RSICC CODE PACKAGE PSR-404

1. NAME AND TITLE

CORTES: Code System for Thermal & Mechanical Analysis of Tees.

2. CONTRIBUTORS

Oak Ridge National Laboratory, Oak Ridge, Tennessee, and University of California, Berkeley, California, through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM360 (P00404I036000).

4. NATURE OF PROBLEM SOLVED

CORTES is a package consisting of five finite element programs developed for the stress analysis of ANSI Bl6.9 tee joints. The five programs are: SA, the stress analysis program which analyzes pipe joints for the effects of internal pressure and arbitrary combinations of bending moment, torsional moment, axial force, and sheer force on the ends of the branch and run pipes. A limited temperature stress analysis capability is provided. EP, the elasto-plastic stress analysis program which analyzes pipe joints for the effects of internal pressure and arbitrary combinations of forces, including moments, and displacements, including rotations, imposed on the ends of the run and branch pipes. THFA, the transient heat flow analysis program which determines the time history of temperature variations in the pipe joints. The joint is assumed initially to be at a uniform temperature. Temperature changes are then specified at the inner surface, and a heat flow analysis is performed assuming a perfectly insulated outer surface. SHFA, the steady-state heat flow analysis program which determines the steady-state temperature distribution in pipe joints. Temperatures are specified on given cross-sections of the branch and run portions of the tee joint, and the temperature distribution throughout the remainder of the joint is calculated assuming the inner and outer surfaces are perfectly insulated. TSA, accepts as input, the output data from THFA or SHFA and performs the thermal stress analysis on the pipe joints.

5. METHOD OF SOLUTION

The joint is idealized as a system of 8-node hexahedral finite elements. A modified Zienkiewicz-Irons isoparametric element which has superior bending properties compared with the unmodified isoparametric element is used. The transient heat flow (THFA) problem is solved by a step-by-step integration procedure assuming linear variation of temperature with time within a step.

6. RESTRICTIONS OR LIMITATIONS

EP Displacements and strains are assumed to be small and no geometric (initial stress) stiffness effects are considered. The materials are assumed to yield according to the von Mises criterion, and tangent stress-strain relationships after yield are determined according to conventional flow rule procedures for strain hardening materials. THFA, The specified temperature variations at the inner surface are assumed to be symmetrical about the x-y plane. SHFA, The temperature distribution is assumed to be symmetric about the x-y plane. SA and TSA, Any nodes introduced within the wall thickness are assumed to be uniformly spaced through the thickness.

7. TYPICAL RUNNING TIME

Execution time varies according to the data used. Excluding wait time, it took approximately 140, 190, 40, 30, and 120 seconds to compile and execute each of the five test problems on an IBM370/195. A large amount of wait time is attributable to numerous I/O operations and is inversely proportional to the size of the container array, A.

8. COMPUTER HARDWARE REQUIREMENTS

All five programs use card input and a line printer. CORTES was developed on an IBM 370/195 and has not been upgraded. CORTES was tested at the NESC on an IBM 370/195 in 1978. CORTES was transferred to RSICC in 1999 and was not tested because of numerous compilation errors encountered with Fortran 77 compilers.

9. COMPUTER SOFTWARE REQUIREMENTS

The code ran under OS/360 and required a FORTRAN IV compiler.

10. REFERENCES

a) Included in documentation:

"CORTES, NESC No. 759.360," National Energy Software Center Note 78-28 (July 11, 1978).

A.N. Gantayat and G.H. Powell, "Stress Analysis of Tee Joints by the Finite Element Method," UC SESM 73-6 (ORNL-3193-1) (February 1973).

G. H. Powell, "Finite Element Analysis of Elasto-Plastic Tee Joints," ORNL-Sub-3193-2 (September 1974).

b) Background information:

R. E. Textor, "User's Guide for SHFA: Steady-State Heat Flow Analysis of Tee Joints by the Finite Elements Method," UCCND/CSD/INF-60 (January 1976).

11. CONTENTS OF CODE PACKAGE

Included in the package are the referenced documents in (10.a) and one CD. Also included is a copy of sample output produced by NESC at ANL which was scanned and added to the package as a PDF file. No executables are included with the package.

12. DATE OF ABSTRACT

February 2000.

KEYWORDS: HEAT TRANSFER; NUCLEAR SAFETY