Basicrequirementforapplyingisoparametricelementisthattheelementhastobeconvexandnoviolentdistortionisallowed.Inthispaper,acubicquadrilateralsplineelementwith12nodeshasbeendevelopedusingthetriangularareacoordinatesandtheB-netmethod,whichcanexactlymodelthecubicfieldforquadrilateralelementwithbothconvexandconcaveshapes.Neithermappingnorcoordinatetransformationisrequiredandthesplineelementcanobtainhighaccuracysolutionsandinsensitivetomeshdistortions.
