A woven preform for a reinforced composite material, which may be woven flat and folded into shape. The preform has a three-dimensional weave architecture with fill fibers woven to provide layer-to-layer interlocking of layers of warp fiber as well as interlocking of fibers within each layer. At least two legs extend from a base, the base and legs each having at least two layers of warp fibers. The legs may be parallel or angled to each other, or may have a variable width clevis in between. The outer ends of the base and/or the legs preferably have tapers formed from terminating layers of warp fibers in a stepped pattern.