Work began in mid-1980's when US/German finite element software (e.g. NASTRAN / ASKA) was simply not available

A pure S&T exercise led to a successful commercial product 10 years later (library package market)

Perhaps the best element library

Five licences sold

Led to three new theoretical principles!

F Package

The FEPACS packages uses a simple general purpose finite element programme structure permitting static, dynamic and thermal stress analysis options for laminated composites. Its element library contains a spring,truss,laminated beam,plate/shell and brick elements. Pre-and Post-processing modules are being designed to make analysis more user-friendly. The code is currently written in FORTRAN. It is highly portable and is now available on PC, workstation and supermini platforms

F Potential

• The package can be used as a production analysis tool for static, dynamic,thermal stress analysis of laminated structures
• As an open-ended development package, its availability in source code form allows users to enhance the capabilities of the package to suit their specific requirements
• As a research test bed and tool, the comprehensive documentation of the basic research on its element development in the open literature and the availability with source listing will encourage research students to experiment with finite element methodology directly using FEPACS as a test bed

F Validation

Standard as well as in-house design validation and benchmark tests have been used to qualify the robustness and accuracy of the elements. These include the patch test, Robinson's single element tests, McNeal and Harder's tests, along with spectral analysis

F Availability

• The software and know-how are now offered for release by NAL to any interested party as a general purpose code FEPACS, which now incorporates the family of field-consistent elements for analysis of composite structures
• As stand alone elements, coded and tested in FORTRAN and C, for integration into any software system or general purpose package
• In the form of technical consultancy to design, test, validate and deliver these elements and also to provide for porting and testing in host environments of vendor's packages

F Science

The element library in FEPACS has been designed and validated using the consistency concepts developed over 15 years of basic research at NAL. These have been published in the open literature (over 30 papers in leading journals) and have now been consolidated in a book: The Finite Element Method in Structural Mechanics, Kluwer Academic Publishers, Dordrecht, 1993

F Salient Features

• Consistent
• Variationally correct field reconstitution
• Material construction: very general
• Varying sectional rigidities
• Consistent load vector
• Diagonal and consistent mass matrices
• Geometric stiffness matrix
• Linear static/dynamic/buckling analysis
• The software is highly 'modular' in nature

F Element Library

• Spring : 2-noded constant stiffness spring element
• Truss : 2-noded truss element
• Tbeam 2: 2-noded composite beam element (Timoshenko)
• Ebeam2 : 2-noded composite beam element (Classical)
• Tbeam3 : 3-noded general curved composite beam element(Timoshenko)
• Mempsax: 3-noded triangular and 4-noded quadrilateral orthotropic plane stress, plane strain, axisymmetric elements and membrane elements
• Shell 4: 4-noded composite plane-shell(warped) element
• Shell 8: 8-noded composite degenerated shell element
• Shell 9: 9-noded composite degenerated shell
• Hexa 8 : 8-noded orthotropic hexahedral element
• Hexa 27: 27-noded hexahedral element