Lightweight fiber-reinforced polymer sandwich structures

Presented are fiber-reinforced polymer (FRP) sandwich structures， methods for making/using such FRP sandwich structures， and motor vehicles with a vehicle component fabricated from a compression molded thermoset or thermoplastic FRP sandwich structure. A multidimensional composite sandwich structure includes first and second (skin) layers formed from a thermoset of thermoplastic polymer matrix， such as resin or nylon， filled with a fiber reinforcing material， such as chopped carbon fibers. A third (core) layer， which is encased between the first and second skin layers， is formed from a thermoset/thermoplastic polymer matrix filled with a fiber reinforcing material and a filler material， such as hollow glass microspheres. The first， second and third layers have respective rheological flow properties that are substantially similar such that all three layers flow in unison at a predetermined compression molding pressure. These layers may be formed from the same thermoset/thermoplastic polymer material， and include the same fiber reinforcing material.