failplot MSWindows binaries added

failplot program was improved:

1. Hedge-Hog added
2. Simple 'help' added
3. Instalation programs added
4. Interface remolded

The instalation programs may be found here: download

Your contribution: Help to correct the documentation...

As I'm not a native english speaker, the documentation for this project (web site and PDF manuals) may need corrections related to spelling, grammar and style.

Suggestions are welcome.

CONTENTS

1. Introduction
2. Origins
3. Characteristics
4. Software
5. Third-party libraries
6. Extensions
7. Computational aspects
8. Goals
9. Help
10. TODO

1 INTRODUCTION

Any analysis of a mechanical system, such as car's chassis, building's wall, soil's dam or tunneling can take concepts from the Continuum Mechanics Theory. These concepts help the understanding of deformability and strength behaviour of bodies. Generally, the complex system of partial equations are solved by the Finite Element Method (FEM). However, the heart of such analysis is the elaboration of a well-suited Constitutive Law. This library was craftily created to translate math equations to understandable computer code in an easily way. Two consitutive models are implemented: SubCam (Cambridge-UK model for clays) and SubTij (Professor Nakai's model for soils). Other models are in preparation. A program to simulate laboratory tests and a FEM program are included. A goal is to simulate, from the mechanical point of view, common engineering materials, such as metals, polymers, soils and wood.

2 ORIGINS

This library was created to help simulate mechanical systems from the viewpoint of Continuum Mechanics. The origins of this system was a study on constitutive models for soils, firstly presented in the paper: "Implicit and explicit numerical integration schemes applied to elastoplastic constitutive laws for soils" - "Pedroso and Farias (2005)" - "IWS-Fortaleza - 2nd International Workshop in Computational Geotechnics" - "Fortaleza, Brasil".

3 CHARACTERISTICS

Some characteristics of the source code of this library are:

• Carefully designed C++ code;
• Each important concept is isolated (encapsulated) into classes;
• Easy to be extended (extensibility);
• Use of Mandel's tensor representation, wich makes easier the implementation of constitutive equations;
• Robust independent solver (LAPACK/ATLAS);
• Autoregistration that makes easier the addition of new element, model or solver. Pratically, the correspondent file may just be inserted into the main folder that it will be already registered to the whole library/FEM program.

4 SOFTWARE

Some programs are presented into this library, including:

a) MechSys/FEM - 3D Finite Element Program

This program has the main characteristics:

• Different types of FEM elements may be used in the same simulation
• Different degrees of freedom are allowed
• Four (global) solution schemes: ForwardEuler, ModifiedEuler, AutoInc (automatic increments) and NewtonRaphson
• Two local stress-update schemes: ForwardEuler and ModifiedEuler
• Very easy input file format

b) LabTestSim - Laboratory Test Simulator

c) PrmSeek - Parameters optimizer ('seeker')

d) FailPlot - Failure criteria plot program

5 THIRD-PARTY LIBRARIES

This library is open/free software and uses (only) other open source libraries such as:

• Blitz++: Scientific computing C++ library == TinyVector/Matrix used as tensors;
• BLAS/LAPACK/ATLAS: For vector/matrix/eigenvalues/dense solver computations;

6 EXTENSIONS

Although our research line is related to Geomechanics, we hope that this library may be used for other kind or researches, such as the ones from Mechanical Engineering (Automobile/Aircraft industry) and even the ones from fluid dynamics or heat flow.

We are working on the extension of this library so it can simulate:

• Couple between mechanical/saturated flow in granular materials (started; alpha version will soon be updated);
• Couple between mechanical/unsaturated flow in granular materials;
• Large displacements/Finite deformation;
• Dynamics and other kind of problems (earthquake);

7 COMPUTATIONAL ASPECTS

This library tries to use the newest concepts from Computer Engineering, although we are not CE specialists. Thus, we are looking to include additional libraries/concepts such as:

• LAM/MPI for parallel computations
• UMFPACK: unsymmetric multifrontal sparse LU factorization package
• SparseLib: library for efficient sparse matrix computations

8 GOALS

We see this library as a young project and we hope it will evolve and, perhaps, become a useful tool.

9 HELP

If you want to help, please contact us. Both mechanical/programming and language skills are very welcome. We are looking for translators (from Portuguese/Spanish to English). Also, if you can correct some orthographic/grammar/language-usage mistakes, please tell us.

10 TODO

Now we are working with (check our TODO list):

• New constitutive models for soils (anisotropy and structured behaviour);
• Coupled (Mech/Sat flow) FEM libraries;
• LabTestSim: Laboratory Test Simulator (uploaded);
• PrmSeek: Constitutive parameters "Seeker";
• Documentation (URGENT!).

EXAMPLES

From LabTestSim with Subloading tij model and Fujinomori clay under cyclic loading)