ABSTRACT

Indealingwiththecomputeranalysisofthinflatplatesasimilarapproachis takenheretothatforthepreviousprogramFEPCST.Now,however,a rectangleistaken,sotheelementhasfournodes,andateachnodethere existsthreeunknowns-az-displacementwandtworotationsorslopes abouttheX-andy-axisex,By.Asbeforeafunctiondescribingthevariation ofwacrosstheelementisassumed,inthiscaseafourthorderpolynomial inthelocalcoordinatesxandy,withtheoriginofthelocalaxissystem beinglocatedatthecentreofelement.Arestrictionexistsontheformulation presentedhere:thesidesoftheelementmustbeparalleltothestructure (wholeplate)axes.Itisofnoteherethatthestiffnessmatrixfortheelement isbuiltupthroughworkingintheelement'sownlocalcoordinatesystem andnotasinFEPCST,wheretheglobalorstructuralcoordinatesystemwas used.