**RSICC CODE PACKAGE PSR-485**

**1. NAME AND TITLE**

EPIPE: Code System for Static and Dynamic Piping System Analysis.

**2. CONTRIBUTORS**

The CDC version was contributed by Brookhaven National Laboratory, Upton, New York, through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

The CRAY version was contributed by Brookhaven National Laboratory, Upton, New York, through the NEA Data Bank, Issy-les-Moulineaux, France.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN IV; CDC7600

FORTRAN 77; CRAY-YMP (P00485CY00000).

**4. NATURE OF PROBLEM SOLVED**

EPIPE is used for design or design evaluation of complex large piping systems. The piping systems can be viewed as a network of straight pipe elements (or tangents) and curved elements (pipe bends) interconnected at joints (or nodes) with intermediate supports and anchors. The system may be subject to static loads such as thermal, dead weight, internal pressure, or dynamic loads such as earthquake motions and flow-induced vibrations, or any combination of these.

**5. METHOD OF SOLUTION**

From the displacement formulation, EPIPE determines the response of a piping system under static load defined as the equilibrium conditions given in matrix form. The equilibrium equations are solved using the Gaussian elimination method. Decomposition of the stiffness matrix and load vector is performed first. Then, using backward substitution, the displacement components at the active nodes are determined. After the displacements are found, the member forces of each pipe element are computed. The stresses at any point in a pipe element can be calculated from the member forces and internal pressure. The dynamic analysis may be carried out using the mode superposition method, the step-by-step direct integration method, or the response spectrum method. When the mode superposition or response spectrum method is used, the natural frequencies and mode shapes are first calculated from the generalized eigenvalue problem. Two different solution procedures are available, a determinant search technique and a subspace iteration method. The equation of motion representing the dynamic response of a piping system can be solved directly by numerical integration techniques.

**6. RESTRICTIONS OR LIMITATIONS**

None noted.

**7. TYPICAL RUNNING TIME**

Problem dependent.

**8. COMPUTER HARDWARE REQUIREMENTS**

EPIPE uses the CDC Level 2 method to allocate its working space in the CDC version. A Cray source file is also included.

**9. COMPUTER SOFTWARE REQUIREMENTS**

The SCOPE operating system and a Fortran IV compiler are required for the CDC Version. UNICOS 7.0.4 and a Fortran 77 compiler are required for the Cray-YMP version.

**10. REFERENCE**

M. Subudhi and P. Bezler, "EPIPE - Piping Analysis Program User's Manual - Version 1981," BNL-NUREG-30784 (December 1981).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced document and one 3.5" diskette containing the Fortran source written in DOS format. No executable accompanies this package.

**12. DATE OF ABSTRACT**

June 1991, revised September 2000. CDC7600 version submitted December 1990 and compiled by NESC February 1991 on a Cray X MP.

** KEYWORDS:** PIPE FRACTURE; RISK ASSESSMENT