Browse Topic: Insulation
The intent of the SAE Aerospace Recommended Practice (ARP) is to provide a process for users to identify the part number of AS7928 terminal lugs installed in civilian or military applications, although it can also be used to identify terminals that have been stored incorrectly. This ARP is subject to change to keep pace with experience and technical advances of AS7928 terminals. A current set of tables are provided to list and identify current AS7928 terminal lug configurations per the associated specification detail sheet and terminal lug configuration. Specific configuration details, graphic, size, and marking information for each individual terminal lug is provided to assist the product user with accurate selection for replacement or identification.
Plastic materials are used for a wide variety of spacecraft applications including seals, bearings, fasteners, electrical insulators, thermal isolators, and radomes. Selecting plastics for use in space is complex due to wide operating temperature ranges, vacuum conditions, and exposure to radiation and atomic oxygen. Additionally, some spacecraft applications require sealing flammable propellants such as hydrogen and oxygen. This article will present some design considerations when selecting plastics for use in spacecraft. It will provide rich data on the performance characteristics of plastics as well as examples of successful spacecraft applications.
The interaction of electric, electronic (E/E) and mechanical components defines the quality of a BEV’s powertrain. Component selection, their integration and calibration aim at meeting legal requirements for EMC and safety as well as competitive targets for efficiency, NVH and driving comfort. These tasks in particular need attention on electromagnetic events on the DC bus, the high-power electronics of inverters, the e-motors, and the drive shaft. Each component within this environment is defined by its electromechanical features with variabilities selected from a large set of operating parameters. Consequently, a complete powertrain and its controllers give rise to endless combinations for powertrain operation. How to understand and avoid risk laden and ineffective parameter options, how to find powertrain control parameters for safe, efficient and comfortable operation? And how to find solutions within competitive development timeframes? Particular issues include high voltage risks
The desert landscapes of the western United States have changed since Mr. Duke and Dr. Gonzo blazed a trail across them in a drug-infused haze. But their advice to buy the ticket and take the ride is still a wise mantra - especially in the serene comfort of a modern full-size pickup. As inhospitable as southern Nevada can be outside Sin City, the amenities within the climate-controlled and leather-lined cabin of the latest Ram pickups insulate you from those realities. SAE Media was invited to sample the latest heavy haulers in Ram's portfolio, including the new 2500 and 3500 models with the high-output version of the Cummins B6.7 diesel.
This article follows a companion article [1] presented at the SAE NVC 2021, in which a new system for the measurement on small samples of the normal-incidence Insertion Loss (IL) of multilayers used for the manufacturing of automotive sound package parts was first introduced. In addition to simplifying the evaluation of the sound-insulation of multi-layers used to produce sound-package components, the system aims at overcoming the limitations of the test procedure based on the ASTM E2611 standard. In this article, the latter point is demonstrated by comparing the insertion loss results obtained with the new system with those obtained with the test procedure based on the ASTM E2611 standard on a few multilayers commonly used for the manufacturing of automotive sound package parts. Results indicate that the data obtained by means of the newly developed system are more meaningful, practically usable and less prone to edge-effects, compared to those obtained according to the ASTM E2611
Researchers have demonstrated the ability to engineer materials that are both stiff and capable of insulating against heat. This combination of properties is extremely unusual and holds promise for a range of applications, such as the development of new thermal insulation coatings for electronic devices.
This SAE Aerospace Recommended Practice (ARP) describes the etching of fluoropolymer electrical wire insulations to ensure that all facets of the process from the chemistry to the processing, to the storage and handling are well defined.
Wire and cable products progress through a series of handling or operational steps from the time they leave the manufacturer, and until a finished harness or assembly is ready for installation on a vehicle. Throughout these many steps, environmental or processing conditions may be present which can generate damage detrimental to the wire or cable and/or its intended application.
