Integration algorithm of constitutive equation for zero-thickness interface element and its verification;

The Goodman interface elements were defined to contribute a nonlinear numerical model for the coupling finite elements and interface elements.

The 3-D beam element was used for simulating the stressdeformation characteristics of concrete thin-walled cylindrical piles,and the thin layer interface element was used for simulating the interaction between soil and piles.

No thickness contact element is employed to simulate the nonlinear behavior of interaction of pile-soil.

By applying EAS elements to describe the deformation characteristics of thin-walled concrete cylindrical piles and sheet contact elements to describe the interaction of thin-walled cylindrical piles and foundation soil,an finite element method for the stress analyzing of piles considering the interaction of piles and soil was presented.

First the formula for the contact element is given,and nonlinear dynamic contact equation is obtained.

WT5”BZ]:According to the turbine contact problem between the blade root and rotor, the three-dimensional contact surface elements are deduced.

The stiffness matrix of a three dimensional contact surface element is deduced from the principle of virtual work.

The stiffness matrix of three dimensional contact surface element is deduced basing on the principle of virtual work in this paper In order to evade rearranging nodes and elements due to variation of contact surface during contact procedure, the presetting elements are presented The method is validated by numerical example

This article is essentially concerned about a certain typical section in a hydraulic tunnel with construction cold joint,of which mechanical behaviors are simulated by using the plane to plane contact element in ANSYS.