Airbus Operations (s.a.s.)

Airbus France

Stephane Bianco

Marc Sartor

Christian Godenzi

Nicolas Dantou

Laurent Pinto

Romain Canivenc

A method for assembling a part of a metal material and a part of a composite material, the junction of the two parts being achieved through a fastener having a substantially constant section and received in a first hole formed in the part of a metal material and a second hole formed in the part of a composite material. According to the disclosed embodiments and before assembling the aforementioned parts, the method includes: an expansion step for generating a field of compression stresses at the periphery of the first hole and locally in the material constituting the part of a metal material using an expansion tool; a single boring step for making the first hole and the second hole with a diameter &#xd8;substantially larger than the diameter of the fastener in order to leave a gap between the inner walls of the holes and the outer surface of the fastener; and an assembling step for placing the fastener inside the holes for maintaining together the metal part and the composite part.

Method for assembling a part of a metal material and a part of a composite material using a fastener

Process for assembling a first part made of metal material and a second part made of composite material, by an attachment element, which includes: &#x2014;pre-piercing the parts to form a recess with a diameter Din the first and the second parts; &#x2014;installing an insert having a variable diameter in the direction of the thickness of the parts in the recess, the insert including a main hollow body and at least one flange designed to rest at least partially against the outside surface of a part, the insert being designed to accommodate the attachment element; generating residual compression constraints by radial expansion on the inner wall of the insert by an expansion tool having an outside diameter that works with the inside diameter of the insert in at least one zone of the two parts along the circumference of the insert; &#x2014;boring the recess of the main body wider so that the insert has a final inside diameter that is significantly greater than the outside diameter of the attachment element to allow play between the inner wall of the insert and the outside surface of the attachment element; and &#x2014;positioning the attachment element in the insert to keep the parts together.

Method for assembling a piece of metal material to a piece of composite material

A method, system, and computer program product for calculating the residual stress equilibrium of two elastoplastic cylinders coldworked by expansion to obtain interference fit. The deformation state due to an internal expansion load applied to an inner cylinder that will result in interference of the inner cylinder with the outer cylinder can be calculated. The deformation state due to an unloading of the internal expansion load that will result in assembly of the inner cylinder and the outer cylinder can be calculated. The residual stresses, residual displacement and residual strains in the inner cylinder and the outer cylinder, whether they are eventually interference fitted or not, can all be calculated and recorded.

Method, System, and computer program product for calculating the residual stress equilibrium of two concentric cylinders coldworked by a loading-unloading expansion process

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Toulouse, France

Stephane Bianco