressing the gear mesh-frequency vibrations is to utilize the low pass filtering effect of a hydrostatic bearing in a gear mesh-frequency noise mitigation system. This paper describes an experimental investigation of the low pass filtering effect of a hydrostatic bearing using an experimental setup involving a widely available materials testing machine. By using the materials testing machine, appropriately sized hydrostatic bearing and externally pressurized fluid supply system, empirical data was collected that allowed the frequency response of the hydrostatic bearing to be determined. The frequency response of the hydrostatic bearing clearly shows a low pass filtering effect on the applied dynamic loads.
Technical Paper
2014-04-01
Mehdi Safaei, Shahram Azadi, Arash Keshavarz, Meghdad Zahedi
Abstract The main end of this research is the optimization of engine sub-frame parameters in a passenger car to reduce the transmitted vibration to vehicle cabin through DOE method. First, the full vehicle model of passenger car including all its sub-systems such as engine, suspension and steering system is modeled in ADAMS/CAR and its accuracy is validated by exerting swept sine and step input. After that, the schematic geometry of sub-frame is modeled in CAD software and transferred to ADAMS/CAR. Hence, the efficiency of the sub-frame in terms of reducing the induced vibration to vehicle cabin is examined through the various road inputs e.g. swept sine, step and random road input type (B). The results will illustrate that the sub-frame has significant effect in reduction of transmitted vibration to occupants. In order to optimize the sub-frame parameters, the sensitivity analysis is performed to derive effective parameters of sub-frame using DOE method. In this regard, the parameters which have dominant effect on transmitted vibration (the stiffness of sub-frame bushing in vertical direction) are optimized via RSM (Response Surface Method) method.
Technical Paper
2014-04-01
Sameer U. Kolte, David Neihguk, Abhinav Prasad, Samir Rawte, Aditya Gondhalekar
Abstract A typical powertrain mount design process starts with performing the system calculations to determine optimum mount parameters, viz. position, orientation and stiffness values to meet the desired NVH targets. Therefore, a 6 degrees of freedom lumped parameter system of powertrain and mounts is modelled in Matlab®. The approach is to decouple the torque roll axis mode from the remaining five rigid body modes so that the response to the torque pulses is predominantly ‘oscillations about Torque Roll Axis’. This is achieved by optimizing the above mount parameters within specified constraints so that ‘Rotation about the torque roll axis’ is one of the natural modes of vibration. The tool developed here uses ‘Particle Swarm Optimization(PSO) algorithm’ because of its ease of implementation and better convergence to the solution. The algorithm is programmed in TK solver®. Further, for the given torque input, the harmonic response of the powertrain mounted on optimized mounts, is evaluated for comparison with NVH targets.
Technical Paper
2014-04-01
Shigenori Ichinose, Kiyoshi Iwade, Yoshiharu Hata
Abstract The oil flow in the oil ring groove was observed in order to improve the oil ejection efficiency in the oil ring groove. The oil flow was visualized with a clear head piston using fluorescing agent and particles under motoring condition. The influences of oil ring specification on the direction and the velocity of the oil flow were evaluated. The velocity of the oil ring with oil vent holes was faster than that of the oil ring without oil vent holes. In the case of the oil ring with vent holes, the reverse flow of the oil toward the front side was observed in the back clearance. Therefore, oil vent holes can change the oil flow and improve the oil ejection efficiency in the oil ring groove.
Technical Paper
2014-04-01
Guenter Bischof, Karl Reisinger, Thomas Singraber, Andreas Summer
In this work, we investigate the rotor bearing loads of a flywheel-based KERS that are caused by dynamic forces and gyroscopic torques during representative driving maneuvers. Based on the governing equations of motion of a gyroscope, the equations for the rotor-platform interactions are developed. These equations, which relate the vehicle's roll, pitch and yaw rate with the internal transverse torques on the flywheel, are integrated into a commercial vehicle dynamics program. An average passenger car model equipped with a typical high-speed flywheel energy storage system is used for the numerical investigations. The flywheel bearing loads produced by some selected, representative driving maneuvers are simulated for different orientations of the flywheel spin axis relative to the body frame. In addition, the dynamic response of the vehicle to the reaction torques is investigated in open and closed-loop vehicle dynamics simulations. Thus, the steering response of a driver model to the gyrodynamics of a flywheel-based KERS is obtained for fully charged KERS as well as during braking and under acceleration boosts.
Technical Paper
2014-04-01
Christian Scheiblegger, Nantu Roy, Orlando Silva Parez, Andrew Hillis, Peter Pfeffer, Jos Darling
Abstract Cab mounts and suspension bushings are crucial for ride and handling characteristics and must be durable under highly variable loading. Such elastomeric bushings exhibit non-linear behavior, depending on excitation frequency, amplitude and the level of preload. To calculate realistic loads for durability analysis of cars and trucks multi-body simulation (MBS) software is used, but standard bushing models for MBS neglect the amplitude dependent characteristics of elastomers and therefore lead to a trade-off in simulation accuracy. On the other hand, some non-linear model approaches lack an easy to use parameter identification process or need too much input data from experiments. Others exhibit severe drawbacks in computing time, accuracy or even numerical stability under realistic transient or superimposed sinusoidal excitation. To improve bushing modeling of cab/box mounts for heavy duty/light duty trucks, a practical approach to model non-linear bushing dynamic characteristics has been tested and validated against standard bushing models.
Viewing 1 to 30 of 14852

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