are induced in an outer surface in at least one of the beam members and at least partially retained by the cured bond the stresses are such that a significant compression prestress is induced at the bottom surface of the structural support whereby it is capable of carrying a much greater load represented by the compression prestress at the bottom surface application_number US 86895286 A description the invention can best be understood with reference to the embodiment depicted in fig1 as shown the structural support member 10 is comprised of a first elongate beam member 12 which overlies a second elongate beam member 14 the beam members are joined together along an adhesive bond joint 24 extending the length of and between the members although not necessary as explained below beam members 12 14 as shown are of the same height each beam member 12 14 has a top surface 16 18 respectively and a bottom surface 20 22 respectively as shown both beam members 12 14 are curved and stressed the result of being curved and bonded together by adhesive joint 24 extending the length of the beam members between surfaces 18 20 the support member 10 is prestressed in its manufacture by applying an adhesive such as a gap filling phenol resorsinol adhesive between beam members 12 and 14 to form adhesive joint 24 before the adhesive appreciably cures the central portion of beam 10 is deflected by imparting transverse bending forces until the beam has a cambered profile represented by the dashed lines 16a 22a in fig1 as shown the cambered profile is circular over the length of the beam with.