A composite structure comprising: a plurality of components coupled together forming a joint , wherein said plurality of components are oriented such that a gap is defined at least partially therebetween; and a filler structure positioned in said gap , said filler structure comprising a closed cell foam core , which facilitates restricting delamination of the composite structure , wherein: said closed cell foam core comprises a plurality of core cells that comprise side walls configured to yield plastically in response to hydrostatic tensile forces, said plurality of core cells comprise void spaces defined by said side walls ; said void spaces are substantially filled with air; said closed cell foam core is fabricated from a material such that said side walls yield plastically in response to hydrostatic tensile forces applied to and by the composite structure in use; said void spaces facilitate enabling said closed cell foam core to absorb energy and facilitate defining a porosity within said closed cell foam core ; the porosity of said closed cell foam core is selected such that said closed cell foam core has a predetermined energy absorbing capability and bulk compression stiffness; and said closed cell foam core has a porosity within a range defined between about 20 percent and about 40 percent by volume of said closed cell foam core . a plurality of components coupled together forming a joint , wherein said plurality of components are oriented such that a gap is defined at least partially therebetween; and a filler structure positioned in said gap , said filler structure comprising a closed cell foam core , which facilitates restricting delamination of the composite structure , wherein: said closed cell foam core comprises a plurality of core cells that comprise side walls configured to yield plastically in response to hydrostatic tensile forces, said plurality of core cells comprise void spaces defined by said side walls ; said void spaces are substantially filled with air; said closed cell foam core is fabricated from a material such that said side walls yield plastically in response to hydrostatic tensile forces applied to and by the composite structure in use; said void spaces facilitate enabling said closed cell foam core to absorb energy and facilitate defining a porosity within said closed cell foam core ; the porosity of said closed cell foam core is selected such that said closed cell foam core has a predetermined energy absorbing capability and bulk compression stiffness; and said closed cell foam core has a porosity within a range defined between about 20 percent and about 40 percent by volume of said closed cell foam core . said closed cell foam core comprises a plurality of core cells that comprise side walls configured to yield plastically in response to hydrostatic tensile forces, said plurality of core cells comprise void spaces defined by said side walls ; said void spaces are substantially filled with air; said closed cell foam core is fabricated from a material such that said side walls yield plastically in response to hydrostatic tensile forces applied to and by the composite structure in use; said void spaces facilitate enabling said closed cell foam core to absorb energy and facilitate defining a porosity within said closed cell foam core ; the porosity of said closed cell foam core is selected such that said closed cell foam core has a predetermined energy absorbing capability and bulk compression stiffness; and said closed cell foam core has a porosity within a range defined between about 20 percent and about 40 percent by volume of said closed cell foam core . <EOS>