The concept of an equivalent solid material is used to obtain elastic-plastic solutions for circular plates under uniform pressure. Plates with elastically constrained outer edges are considered for the entire range of constraint stiffnesses. Results are obtained for plates perforated in a regular triangular patkern over the entire range of ligament efficiencies used in design. Since such plates may be supported by shells having limited yield moments@ solutions are also given for an arbitrary edge moment support. In addition to the limit load results@ solutions are given for the pressure at initial edge yielding and initial central yielding@ for the elastic-plastic moment distributions@ and for the plate deflections