An acoustically insulated machine including a source of noise positioned within a housing, a first insulation member positioned within the housing and including a first porous sound absorbing layer and a first dense layer, and a second insulation member positioned within the housing and including a second porous sound absorbing layer and a second dense layer. The first insulation member being is positioned closer to the internal source of noise than the second insulation member and the first insulation member being spaced apart from the second insulation member such that an air gap is formed between the first insulation member and the second insulation member.

An acoustically insulated machine including a source of noise positioned within a housing, a first insulation member positioned within the housing and including a first porous sound absorbing layer and a first dense layer, and a second insulation member positioned within the housing and including a second porous sound absorbing layer and a second dense layer. The first insulation member being is positioned closer to the internal source of noise than the second insulation member and the first insulation member being spaced apart from the second insulation member such that an air gap is formed between the first insulation member and the second insulation member.

Systems and methods are disclosed for a multi-layered sound absorption structure. The multi-layered sound absorption structure may include a form material, an acoustic material disposed on a surface of the form material, and a construction material disposed on the acoustic material. The acoustic material may couple to the construction material during curing of the construction material. After the construction material is cured, the form material may be removed exposing a least a portion of the acoustic material.

Systems and methods are disclosed for a multi-layered sound absorption structure. The multi-layered sound absorption structure may include a form material, an acoustic material disposed on a surface of the form material, and a construction material disposed on the acoustic material. The acoustic material may couple to the construction material during curing of the construction material. After the construction material is cured, the form material may be removed exposing a least a portion of the acoustic material.

An object of the present disclosure is to provide a composite material laminate excellent in impact resistance and vibration damping property. The present disclosure is a composite material laminate including a metal substrate, an adhesive layer formed on a surface of the metal substrate, and a foamed body layer formed on a surface of the adhesive layer, wherein a shear fracture strength (S) at an interface between the metal substrate and the adhesive layer is 1.0 MPa or more, and (S/F) determined by dividing the shear fracture strength (S) at the interface by a bending elastic modulus (F) of the foamed body layer is 0.007 or more and 0.5 or less.

The application relates to a nonwoven composite containing a plurality of solid regions and a plurality of porous regions. The solid and porous regions form a repeating pattern on the surface of the composite. The solid regions contain a solid region nonwoven layer, an optional solid region polymer-fiber infused layer, and a solid region cap layer. The solid region nonwoven layer contains a plurality of first staple fibers and less than about 5% by volume of a first polymer. The solid region cap layer contains the first polymer and less than about 5% by volume of the first staple fibers. The porous regions contain a porous region nonwoven layer and a porous region polymer-fiber infused layer. The porous region nonwoven layer contains a plurality of the first staple fibers and less than about 5% by volume of a first polymer. The porous region polymer-fiber infused layer contains a plurality of pores.

An apparatus is provided for an aircraft propulsion system. This apparatus includes an acoustic panel and a mount. The acoustic panel includes a perforated face skin, a back skin, a perforated intermediate layer, a first cellular core and a second cellular core. The first cellular core includes a first section and a second section. The first section is between and is connected to the perforated face skin and the perforated intermediate layer. The second section is between and is connected to the perforated face skin and the back skin. The second cellular core is between and is connected to the perforated intermediate layer and the back skin. The mount is attached to the back skin along the second section.

A sound absorption structure and a method of manufacturing the same are provided. The sound absorption structure includes a first sound absorption layer comprising first elements of which longitudinal directions are misaligned in a thickness direction of the sound absorption structure, the first sound absorption layer having a first internal filling density and absorbing sound waves of a first reactance frequency; and a second sound absorption layer disposed on the first sound absorption layer, having a second internal filling density different from the first internal filling density, and absorbing sound waves of a second reactance frequency different from the first reactance frequency.

A sound absorption structure and a method of manufacturing the same are provided. The sound absorption structure includes a first sound absorption layer comprising first elements of which longitudinal directions are misaligned in a thickness direction of the sound absorption structure, the first sound absorption layer having a first internal filling density and absorbing sound waves of a first reactance frequency; and a second sound absorption layer disposed on the first sound absorption layer, having a second internal filling density different from the first internal filling density, and absorbing sound waves of a second reactance frequency different from the first reactance frequency.

An assembly is provided for an aircraft structure. This aircraft structure assembly includes an acoustic panel and a thermal anti-icing system. The acoustic panel includes an exterior surface. The thermal anti-icing system includes a susceptor and a microwave system. The susceptor is configured with the acoustic panel. The microwave system is configured to direct microwaves to the susceptor for melting and/or preventing ice accumulation on the exterior surface.