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water
Hood insulators are widely used in automotive industry to improve noise insulation, pedestrian impact protection and to provide aesthetic appeal. They are attached below the hood panel and are often complex in shape and size. Pedestrian head impacts are highly dynamic events with a compressive strain rate experienced by the insulator exceeding 300/s. The energy generated by the impact is partly absorbed by the hood insulators thus reducing the head injury to the pedestrian. During this process, the insulator experiences multi-axial stress states. The insulators are usually made of soft multi-layered materials, such as polyurethane or fiberglass, and have a thin scrim layer on either side. These materials are foamed to their nominal thickness and are compression molded to take the required shape of the hood. During this process they undergo thickness reduction, thereby increasing their density. Hence, the material properties vary greatly based on the thickness and strain rate
Focused on the permanent magnet synchronous motor (PMSM) used in electric, this paper proposes an online insulation testing method based on voltage injection under high-temperature and high-humidity conditions. The effect of constant humidity and temperature on the insulation performance has been also studied. Firstly, the high-voltage insulation structure and principle of PMSM are analyzed, while an electrical insulation testing method considered constant humidity and temperature is proposed. Finally, a temperature and humidity experimental cycling test is carried out on a certain prototype PMSM, taking heat conduction and radiation models, water vapor, and partial discharge into account. The results show that the electrical insulation performance of the motor under constant humidity and temperature operation environment exhibits a decreasing trend. This study can provide theoretical and practical references for the reliable durability design of PMSM.
This research looks at the acoustic and mechanical characteristics of polypropylene (PP) composites supplemented with natural fibers to determine whether they are appropriate for automotive use. To generate composites that are hybrids, four diverse natural fibers, including Calotropis gigantea (CGF), jute, sisal, and kenaf, were mixed into PP matrices. The study examines how fiber type, frequency, and thickness affect sound absorption and mechanical strength. The results show that these natural fiber-reinforced composites have improved mechanical characteristics, with CGF (73.26 shore D value of Hardness), sisal (42.35 MPa tensile) and jute fibers showing particularly promising materials. Furthermore, the acoustic study emphasizes these materials’ frequency-dependent sound absorption properties, with particular efficacy in mid-frequency regions. Such organic reinforcement fiber materials’ acoustic performance is tested at 5 mm and 10 mm thicknesses. When a 5 mm thick sample is examined
This specification establishes the requirements for various types and colors of electrical insulating sleeving that will shrink to a predetermined size upon the application of heat. This specification includes provisions for demonstrating compliance with qualification requirements (see Section 4 and 7.3), in process inspection, and statistical process control inspections (see 4.4). The continuous operating temperature ranges for the sleeving classes covered by this specification are from -112 to +482 °F (-80 to +250 °C). The continuous operating temperature range for each sleeving class is given in the applicable detail specification.
This SAE Standard presents a test procedure for determining the airborne sound insulation performance of materials and composite layers of materials commonly found in mobility, industrial, and commercial products under conditions of representative size and sound incidence so as to allow better correlation with in-use sound insulator performance. The frequency range of interest is typically 100 to 10000 Hz 1/3-octave band center frequencies. This test method is designed for testing flat samples with uniform cross section, although in some applications the methodology can be extended to evaluate formed parts, pass-throughs, or other assemblies to determine their acoustical properties. For non-flat parts or assemblies where transmitted sound varies strongly across the test sample surface, a more appropriate methodology would be ASTM E90 (with a reverberant receiving chamber) or ASTM E2249 (intensity method with an anechoic or hemi-anechoic receiving chamber).
Partial discharge (PD) detection has been always a fundamental tool, potentially, for the design, quality control, commissioning, and reliability monitoring for the of insulation systems. The word “potentially” stems from the objective consideration of the intrinsic limitations suffered by the existing partial discharge, PD, measurement technologies, especially the need of experts to interpret results and the lack of clear correlation between PD-related quantities, and the condition-based maintenance approach. On the whole, a thorough revision of insulation systems design procedures and of the tools to evaluate aging and failure risk is needed, especially in components of electrical assets which are critical in terms of reliability, resilience, and safety. This paper focuses on critical asset components, such as ships, aircrafts, aerospace, and any type of vehicles, where the coming electrification is significantly increasing nominal voltage, power density and efficiency, and where
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