Fractures started about holes in upper plate in the row of five holes. Maximum loads on joint. Tensile strain on gross section of under plate. Pounds per sq. inch. 31, 314 41,750 69, 710 41,750 Calked joint. 10"x.236 Square inches. 2.36 1.77 1.06 1.77 iron rivets, "Burden's best." Punched holes: Punch," diameter; die, 1" diameter. Fractured upper plate across row of rivet holes. Started fractures in upper plate at end of lap. |