Showing papers on "Sandwich panel published in 1986"

Noise reduction nacelle

Abstract: A noise reduction nacelle for a jet engine having an inlet duct, a center body and at least one exit duct and which includes a composite sandwich panel positioned in the inlet duct, the center body and the at least one exit duct. The panel includes an inner face sheet, a honey comb core and an outer face sheet wherein the inner face sheet and the outer face sheet are connected to the inner and outer surfaces, of the core. A plurality of perforations are provided in the inner face sheet of a predetermined density and wherein each of the perforations is of a predetermined diameter. A method of forming the composite sandwich panel is also provided.

Transmission loss optimization in acoustic sandwich panels

Abstract: Considering the sound transmission loss (TL) of a sandwich panel as the single objective, different optimization techniques are examined and a sophisticated computer program is used to find the optimum TL. Also, for one of the possible case studies such as core optimization, closed‐form expressions are given between TL and the core‐design variables for different sets of skins. The significance of these functional relationships lies in the fact that the panel designer can bypass the necessity of using a sophisticated software package in order to assess explicitly the dependence of the TL on core thickness and density.

Critical shear loading of curved sandwich panels faced with fiber-reinforced plastic

Abstract: The force-displacement relations of a cylindrical!} curved anisotropic sandwich panel faced with fiberreinforced plastic (FRP) are derived by the complementary energy principle. The Rayleigh-Ritz method is then used for the buckling analysis of simply supported panels. The results show that 1) the quantitative difference between positive and negative shear buckling loadings; 2) panels of small aspect ratio are efficient to carry negative shear loads and those of large aspect ratio to carry marginally higher positive shear loads; 3) a fiber orientation angle of 50 deg measured from the curved edge provides maximum shear buckling strength; and 4) deeply curved shells resist higher negative shear loads and shallow shells higher positive shear loads.

Heat pipe embedded type sandwich panel

Abstract: PURPOSE:To make uniform the temperature distribution on the full surface of the panel and to lighten the weight of the panel by providing in parallel a plurality of branched type heat pipes each having a horizontal heat pipe at a suitable portion of a straight heat pipe. CONSTITUTION:Respective branched type heat pipes 6 are formed by connecting a plurality of straight heat pipes 1 to each other by means of cross type heat pipe joints 7. Therefore, horizontal parts of the heat pipe joints 7 of the adjacent branch type heat pipes 6 are successively superimposed on each other so as perform the role or horizontal heat pipes. Therefore, it is possible to make uniform the temperature distribution of the full surface of the panel 31. Further, in the heat pipe joints 7 and the straight pipes 1, there is produced no deterioration in the thermal characteristic due to damage of wicks in the inner parts of the pipes accompanied by the bending work. Still further, the weight of the horizontal part of each heat pipe joint 7 affords a sufficient contact area, and the panel weight can be reduced inspite of the sufficient performance.

High capacity demonstration of honeycomb panel heat pipes

Abstract: The feasibility of performance enhancing the sandwich panel heat pipe was investigated for moderate temperature range heat rejection radiators on future-high-power spacecraft. The hardware development program consisted of performance prediction modeling, fabrication, ground test, and data correlation. Using available sandwich panel materials, a series of subscale test panels were augumented with high-capacity sideflow and temperature control variable conductance features, and test evaluated for correlation with performance prediction codes. Using the correlated prediction model, a 50-kW full size radiator was defined using methanol working fluid and closely spaced sideflows. A new concept called the hybrid radiator individually optimizes heat pipe components. A 2.44-m long hybrid test vehicle demonstrated proof-of-principle performance.

Wheel and bicycle using it

Abstract: PURPOSE: To ruduce the weight of a wheel and enhance its strength, by laminating the surface material made of fiber reinforced thermosetting resin on both sides of an opening in a honeycomb structure, thereby supporting a rim by a sandwich panel buckled on its contact surface with the surface material of the honeycomb structure. CONSTITUTION: A rough fabric 2 is disposed on both sides of a honeycomb core 1 made of Aramid paper, and a prepreg 3 reinforced with a carbon fiber fabric on the surface thereof, and further a transparent Tedra film 4 on the outermost side thereof and press-formed so as to form a sandwich panel 7. Then a rim 6 and a wheel 8 are attached to the sandwich panel 7 so as to assemble the wheel. With this arrangement, it is possible to reduce the weight of the wheel and enhance its strength. COPYRIGHT: (C)1987,JPO&Japio

Creep properties of CF/GF hybrid laminates.

Abstract: This paper deals with the creep properties of CF/GF hybrid laminates. Hybrid laminates used in this experiment were symmetrical hybrid FRP laminates of 7 selected thickness ratio including CFRP and GFRP. The reinforcement used in CFRP was plain woven carbon-fibrous cloth.The conditions of the 3 points bending creep tests were 1 level of maximum bending stress at 5kgf/mm2, 4 levels of environmental temperature at 20°C, 50°C, 80°C and 110°C, 4 levels of off-axis angles at 0°, 15°, 30° and 45°, and 7 levels of thickness ratio [thickness of (sureface=CFRP)/Thickness of (total=CFRP+GFRP)] at 1, 0.5, 0.43, 0.33, 0.2, 0.09 and 0, respectively.The measured creep relaxation properties of these laminates were discussed on the basis of calculating formula of stiffness of sandwich panel and off-axis analysis of bi-directional reinforced theory. From the discussion, it is concluded that some of the selected hybrid laminates can be used as the advanced structural FRP materials for machine tools.

‘Fiberlam’ Aircraft Flooring

Abstract: Fibrelam is manufactured as flat board for fabrication by the end user - usually the airlines Originally designed as flooring for the wide-bodied ‘Jumbo Jets’ it is now used as new and replacement flooring in most other leading aircraft