This paper on "FE Modeling of Multiple Thermal-Elastic-Plastic-Body Contact in Finite Deformation and Its Application to Tube and Tubesheet Assembling" was presented at the NAFEMS World Congress on Effective Engineering Analysis - 25-28 April 1999, Newport, Rhode Island, USA.

Abstract

A strategy for analyzing the transient thermal coupling with the finite deformation of the multiple elastic-plastic bodies in frictional contact is presented. An arbitrarily shaped contact element strategy, named as node-to-point contact element strategy, is proposed to handle the thermocontact with friction. A general thermal-elastic-plastic constitutive equation by assuming the material properties to be temperature-dependent and a thermocontact constitutive equation based on the energy balance are deduced. The thermomechanical coupled problem is solved with a staggered algorithm. In this procedure, the static-explicit solution algorithm is applied to analyze the elastic-plastic deformation, which using the finite deformation theory to describe the nonlinear behavior of the deformation body and the contact action with each other during the deformation processes induced by the ordinary external loading and the 'thermal loading'. On the other hand, the static-implicit solution algorithm is applied to analyze the heat transfer induced by both the heat transfer boundary conditions (including heat transfer across the contact interfaces, which depends on the contact pressure etc.) and the mechanical contribution (such as due to friction and plastic deformation). Special methods based on the R-minimum strategy are presented to solve the interaction problem between the static-explicit mechanical analysis and static-implicit thermal analysis. To meet the practical requirement for the large scale calculation, a parallel algorithm for the above problem is presented based on the domain decomposition method and applied with choosing the candidate contact surfaces as sub-domain boundaries. Finally, as examples, the assembling process of multiple tubes to the tubesheet by using the hydraulic expansion processing is analyzed. and the influences of the thermal shock on the assembled structure is also investigated on the IBM SP2 multi-processor computer. This kind of tube and tubesheet assembling is widely used in a heat exchanger system of an electric power plant.