Abstract: An energy absorbing seismic brace for both retrofit and new construction. The brace comprises a central strut of either multi-legged or homogeneous section fabricated from low strength aluminum, whose characteristics maximize the seismic energy absorption for a building installation. This central strut absorbs energy at high weight-specific levels by virtue of the hysteresis in its load-deflection relationship. In order to eliminate the possibility of buckling of the energy absorbing strut when it passes through the compression portion of a load cycle, it is surrounded by a system of spacers and an external sleeve providing very high bending rigidity at low weight. The spacers may be fabricated from low-density foams, pseudo-concrete, fibrous composites, or metals, depending upon the application. The outer sleeve may also be fabricated from a variety of materials, depending upon whether the embodiment calls for the principal bending rigidity to be provided by the spacers or sleeve.

Abstract: An energy absorbing seismic brace for both retrofit and new construction. The brace comprises a central strut of either multi-legged or homogeneous section fabricated from low strength aluminum, whose characteristics maximize the seismic energy absorption for a building installation. This central strut absorbs energy at high weight-specific levels by virtue of the hysteresis in its load-deflection relationship. In order to eliminate the possibility of buckling of the energy absorbing strut when it passes through the compression portion of a load cycle, it is surrounded by a system of spacers and an external sleeve providing very high bending rigidity at low weight. The spacers may be fabricated from low-density foams, pseudo-concrete, fibrous composites, or metals, depending upon the application. The outer sleeve may also be fabricated from a variety of materials, depending upon whether the embodiment calls for the principal bending rigidity to be provided by the spacers or sleeve.

Abstract: A method for the manufacture of lattice fins for fluid-born bodies is provided. In one embodiment, lattice fins having a metallic cell structure are manufactured from strips or sheets of metal. In another embodiment, composite lattice fins are manufactured from a log assembly of elongated mandrels covered with a fiber reinforced composite material. After curing, individual fins are sliced from the log assembly. Upon removal of the mandrels, a cell structure is obtained. Combinations of the two embodiments are also provided.

Abstract: An energy absorbing seismic brace for both retrofit and new construction. The brace comprises a central strut of either multi-legged or homogeneous section fabricated from low strength aluminum, whose characteristics maximize the seismic energy absorption for a building installation. This central strut absorbs energy at high weight-specific levels by virtue of the hysteresis in its load-deflection relationship. In order to eliminate the possibility of buckling of the energy absorbing strut when it passes through the compression portion of a load cycle, it is surrounded by a system of spacers and an external sleeve providing very high bending rigidity at low weight. The spacers may be fabricated from low-density foams, pseudo-concrete, fibrous composites, or metals, depending upon the application. The outer sleeve may also be fabricated from a variety of materials, depending upon whether the embodiment calls for the principal bending rigidity to be provided by the spacers or sleeve.

Abstract: A pultrusion method produces a composite structural member having rigid elements embedded therein. The structural member may be a sandwich structure in which one or more rigid, pre-rigidized, or rigidizable composite or non-composite structural elements are introduced at regular or irregular positions within core elements. The structural member may also be formed from layers of resin-matrix fiber fabric into a structural cross-section, such as an I-beam or T-beam, with a bundle of pre-pultruded rods located at the bends or the web-flange intersection points within layers.