RSICC Home Page STABA, STAGT, STEGT, STIG, STIGMA

RSICC CODE PACKAGE PSR-575

1.         NAME AND TITLE

STABA, STAGT, STEGT, STIG, STIGMA - Stress Analysis of Dragon HTR Graphite Structure.

2.         CONTRIBUTORS

Dragon Project, A.E.E., Winfrith, Dorchester, U.K. through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France.

3.         CODING LANGUAGE AND COMPUTER

FORTRAN IV, FORTRAN 95; PC, Linux, Mac (P00575MNYCP00).

4.         NATURE OF PROBLEM SOLVED

Stress analysis of graphite structures for the DRAGON high temperature reactor is performed by this family of computer codes. Two-dimensional plane strain irradiation dose dependent core problems have been solved. 

5.         METHOD OF SOLUTION

STABA - Stress, Temperature and Bowing Analysis. The aim of this quasi 3-D computer code is to apply the principle of rotational plane strain over the full length of a prismatic core component, taking into account spatial variations in fast neutron and thermal flux throughout a period of irradiation, to obtain the stress and bowing effects. A 2-D thermal evaluation option has been included to save the time and work involved in the transfer of nodal point temperatures from other sources.

STAGT, which is the oldest in this series of programs, can handle multiple connected regions but is confined to plane strain in x-y geometry.  Variations in temperature loading during irradiation are accounted for in STAGT (Wigner strain component.).   

STIG is a version of STAGT where an anisotropic elasticity matrix has been introduced to handle transversely isotropic materials. An additional feature of 'STIG' is the introduction of a boundary restraint condition of practical importance to prismatic gas cooled reactor core construction. This is defined as rotational plane strain in which free distortion of the prism arising from overall gradient of temperature and/or fast neutron damage flux coincident with any single direction may be assumed to occur if variation of thermal expansion coefficient with irradiation is included. 

STIGMA is intended for evaluation of stress and displacement in composite axi-symmetrical bodies subject to variable loadings in the axial and radial directions. The code has been prepared to take account of transverse isotropy in material characteristics for up to four separate bonded interface zones within a single composite material problem. Although specifically designed for the analysis of graphite structural components in the fast neutron irradiation environment of a reactor core, it is equally applicable to initial state design of pre-stressed concrete pressure vessels and other problems involving rotational symmetry.

6.         RESTRICTIONS OR LIMITATIONS

None stated.

7.         TYPICAL RUNNING TIME

Entirely dependent on problem size.

8.         COMPUTER HARDWARE REQUIREMENTS

No executables are provided but the programs should work with any computer running Windows, Linux or MacOS, with a compatible compiler installed.  The codes were tested on IBM Thinkpad T61p; Apple iMac i7 2800MHz with MS Windows XP Professional; Ubuntu Linux 9.1 Kernel 2.6; Mac OS X 10.6.3 operating systems at the NEA Data Bank. They were also compiled and tested at RSICC on Windows 7, MacOS and Red Hat Linux using Intel PGI and GNU compilers.

9.         COMPUTER SOFTWARE REQUIREMENTS

The source code was written in FORTRAN IV and FORTRAN 95. A FORTRAN compiler is required.  

10.       REFERENCES

      a. included in documentation

            B.E. Pitchford: “STABA - Stress, Temperature and Bowing Analysis. A Code for Prismatic Graphite Core Components of High Temperature Reactors”, DPTN/782 (March 1976).

A.N. Kinread:  “STAGT - A Two Material Version of the STAG Code Embodying Wigner Improvements,” Dragon Project Report 892 (August 1974).

A.N. Kinkead: “STIG - Stress in Transversely Isotropic Graphite. Two-Dimensional Two Material Code Embodying Rotational Plane Strain as an Option,” D.P. Report 894 (August 1975); A.N. Kinkead: Addendum 1 to D.P. Report 894 (July 1975).

A.N. Kinkead: “STIGMA-Stress in Transversely Isotropic Graphite Made Axi-Symmetrically,” D.P. Report 978 (February 1976).

11.       CONTENTS OF CODE PACKAGE

The package contains source code, references, and sample problem input and output.

12.       DATE OF ABSTRACT

August 2012.

KEYWORDS:     STRESS ANALYSIS, TWO-DIMENSIONAL