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This SAE Aerospace Recommended Practice (ARP) describes standard methods for restoring damaged core on commercial aircraft sandwich structures. The methods shall only be used when specified in an approved repair procedure or with the agreement of the Original Equipment Manufacturer (OEM) or regulatory authority. The repair materials shall be defined in the approved repairs referencing these methods.

Abstract The article considers one of the possible mechanisms of loading the solidity of a cylindrical metal composite high-pressure vessel (MC HPV). This mechanism manifests itself as delamination of a thin-walled metal shell (liner) from a more rigid composite shell causing local buckling. ...This mechanism manifests itself as delamination of a thin-walled metal shell (liner) from a more rigid composite shell causing local buckling. A similar effect can be detected in the manufacturing process of MC HPV, when the composite shell is formed by winding with tension a carbon fiber-reinforced plastic tape on the liner. ...A similar effect can be detected in the manufacturing process of MC HPV, when the composite shell is formed by winding with tension a carbon fiber-reinforced plastic tape on the liner.

A complete formulation of the elasticity boundary value problem is developed and appropriate boundary conditions are employed at the inner and outer radii of the composite sphere to solve the displacement differential equation. Numerical values are estimated for the bottle displacement, volumetric strain, and three-dimensional stresses at the critical locations. ...Results indicate that Kevlar/epoxy and carbon/epoxy composite vessels will save weight and have the high performance of metal tankage.

A local small-thickness gap between the liner and the composite shell is taken as a technological deviation so that the liner and the composite shell have a regular geometric shape without initial imperfections. ...Abstract This article presents a numerical solution to the problem of delamination in a separable Metal Composite High-Pressure Vessel (MC HPV). This problem is associated with local buckling of the inner metal shell (liner) surrounded by an outer rigid composite shell. ...This problem is associated with local buckling of the inner metal shell (liner) surrounded by an outer rigid composite shell. A geometrically and physically nonlinear MC HPV deformation model is constructed considering the three-dimensional stress-strain state, real-time mode, and technological deviations inherent in real vessel designs.

In this study, a new hydrophilic, composite membrane has been developed for passage of the coolant fluid and retention of gas bubbles. ...The resulting composite membranes have shown repeatable decrease in nitrogen permeability, which is indicative of a decrease in membrane pore size.

Due to the conventional autoclaving of pre-impregnated materials causes high costs in the production of carbon fibre structures, new injection methods have become more and more relevant. The research project “CFK-Tex” focuses on the automated handling and processing of preforms out of dry carbon fibre textiles. Regarding the advantages in quality improvement and process time, an automation of all process steps is getting enforced. The major challenge, in addition to the difficult handling-properties of the materials and high quality demands, is the enormous variety of outline variants caused by small production quantities but many different textile cuts per part. In the first step the requirements of an automated system are exactly analyzed considering the specific material properties as well as process and product based characteristics.

Nowadays LHP (CPL) is widely used in thermal control systems for space and ground applications. Wick structure is a key element which plays at least two roles: capillary pump to move a working fluid from condenser to the heat loaded zone and thermal and hydraulic breaker between liquid and vapor in LHP (CPL). This paper is devoted to the R&D of LHP with advanced low-cost ceramic wick structure, which has a high capillary pressure head and low thermal conductivity. First set of tests with acetone as a working fluid was done in Porous Media Laboratory, Minsk, Belarus to prove the possibility to use such kind of wick in present and future designs of LHP (CPL).

This Aerospace Recommended Practice (ARP) describes methods of vacuum bagging, a process used to apply pressure in adhesive bonding and heat curing of thermosetting epoxy and polyester matrix fabrications for commercial aircraft composite parts. If this document is used for the vacuum bagging of other than thermosetting epoxy and polyester materials, the fitness for this purpose must be determined by the user.

This SAE Aerospace Recommended Practice (ARP) describes standard methods for restoring damaged core on commercial aircraft sandwich structures. It currently applies to wet lay up repairs only. The methods shall only be used when specified in an approved repair procedure or with the agreement of the Original Equipment Manufacturer (OEM) or regulatory authority. The repair materials shall be defined in the approved repairs referencing these methods.

This document describes the materials, equipment, and processing techniques used in fabricating high-strength or high-modulus graphite-fiber-reinforced polysulfone laminates for structural applications for service up to 120°C (250°F).

This document describes the materials, equipment, and processing techniques used in fabricating high-strength or high-modulus carbon-fiber-reinforced polysulfone laminates for structural applications for service up to 120°C (250°F).

This recommended practice describes the materials, related equipment, and particular processing techniques utilized in process science curing of composite hardware where pressure is imparted specifically to the resin of curing composites. Included as Appendix "A" to this ARP is a discussion of the particular techniques developed for a processing science philosophy which has consistently produced void and porosity-free, large area, thick composite structures. ...Included as Appendix "A" to this ARP is a discussion of the particular techniques developed for a processing science philosophy which has consistently produced void and porosity-free, large area, thick composite structures.

A multi-axial dynamic test instrument was designed to perform wear testing of actual aircraft tires as well as tread/carcass composite specimens under laboratory loading conditions which simulate the elements of take-off, landing and taxiing operations. ...The wear tester consists of a self-spinning abrading head, mounted on the actuator of a servo-hydraulic test system, which faces either (1) the tread surface of a composite specimen clamped by a horizontal stretch frame or (2) the tread region of actual inflated tires. ...The test concept has been partially proven in the case of tread/carcass composite specimens by building a proto-type test apparatus and operating it successfully. In the current test set-up, the specimen is subjected to static tension to simulate a circumferential load in the tire footprint and the tread surface is in periodic contact with an abrading head under a specific level of pressure.

One of the key elements of a recently proposed composite porous media condensing heat exchanger for space systems is to utilize capillary pressure for collecting and removing water from the condensing unit. ...Experiments were conducted with a composite porous system comprised of porous graphite block and porous ceramic tubes. It was demonstrated that the liquid phase could be preferentially separated from the unsaturated porous graphite block as proposed. ...A flow model was also presented for predicting the phase separation by the composite porous system.

A new chromium carbide/nichrome composite powder has been developed. Unlike the commonly used powder blends, each carbide is clad with a layer of nichrome. ...Results show that air sprayed coatings from the composite powder have 3 times more abrasive wear resistance than the conventional blend and the abrasive Wear resistance of the low pressure sprayed coatings is 4 times that of the blend.

The central displacement and the applied pressure were recorded and used with simple beam theory to calculate the dynamic modulus of elasticity and the dynamic yield strength in compression of the Kevlar composite.

For reporting purposes, the airplane variables of wheel load, wheel spacing, and tire pressure, and the pavement variables of type (rigid, flexible, or composite), and subgrade strength characterization (strong, medium, low, and extra low strength) are related by means of two theoretical stress/deflection distributions: Westergaard for rigid pavements and modified Boussinesq for flexible pavements.

Many test conditions are reduced to a few composite variable coefficients which may easily be used for further aircraft design conditions for strength or fatigue.

The WEB is a thermal isolating composite structure with co-cured thermal control surfaces and an ultralightweight hydrophobic solid silica aerogel which minimizes conduction and radiation.

Initial comparisons of centralized power generation and distribution are drawn against the design concept of a composite system. The importance of hydraulic power in control of the S. S. T. is discussed and a recommendation presented for earlier attention to the hydraulics area by the ultimate operators of the S.