The quadratic finite element/strip with generalized degrees of freedom andtheir application

This paper presents a quadratic finite element with generalized degrees of freedom(GDOF) and a quadratic finite strip with GDOF based on the principle that the local displacement fields of elements should be compatible with t he global displacement field of the corresponding systems. Firstly, a globa l displacement field is developed using quadratic B-spline functions. Secon dly, local displacement fields of elements and strips are constructed, empl oying multi-term interpolation polynomials of second degree. Making the loc al displacement fields of elements and strips be compatible with their corr esponding global displacement fields, respectively, models of the finite el ement with GDOF and the finite strip with GDOF are accordingly generated. O n the other hand, the quadratic B-spline function is convenient to derive t he explicit form of characteristic equations for computing model because of its lower order, and accordingly simplifies the computation, compared with cubic and quintic spline functions. Several numerical examples demonstrate the accuracy, simplicity and versatility of the present element and strip in the analysis of thin-walled structures. (C) 2001 Elsevier Science B.V. A ll rights reserved.