This　paper　proposes　an　equivalent　2d　model　incorporating　translational　and　rotational　springs　to　simulate　constraints　in　the　stability　analysis　of　steel　plates　under　in-plane　patch　loading.　The　main　objective　is　to　develop　an　equivalent　stability　analysis　of　these　plates　by　accurately　calibrating　the　level　of　constraint　provided　by　the　stiffeners　and　flanges.　The　calibration　involves　determining　the　spring　constants　of　a　2d　equivalent　plate　model　to　achieve　the　same　linear　elastic　critical　load　and　buckled　shape　as　a　3d　model.　The　paper　uses　the　buckling　coefficient　as　the　objective　function　to　calibrate　the　translational　and　rotational　springs.　The　ultimate　goal　is　to　effectively　replicate　the　constraint　conditions　imposed　by　the　flanges　and　vertical　stiffeners　within　the　structure.　The　proposed　simplified　method　yields　results　that　closely　align　with　those　obtained　from　the　original　3d　model,　incorporating　finite-rigidity　restraints.