Solutions are presented for two stress distribution problems which result from breaking of the filaments in a composite material composed of high modulus elements embedded in a low modulus matrix. Both problems represent extensions of the two-dimen sional filamentary structure stress concentration problem: the first concerns the determination of static stress concentration factors in the unbroken elements of a three-dimensional square or hexagonal array where specified filaments are broken; the second involves the stress concentration factor in the element adjacent to a broken filament in a two-dimensional array where the shear stress in the matrix adjacent to the broken filament is restricted by a limit stress in an ideally plastic sense.