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Technical Paper

“Bump Test” of Wet Friction Materials: Modeling and Experiments

2001-03-05
2001-01-1154
In one of the fatigue tests for wet friction materials, “bump test”, an inertia-type rig equipped with a multi-disk assembly is used. One of the steel disks in the assembly has radial bumps for the purpose of creating high local contact pressure and high temperature. Due to the severe contact conditions, a comparative testing for different friction materials can be conducted within a relatively small number of cycles. In the paper, a design of a “bump” assembly used for automotive wet friction materials is described. Based on both experimental tests and advanced contact modeling, non-uniform contact pressure generated by the bumps and resulting temperature are estimated. The computational model is used then to study the influence of the modulus of elasticity of the friction material and reaction plate thickness on the contact conditions. The bump fatigue tests lead ultimately to material failure.
Technical Paper

‘Bigelow Aerospace® Life Support Laboratory - Planning and Status’

2004-07-19
2004-01-2474
This Life Support Laboratory consists of a simulator of the spacecraft called Nautilus, which houses Air Revitalization Subsystem, Atmospheric Control and Supply, and Fire Detection and Suppression in the Equipment Area. There are supporting facilities including a Human Metabolic Simulator, simulated Low and Moderate Temperature Coolant Loop, chemical analysis bench, purified water supply, vacuum and gas supplies. These facilities are scheduled to be completed and start to operate for demonstration purposes by March 2005. There are an ARES Ground Model (AGM) and a Trace Contaminant Control Assembly in the ARS. The latter will be integrated with the AGM and a Condensing Heat Exchanger. The unit of AGM is being engineered, built, and will be delivered in early 2005 by EADS Space Division. These assemblies will be operated for sensitivity analysis, integration and optimization studies. The main goal is the achievement for optimal recovery of oxygen.
Technical Paper

Zinc on the Move: Advancements in Coatings and Castings Keep the Metal Competitive

1986-02-01
860611
For over a decade, industry prognosticators have been predicting that the use of plastics by automakers would soon surpass the deployment of metals in automobiles, While there is no denying that plastics have made inroads, it recently has become apparent that metal will retain its position as the prime car material for the foreseeable future. One reason for the revised forecast is the development of improved zinc coatings for the automotive industry. Such material as electrogalvanized and Galfan™ are shaping up as steel's saviors when it comes to ensuring that metal will continue to play the major role on car assembly lines. Meanwhile on the other side of the equation, developments in zinc die casting technology have taken the edge off plastics' forward thrust into both functional and decorative car part applications.
Standard

Zinc Die Casting Alloys

2017-12-20
CURRENT
J469_201712
Because of the drastic chilling involved in die casting and the fact that the solid solubilities of both aluminum and copper in zinc change with temperature, these alloys are subject to some aging changes, one of which is a dimensional change. Both of the alloys undergo a slight shrinkage after casting, which at room temperature is about two-thirds complete in five weeks. It is possible to accelerate this shrinkage by a stabilizing anneal, after which no further changes occur. The recommended stabilizing anneal is 3 to 6 h at 100 °C (212 °F), or 5 to 10 h at 85 °C (185 °F), or 10 to 20 h at 70 °C (158 °F). The time in each case is measured from the time at which the castings reach the annealing temperature. The parts may be air cooled after annealing. Such a treatment will cause a shrinkage (0.0004 in per in) of about two-thirds of the total, and the remaining shrinkage will occur at room temperature during the subsequent few weeks.
Technical Paper

Zero Resistance Technology (ZRT)

2005-11-22
2005-01-4109
Delphi's Zero Resistance Technology (ZRT) is a revolutionary new product/process that enables the reduction of mass and volume from a traditional wiring assembly. ZRT is defined as a minimal (zero) resistance change over time. The ZRT product is an electrical/electronic connection system which provides a viable solution for high density and limited space wiring applications. The ZRT process is a semi-automated wiring harness manufacturing system with flexibility to produce harnesses to the customer demand.
Technical Paper

Zarya Energy Balance Analysis: The Effect of Spacecraft Shadowing on Solar Array Performance

1999-08-02
1999-01-2430
The first element of the International Space Station (ISS), Zarya, was funded by NASA and built by the Russian aerospace company Khrunichev State Research and Production Space Center (KhSC). NASA Glenn Research Center (GRC) and KhSC collaborated in performing analytical predictions of the on-orbit electrical performance of Zarya’s solar arrays. GRC assessed the pointing characteristics of and shadow patterns on Zarya’s solar arrays to determine the average solar energy incident on the arrays. KhSC used the incident energy results to determine Zarya’s electrical power generation capability and orbit-average power balance. The power balance analysis was performed over a range of solar beta angles and vehicle operational conditions. This analysis enabled identification of problems that could impact the power balance for specific flights during ISS assembly and was also used as the primary means of verifying that Zarya complied with electrical power requirements.
Standard

