A SUPER CONFORMING TETRAHEDRAL HYBRID ELEMENT BASED ON ANALYTICAL TRIAL FUNCTIONS

A novel class of super comforming tetrahedral hybrid element based on analytical trial functions is proposed. Different from the linear displacement coordinated interpolation format adopted by traditional isoparametric element, the displacement field of super comforming elements introduces high-order conforming assumptions including linear displacement derivatives such as rotational degree of freedom (RDOF), and the internal stress field introduces a complete first-order stress field analytical trial function based on the fundamental analytical solution of three-dimensional elasticity theory. Numerical examples indicate that this element has high computational accuracy and strong ability to resist mesh distortion compared with other types of elements, which helps improve the accuracy of finite element method.