An apparatus includes a first thermoset layer that includes a first fibrous material embedded in a first thermoset matrix. The apparatus also includes a second thermoset layer that includes a second fibrous material embedded in a second thermoset matrix. The second thermoset layer is coupled to the first thermoset layer to form a joint. Further, a gap is defined between the first thermoset layer and the second thermoset layer. The apparatus also includes a thermoplastic filler that is made from a thermoplastic material. The thermoplastic filler is positioned within the gap.