Abstract: To produce a pultrusion which can be machined without undue strength loss bidirectional woven fiber fabric is modified to be pultrudable into a high shear strength composite member. In a preferred form of the invention the fabric is pleated in the pultrusion process to create an endless wall of stacked switch-back pleated layers which defines a box beam wall in one example, and the shaft of a bolt in another. Products produced by this process have improved isotonic strength qualities over currently produced pultrusions, which are limited to unidirectional fibers, continuous fiber mats, or alternating layers of non-woven 0.degree. and 90.degree. cloth and do not have the shear strength inherent in the pleated configuration.

Abstract: A high voltage electrical transmission line support structure is constructed virtually completely from glass reinforced composites, comprised of vertical ribs, reinforcing cross bracing members and a skin composed of composite panels, enabling the reduction in elevation and closer spacing of conductors, and the creation of a smaller support structure weighing half or less the weight of a steel tower of the same power rating. The resulting structure requires substantially less ground right-of-way, and EMF radiation is attenuated in the immediate tower area due to the closer phase spacing.

Abstract: Pultruded composite members which interfit to form a rigid post and beam, or beam and brace, are adapted for use in heavy construction in such applications as bridges, buildings including high rise structures, ship deck and the like. Two pultruded shapes are used for the entire framework. A first member ordinarily serving as a beam is pultruded as a completely enclosed thick-walled I-beam with an internal channel which is formed with a continuous scalloped or toothed cross-section on both sides. The mating support member has a bifurcated end with outer sides configured to interlock with the sides of the internal channel of the I-beam. Access into the channel is provided by periodic windows milled into the beam at the precise entry points of the insertion member. The bifurcated end of the insertion member compresses adequately to be inserted into the channel of the cross-beam, where it expands such that the external teeth engage the scalloped walls of the I-beam and lock securely into place.

Abstract: A structure derives its structural strength and integrity entirely from interlocked pultruded composite members. The disclosed techniques can be used in a wide variety of applications including replacement for steel frame structures and is especially useful where the electrical properties of steel are undesirable, such as in high voltage transmission towers. Two types of pultrusions are used as structural members to build the entire structure. Lock-in butt joints between all members are made by inserting the compressed ends of the resilient bifurcations of the crossmembers into openings in the receiving member, where they expand to lock in place and are blocked against subsequent compression by inserts. Channels spanning the entire column lengths permit insertion of a crossmember anywhere along the channel where there is an access opening.

Abstract: To produce a pultrusion which can be machined without undue strength loss bidirectional woven fiber fabric is modified to be pultrudable into a high shear strength composite member. In a preferred form of the invention the fabric is pleated in the pultrusion process to create an endless wall of stacked switchback pleated layers which defines a box beam wall in one example, and the shaft of a bolt in another. Products produced by this process have improved isotonic strength qualities over currently produced pultrusions, which are limited to unidirectional fibers, continuous fiber mats, or alternating layers of non-woven 0.degree. and 90.degree. cloth and do not have the shear strength inherent in the pleated configuration.