A method for forming a multi-layered structure comprising: pulling a fibrous material consecutively through an injection box, an optional cooling box, a first die, and a second die of a multi-die pultrusion device, wherein the first die and the second die are separated by an intermediate region; forming a resin-infused fibrous material by introducing a liquid resin component onto the fibrous material within the injection box such that the fibrous material is at least partially impregnated with and at least partially surrounded by the liquid resin component; forming a partially-cured fiber-reinforced core material by heating the resin-infused fibrous material to a first temperature and for a first time sufficient to partially cure the liquid resin component within the first die of the multi-die pultrusion device; shaping the partially-cured fiber-reinforced core material to an outer profile shape while removing the partially-cured fiber-reinforced core material from the first die by pulling the partially-cured fiber-reinforced core material through a die opening in the first die and into the intermediate region between the first die and the second die; applying one or more layers of a polymer material onto at least a portion of the outer profile surface of the partially-cured fiber-reinforced core material within the intermediate region between the first die and the second die; and introducing the partially-cured fiber-reinforced core material having the applied one or more layers into the second die and heating the partially-cured fiber-reinforced core material having the applied one or more layers to a second temperature and for a second time sufficient to substantially cure the liquid resin component and form a fiber-reinforced thermoset core material, wherein one of the applied one or more layers is adhered onto an outer surface of the fiber-reinforced thermoset core material, thereby forming the multi-layered structure. pulling a fibrous material consecutively through an injection box, an optional cooling box, a first die, and a second die of a multi-die pultrusion device, wherein the first die and the second die are separated by an intermediate region; forming a resin-infused fibrous material by introducing a liquid resin component onto the fibrous material within the injection box such that the fibrous material is at least partially impregnated with and at least partially surrounded by the liquid resin component; forming a partially-cured fiber-reinforced core material by heating the resin-infused fibrous material to a first temperature and for a first time sufficient to partially cure the liquid resin component within the first die of the multi-die pultrusion device; shaping the partially-cured fiber-reinforced core material to an outer profile shape while removing the partially-cured fiber-reinforced core material from the first die by pulling the partially-cured fiber-reinforced core material through a die opening in the first die and into the intermediate region between the first die and the second die; applying one or more layers of a polymer material onto at least a portion of the outer profile surface of the partially-cured fiber-reinforced core material within the intermediate region between the first die and the second die; and introducing the partially-cured fiber-reinforced core material having the applied one or more layers into the second die and heating the partially-cured fiber-reinforced core material having the applied one or more layers to a second temperature and for a second time sufficient to substantially cure the liquid resin component and form a fiber-reinforced thermoset core material, wherein one of the applied one or more layers is adhered onto an outer surface of the fiber-reinforced thermoset core material, thereby forming the multi-layered structure.