DBEM
Direct Boundary Element Method for 2D Elastic Stress

DBEM is a FORTRAN77 program which uses the direct boundary element method (DBEM) to analyze a problem in 2D elastic stress.

Related Data and Programs:

FEM2D_HEAT is a FORTRAN90 program which solves the 2D time dependent heat equation on the unit square.

FEM2D_POISSON is a FORTRAN90 program which solves the 2D Poisson equation on a rectangle, using the finite element method, and piecewise quadratic triangular elements.

FEM2D_SAMPLE is a FORTRAN77 program library which evaluates a finite element function defined on an order 3 or order 6 triangulation.

FREE_FEM_HEAT is a FORTRAN90 program which uses the finite element method and the backward Euler method to solve the 2D time-dependent heat equation on an arbitrary triangulated region.

FREE_FEM_NAVIER_STOKES is a FORTRAN90 program which solves the 2D incompressible Navier Stokes equations in an arbitrary triangulated region.

FREE_FEM_POISSON is a FORTRAN90 program which solves Poisson's equation on a triangulated region, using the finite element method.

Reference:

1. Prasanta Banerjee, Roy Butterfield,
   Boundary Element Methods in Engineering Science,
   McGraw-Hill, 1994,
   ISBN: 0070841209,
   LC: TA347.B69.B36.

Source Code:

• dbem.f, the source code.
• dbem.csh, commands to compile the source code.

Examples and Tests:

• input.txt, an input file.
• output.txt, the output file.

List of Routines:

• MAIN is the main program for DBEM.
• ASMBLR
• ASSM
• AUTINT chooses the order of the integration rule.
• AXKRNL sets up integration kernels for the axisymmetric case.
• BNDSTR calculates stresses at a boundary node.
• BUNSNT recovers the unknown sensitivity at the node.
• FORCE sets the right hand side for the sensitivity equation.
• FORCE1 finds the right hand side of the sensitivity equation.
• GAUSSP sets the Gauss points and weights for the interval [0,1].
• INPUT reads input defining the problem to be solved.
• INPUTL reads the sensitivity information.
• INPUTL1 reads the sensitivity information when ISENS = 2.
• INTEGRA1 carries out the integration needed for assembly.
• INTSTR calculates interior stresses and displacements.
• MATCON calculates material constants for displacement and stress kernels.
• MESHGN generates the mesh.
• NORMAL handles the calculation of direction cosines of the node normal.
• NORMPT calculates the direction of the normal vector.
• NORSET sets up integration kernels for the nonsingular case.
• PARTIN
• PLKRNL integrates BIE kernel shape function products for stress and strain.
• SETUP
• SINSET sets up integration for the singular case.
• SOLVER solves the linear system.
• SOLVER_LU solves the system using LU decomposition.
• STORE stores the F and G matrices for subsequent usage.
• STRKER computes interior stress kernels.

You can go up one level to the FORTRAN77 source codes.