ZINC DIE CASTING ALLOYS

1989-01-01
HISTORICAL
J469_198901
Because of the drastic chilling involved in die casting and the fact that the solid solubilities of both aluminum and copper in zinc change with temperature, these alloys are subject to some aging changes, one of which is a dimensional change. Both of the alloys undergo a slight shrinkage after casting, which at room temperature is about two-thirds complete in five weeks. It is possible to accelerate this shrinkage by a stabilizing anneal, after which no further changes occur. The recommended stabilizing anneal is 3 to 6 h at 100 °C (212 °F), or 5 to 10 h at 85 °C (185 °F), or 10 to 20 h at 70 °C (158 °F). The time in each case is measured from the time at which the castings reach the annealing temperature. The parts may be air cooled after annealing. Such a treatment will cause a shrinkage (0.0004 in per in) of about two-thirds of the total, and the remaining shrinkage will occur at room temperature during the subsequent few weeks.
Technical Paper

Xtreme Make-Over In 24 Hours

2005-05-16
2005-01-2550
Our conference chairman told me that this special technical section was structured to provide “some words of wisdom from the old guys” or something to that effect. I know I can meet most of his requirements. I am a pensioner and an oak tree. However, “words of wisdom” maybe a challenge. Solving noise problems, setting acoustical performance targets and guidelines, and developing noise control systems for new and carry-over vehicles can be very challenging and time consuming particularly in today's culture. In the 1970's and 80's, and 90's we had the same challenges. Our customers demanded and appreciated a quiet vehicle. They want to talk to each other without shouting or to enjoy a favorite music selection regardless of weather, road conditions, or vehicle speed. The use of ear plugs or cotton is not acceptable! Noise Gremlins (Figure 1) can ruin a good day!
Technical Paper

X-38 Nose Skirt Panels - Results of Qualification Testing

2001-07-09
2001-01-2343
The X-38 vehicle will be used to demonstrate the future technology on durable TPS for the CRV. Astrium has produced two large CMC Nose Skirt side panels for the current X-38 configuration. The design of the 3 dimensional curved and large side panels comprises a light-weight, stringer stiffened concept which compensates the thermal expansion by a system of flexible metallic stand-offs. An optimum in flexibility and stiffness to fulfil all requirements had to be found: strong and stiff enough to carry the thermo-mechanical loads, but flexible enough to realise a fastening concept which does not fail due to thermal expansion. The fastening concept has been tested on development test level. Some thermal and mechanical tests on sub-structure level confirmed the design and analysis work of the complete TPS concept.
Standard

Wrenches, Twelve Spline, Metric

1989-11-01
CURRENT
MA1547A
This standard covers the design, performance, and test requirements for high strength, thin wall, commercial sockets, universal sockets, and box wrenches used for the attachment and detachment of metric spline drive, high strength, and high temperature aircraft fasteners. Inclusion of dimensional data in this standard is not intended to imply that all of the products described herein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes. This standard is based on, but not limited to, the following external spline wrenching system:
Standard

Wrenches, Box and Open End Combination Twelve Point, High Strength, Thin Wall, Metric

2013-02-10
CURRENT
MA4535A
This SAE Metric Aerospace Standard (MA) provides dimensional, performance, testing and other requirements for high strength, thin wall, double head box and combination wrenches which possess an internal wrenching design so configured that, when mated with hexagon (6 point) fasteners, they shall transmit torque to the fastener without bearing on the apex of the fastener’s wrenching points. This standard provides additional requirements beyond ANSI B107.9 appropriate for aerospace use. Inclusion of dimensional data in this document is not intended to imply all of the products described therein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes.
Technical Paper

Worldwide Status of Leadless Component Assembly Technology

1982-02-01
820916
The wide variety of available leadless electronic components is described. Some typical applications of these devices are illustrated. The advantages to be gained through the use of these surface mounted devices are explained. These include reduced size, increased reliability, improved performance and reduced cost. Methods of application, including automatic assembly equipment, are discussed. Several applicable soldering processes are explained.
Technical Paper

World Trucks - A European View

1989-08-01
891630
The idea of a world truck is a fascinating challenge - whereas cars are purchased more or less as seen; truck purchasers demand more individual configurations. In national and global terms, that means a highly complex truck market. Historically, a few European and North American manufacturers produced almost all the trucks for the world market. That changed through the 60's and 70's, with more local assembly plants around the world and increasing worldwide manufacturing capabilities. Concurrently, international component design standards have made some progress towards compatibility. Much greater co-operation is needed, however, before a genuinely international set of standards can be applied. As the task assigned to trucks is the same worldwide, namely to transport goods from A to B; it should be desirable and possible to work towards a greater commonality of vehicle - to ultimately achieve a world truck. The only unknown is the time scale.
Standard

Wiring, Positioning, and Support Accessories

2015-10-01
CURRENT
AS23190C
AS23190 is a procurement specification that covers a series of plastic and metal components and devices used for the tying, positioning, and supporting cable, cable assemblies, wire, and wire bundles in electrical, electronic and communication equipment, and in interconnection systems.
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