Showing papers on "Sandwich panel published in 1987"

Sandwich panel fastener

Abstract: A fastener designed to be securerd into a hole in an aircraft panel can be manufactured from an integral engineering thermoplastic structure which includes a centrally located cylindrical body carrying flanges at its ends. One of these flanges has diametrically opposed notches leading through it. Ribs are located on the flanges so that when the fastener is within a hole in a panel and a fluid resin composition is forced in to one of the notches the flow is divided into two separate streams, each of which flows in a labyrinth-like manner in reaching the other notch.

Sandwich panel assembly

Abstract: A sandwich panel assembly for refrigerated and non-refrigerated structures has an insulating layer disposed between two facings. A chain having hooks or a wire is attached to the facings and is entirely embedded in the insulating layer for positively connecting the faces together. Cable or strapping may be used in place of the connecting or wire. A thermal insulation prevents thermal short circuits from a facing through the chain or wire.

Fold and bond for constructing cement laminate structural shapes

Abstract: An article formed by stiffening the folds of the folded plate structure by applying a low viscosity penetrant along the folds which reacts with the cement to harden it where it has been weakened due to folding. Applications include sandwich panel roof and floor decking and siding for buildings, cylindrical sandwich panels for arch roofs and large pipes or culverts, box beams and girders, and dome roofs.

Sandwich panel and connection profile therefor

Abstract: A sandwich panel in which a connection profile 21 is provided on at least one edge and co-operates with a tongue 15 on the edge of an adjacent panel. The sandwich panel itself is filled with an insulating material, such as foam, and has on opposite faces metal sheets 12, 13, 18, 19. A connection profile 21 includes a web 22, first and second edge flanges 23 and 24, and third and fourth flanges 29 and 32 therebetween. The fourth flange extends into a recess 33 in the tongue and is spaced from the first flange sufficiently to accommodate a part of the tongue as well as the clamping portion 30 of a clamp 31 which holds the panels against a support member 35.

Design, fabrication and properties of composites with multi-layered and 3-d glass fabric reinforcement.

Abstract: Laminated composites have excellent properties in the fibre directions but are vulnerable to loads which induce inter-laminar shear failure. A three-dimensional arrangement of fibres should greatly improve the ability of composites to withstand such loads. Textile technology has been used to weave a range of single-and multi-layer fabrics for fibre reinforcement of epoxy resins. The multi-layer fabrics are produced with and without integral yarn stitches which interact between the fabric layers and are incorporated in the weave design. An important feature of this work is that standard power looms are used to produce the multi-layer fabrics and thus such weaves have great commercial potential. The paper describes the structure of 2, 4 and 8 layer plain and satin weaves and the development of methods for vacuum impregnation of these glass fabrics with epoxy resin. The impregnated product has a low void content and mechanical properties are evaluated by tensile and inter-laminar shear tests. The mechanical properties of composites with and without integral cross-linking yarns are compared in relation to the weave structure. Cellular three-dimensional reinforcements, again woven in a single step, are also described, which have wide potential as structural sandwich panel cores.

Rectangular hybrid elements for the analysis of sandwich plate structures

Abstract: The structural bchaviour of sandwich plate structures are characterized by transverse shear dcformations in the core. The assumed stress hybrid finite elemcnt technique is particularly suitable for developing sandwich plate bending elements. In the present study, rcctangular three-layer sandwich plate clements have bcen formulated using simple assumed stress functions. Numerical test problems have been solved to examine the convergence property and suitability of these clcments. The results are compared with that of a complete quadratic strcss mode element and with analytical solutions. Six degrees of freedom per node shell elements are formulated by combining the plate bending elcmcnts with mcmbrane elements. A folded plate sandwich panel roof has bcen analyzed using these elements and the results arc compared with the experimental values. The use of simple strcss function gives satisfactory results and reduces the size of the matriccs to be uscd, the length of the program, and the computation time for the formulation of clement stiffness matriccs.

Composite material of self supporting sandwich panel type

Abstract: 1. Composite material of the prefabricated self-supporting sandwich panel type, consisting of an insulating core made of polyurethane or polyisocyanurate foam situated between a rigid sheet and an optionally reinforced, bitumen-based sealing coat sheet, characterized in that it comprises a layer of fibrous material between the sealing coat sheet and the foam insulating core.

Tensile Shear Creep Test of Steel-Balsa-Steel Sandwich Panel as Floor Deck (I) : Stress Distribution and Deformation of Specimen

Abstract: .-Stress analysis by finite element method of tensile shear test specimens of steel-balsa-steel· sandwich panel for creep test was made statically. The stress distribution of five different shapes of sandwich panel specimens, two of them in accordance ~ith ASTM-C-273, wef(~ analysed through the calculation of normal stress (O'Y), maximum principal stress (0'1), shear stress (TXY) and principal shear stress (Tmax). The presence of stress singularities at the reentrant corners made by specimen· and loading plates suggests fracture occurance in balsa core near the corner. Stress intensity factors (KA) in balsa core near the corner. were calculated under assumption of similarity with that in homogeneous body. The results. obtained were as follows: 1) O'Y, 0'1 and Tmax of balsa core concentrated near the reentrant corners, and TXY distribution was uniform throughout the balsa core, 2) Comparing KA of various specimens it was suggested that the estimated fracture load on specimens shaped within the range specified by ASTM standard (length l/thickness t>12) did not vary. Fracture load of specimens with l/t=8.2, 6.3 and 4.2 were lower than those of the standard specimens. Therefore, the standard shape will be utilized in the further investigation: tensile shear creep test of sandwich panel as floor deck (II).

