Rolls-royce Corporation

Fabrizio Scarpa

Kenneth E Evans

Ramesh Rajasekaran

Matteo Bianchi

Chrisopher W Smith

Christopher W Smith

Marc-Antoine Boucher

Wayne Miller

Christopher Smith

Kenneth Evans

A method of manufacturing a foam having a Poisson's ratio which varies across at least a region of the foam in a gradient distribution involves the steps of: a) providing a housing defining an internal space having an inlet aperture and an outlet aperture; b) providing an open-cell foam of a size and shape configured to fit inside the internal space of the housing; c) positioning the foam inside the internal space of the housing; d) establishing a flow of air through the foam via the inlet and outlet apertures; e) heating the foam to a predetermined temperature while maintaining the flow of air through the foam; and f) subsequently cooling the foam while continuing to maintain the flow of air through the foam. A foam of such a type is also presented.

Method of manufacturing a foam showing a gradient poisson's ratio behaviour

A vibration damping insert configured to seat within a cell of a cellular structure and to span the cell cavity. The insert comprises a first portion formed of a first material and a second portion formed of a second material having lower stiffness than the first material. The first portion is arranged to constrain deformation of the second portion to be in a predetermined direction. The invention also comprises a vibration damping body comprising a cellular structure formed of a plurality of tessellating cells and a vibration damping insert as described. The vibration damping insert is mounted in at least one of the cells in the cellular structure. The invention also comprises a method of manufacturing a vibration damping body.

Vibration damping

A vibration damping body including an auxetic cellular structure having cell walls therein formed substantially of a first material having a first stiffness, the cellular structure further including a second material attached to said cell walls, the second material being selectively located throughout the cellular structure so as to include less than 50% by mass thereof and having a second stiffness which is lower than said first stiffness.

Vibration damping structures

A method of manufacturing a foam having a negative Poisson's ratio comprising the steps: placing a padof open cell polyurethane foam on a moulding surface; placing a flexible membraneover the exposed surface of the foam to create a sealed chamberbetween the moulding surfaceand the flexible membranein which the foam padis disposed; applying an isostatic pressure difference between the inside and the outside of the chamberthereby collapsing the foam padbetween the flexible membraneand the moulding surface; heating the foam padto a predetermined temperature, and subsequently cooling the foam padwhile collapsed.

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Bristol, United Kingdom

Fabrizio Scarpa