Pre-formed thermoplastic filler for thermoset structure

A method for making a joint for a structure, comprising:

• forming a thermoplastic filler made from a thermoplastic material;
• applying an uncured first thermoset layer onto the thermoplastic filler, the uncured first thermoset layer comprising a first fibrous material embedded in a first thermoset matrix;
• applying an uncured second thermoset layer onto the thermoplastic filler and into contact with the uncured first thermoset layer, the uncured second thermoset layer comprising a second fibrous material embedded in a second thermoset matrix;
• and
• while the uncured first and second thermoset layers are applied onto the thermoplastic filler and while the uncured second thermoset layer contacts the uncured first thermoset layer, curing the uncured first thermoset layer and the second thermoset layer to for a cured first thermoset layer and a cured second thermoset layer and bond together the cured first thermoset layer, the cured second thermoset layer, and the thermoplastic filler.

A method for making a joint for a structure, comprising:

• forming a thermoplastic filler made from a thermoplastic material;
• applying an uncured first thermoset layer onto the thermoplastic filler, the uncured first thermoset layer comprising a first fibrous material embedded in a first thermoset matrix;
• applying an uncured second thermoset layer onto the thermoplastic filler and into contact with the uncured first thermoset layer, the uncured second thermoset layer comprising a second fibrous material embedded in a second thermoset matrix;
• and
• while the uncured first thermoset layer and the uncured second thermoset layers are applied onto the thermoplastic filler and while the uncured second thermoset layer contacts the uncured first thermoset layer, curing the uncured first thermoset layer and the uncured second thermoset layer to form a cured first thermoset layer and a cured second thermoset layer and bond together the cured first thermoset layer, the cured second thermoset layer, and the thermoplastic filler without melting the thermoplastic filler.

A method for forming a joint, the method comprising:

• forming a first thermoset layer comprising a first fibrous material, embedded in a first thermoset matrix, and a first portion, having a first shape;
• forming a second thermoset layer comprising a second fibrous material, embedded in a second thermoset matrix, and a second portion, having a second shape, the second thermoset layer being coupled to the first thermoset layer to form the joint, wherein a gap is defined between the first thermoset layer and the second thermoset layer;
• forming a thermoplastic filler comprising a thermoplastic material and unidirectional reinforcement fibers, the thermoplastic filler;
• positioning the thermoplastic filler within the gap, and wherein:
• the thermoplastic material of the thermoplastic filler has a melting temperature that is greater than a cure temperature of each of the first thermoset matrix and the second thermoset matrix,
• the melting temperature of the thermoplastic material of the thermoplastic filler is between about 450° F. and about 750° F., and
• the thermoplastic filler supports and maintains the first shape of the first portion of the first thermoset layer and the second shape of the second portion of the second thermoset layer;
• and
• curing the first thermoset layer and the second thermoset layer without melting the thermoplastic material of the thermoplastic filler.