METHOD FOR MAKING A SOUND REDUCING PANEL WITH RESISTIVE LAYER HAVING STRUCTURAL PROPERTY AND RESULTING PANEL

摘要

The invention concerns a method for making a sound reducing panel comprising an honeycomb core structure (2) flanked, on one side, by a reflector (3), and, on the other by an acoustically resistive layer (1') with two components having acoustic and structural property respectively. The invention is characterised in that it consists in: fixing on a mould having a shape suited for the panel to obtain a layer with structural property (1'a) consisting of yarns (7, 8) pre-impregnated with a thermoplastic or thermoset resin, by lay-up, winding or wrapping, such that said layer exhibit an open surface proportion of the order of 30 % of the whole exposed surface, and in fixing on the structural property layer a layer with acoustic property (1'b) consisting of a macroporous fabric having a thickness of the order of one-tenth of that of the structural property layer, then in fixing the open-cell structure (2) and the reflector (3) optionally with the addition of an adhesive (5, 6) between the components, at least a step of autoclave curing being carried out at the end of at least one of said fixing steps. The invention is particularly useful for making sound reducing panels for aircraft turbo engines.