Theoretical evaluation of required plastic work in bulging of statically loaded plate

Abstract EN

Finding the amount of plastic deformation into metallic plates, metallicstructures, ships frame, bodies of different types of cylinders and reservoirsbodies as a result of exposure tostaticor dynamic forceis so necessary todetermine the extent of distortionand destructionhappening intheseobjects and this is one of the main factors in design calculations to determine the dimensions and thicknesses of these bodies.

Derivation anew theoreticalmodelto calculate theamount of work and forcerequired to bulge the sheet metalisa very important targetbecause of the lack of a theoretical relations to calculate the work of plastic deformation with good approximationoridenticalto exact required work and force ; or vice-versa to find the amount of plastic deformation as a result of a specific work or specific force.

This was donein this research where a theoretical model has been derivedthrough the expense of work and force necessary to generatebulging in sheet metal.

This theoretical model has been adopted on the mildsteel plates which are of wide application in practical life.

Results obtained from the theoretical model were compared with those obtained from tests conducted onsimply supported circular steel plates made from low carbon steel, milled steel, of a (280) mm diameter and (1, 2, 3, 4, 5, 6, 8, 10) mm thickness andexposed to central force applied by a flat ended punch of 10 mm diameter.

The applying force was increased gradually till it caused plastic deformation in the sheet, and then reached the state of shear of the disk, which is located under the punch.

Results comparison appear matchorsubstantial convergence between the practical resultsand those obtained from the theoretical model to find the work and for ceit takes to plastic deformation in the tested plates.