PLASTIC COLLAPSE AT LAP JOINTS IN PRESSURIZED CYLINDERS UNDER AXIAL LOAD

Circular steel silos and tanks are often constructed from rolled-steel plates with welded or bolted lap splices. Where the lap runs horizont ally around the silo circumference, the lap connection causes a local eccentricity in the line of vertical thrust in the shell wall. This ec centricity induces high local bending stresses and circumferential mem brane stresses, which are detrimental to the strength of the structure . Although elastic buckling of the shell wall may be the critical fail ure mode for thin lap-jointed cylinders under axial load with no or sm all internal pressure, axisymmetric plastic collapse is the likely fai lure mode when the internal pressure is high, especially for relativel y thicker cylinders. This paper presents a detailed study of the axisy mmetric collapse behavior and strength of lap-jointed cylinders under combined axial compression and internal pressure and establishes easy- to-use design equations for such shells.