Abstract: A tubular structural member has substantially constant cross-sectional size and configuration along its length between its opposite ends. The member has a pair of parallel oppositely aligned flat areas in its exterior surface. The member has substantially uniform wall thickness except in a selected portion of each the opposing areas where the member's wall thickness is a selected amount greater than the uniform wall thickness. The increase wall thickness preferably is manifested in the interior of the tubular member. The cross-sectional area of the member can have orthogonal neutral axes, and the exterior dimension of the member along one of those axes can be greater than the exterior dimension of the member along the other of those axes which is normal to the exterior flat areas; the amount and distribution of the thickening of the member's walls over the uniform thickness can be defined to cause the section modular of the member about each of the neutral axes to be substantially equal.

Abstract: A node connector in a double layer grid-type of space frame preferably is an extrusion which includes an open-ended tubular portion for snugly at least substantially encircling a frame chord member of desired cross-sectional configuration which is disposable in the passage. The node connector has fixed external elements which extend along the connector parallel to the passage. Those elements define facing parallel flat surfaces arranged in at least two pairs of such surfaces. The surfaces of each pair lie equidistantly from a center plane between them. Each center plane is parallel to the passage axis and preferably includes the passage axis. Each pair of facing flat surfaces of the node connector can cooperate closely with opposite flat surfaces at the end of each of other frames framing member placed between the facing surfaces.

Abstract: A connection node for a double layer grid or truss system has at least one diagonal flange receiving a pair of diagonal framing members having surfaces that lie in a single diagonal plane parallel to the flange(s). Use of co-planar diagonal members that can be at various diagonal angles or vertical, simplifies node connections and permits variations in bay spacing to produce interesting architectural effects and to provide greater member density where structural loads are greater.