Pole plate panel for high prequency heating pressing device

Abstract: PURPOSE:To facilitate the setting of a panel at processing and at the same time prevent a metal plate from deforming in case that the applying voltage at processing is high by a consititution wherein a sandwich panel, which is produced by affixing metal plates functioning as pole plate to a core material consisting of honeycomb core having electrical insulating characterisitics, is employed as each of pole plate panels. CONSTITUTION:Each of pole plate panels 1 and 1 consists of a honeycomb core 2 made of core material, which is composed of stock having an electrical insulating characteristic and has enough compressive strength to withstand the pressure to pressurize a workpiece A and at the same time which is formed so as to have a thickness capable of obtaining enough electrical insulating property to the voltage applied at the processing of the workpiece A and has excellent flatness, and metal plates 3 and 4 affixed onto both the sides of the honeycomb core 2. The size of the pole plate panel 1 is made to be larger than that of the workpiece A. Consequently, when the processing of the workpiece A under heat and pressure with a high frequency heating pressing device 10 by using the pole plate panels 1 and 1 is intended, the setting and the like of the panels at processing is easy. In addition, even when the applied voltage at processing by the pole plate panels is high, no deformation develops in the metal plates and consequently the excellent durability of the pole plate panel results.

Tensile Shear Creep Test of Steel-Balsa-Steel Sandwich Panel as Floor Deck (II) : Development of Simple Shear Creep Test Machine

Abstract: -A simple shear creep test machine was proposed and creep test was made with ASTM standard shape specimens. Also comparative measuring method of shear deformation was discussed. The results obtained were as follows: 1) The test machine made as a prototype for tensile shear creep test was capable to transmit more than 1,300 kgf to the specimens so it would be suitable for test about 69% of shear strength (Pmax = 1,896 kgf), 2) The measuring method of shear deformation, which had the measurement points mounted on brass tips placed on loading plates edge. can be considered practical. Although the glue-line deformation between specimen and loading plates tested have been neglected. Prototype with accuracy and lower costs was achieved. Therefore, it is possible to extend the creep test period or to make simultaneous tests on many specimens when constructing several test machine.

Pretreatment for painting of sandwich panel

Abstract: PURPOSE:To execute a pretreatment of a sandwich panel with good painting adhesiveness by subjecting the surfaces of face plates to an acid etching treatment, protecting the surfaces with masking tapes, fixing the face plates to the top and bottom surfaces of a honeycomb core, stripping the tapes and executing painting CONSTITUTION:The face plates 2a, 2b of the honeycomb core 1 are immersed in a liquid chemical and are subjected to the acid etching treatment in the pretreatment at the stage of subjecting the face plates having the sandwich adhered structure to surface painting The masking tapes 4 are stuck to the painting surface X side of the face plates 2a, 2b to protect the surfaces so as to avoid staining the treating surfaces An adhesive agent 3 is then stuck to the side opposite from the painting surface X side and the face plates 2a, 2b are adhered to the top and bottom surfaces of the honeycomb core 1; at the same time, the adhesive agent is cured by heating The masking tapes 4 on the painting surface X side are stripped and the painting surfaces of the face plates 2a, 2b are painted The treatment before painting is thus executed with good efficiency and the painting adhesiveness of the sandwich panel is improved

Stiffness of Profiled Sandwich Panel Roof Cladding

Abstract: This paper deals with a study which was made of the load‐deflection relationships of profiled sandwich panel roof cladding. A series of measurements were made on the cladding loaded by air bags to give a uniform pressure. A theoretical method based on the observed deflection characteristics of the cladding is suggested, which makes it possible to calculate the flexural stiffness and deflection of the cladding in a reasonably simple way. The observed deflection pattern is described together with the results of the tests and the predictions of the theoretical method. A reasonable agreement is demonstrated between the measured and predicted results.

Method of manufacturing a sandwich panel

Abstract: A method of manufacturing a sandwich panel in which two rigid or semi-rigid skins are mounted in spaced, substantially parallel vertical relation with the panel edge members extending across the gap between the low edges of the skins. At least one nozzle is introduced between the upper edges of skins and a liquid foam forming material is projected laterally against the inner services of the skins, adjacent the upper edges thereof, and the liquid is allowed to flow downwardly to wet substantially the entire inner surface of each of the skins. The introduction of the liquid is continued until sufficient foam forming material has been introduced into the space between the skins to obtain the desired foam interior under the prevailing conditions. The gap between the upper edges of the skins is closed and the foam is allowed to expand and fill the space between the skins and thereafter to cure.