Incompatible Three-Dimensional Hexagonal Finite Elements by Multivariable Method

다변수 변분해법에 의한 비적합 8절점 육면체 요소

  • 주상백 (서울대학교 터보동력 기계센터) ;
  • 신효철 (서울대학교 기계설계학과)
  • Published : 1996.07.01


This paper introduces two three-dimensional eight-node hexagonal elements obtained by using multivariable variational mehtod. Both of them are based on the modified hellinger-reissner principle to employ incompatible displacements and assumed stresses of assumed strains. The internal functions of element are introduced to as element formulation through two different methods : the first one uses the functions determined directly from the element boundary condition of the incompatible displacements ; while the second, being a kind of B-bar mehtod, employs the modification technique of strain-displacement matrix to pass the patch test. The elements are evaluated on the selective problems of bending and material incompressibility with regular and distorted meshes. The results show that the new elements perform with good accuracy in both of deformation and stress calculation and they are insensitive to distorted geometry of element.


Incompatible Displacement;Multivariable Variational Formulation;Incompressibility Locking