Relax.cpp is a development of analyo.c which was written specifically for the analysis of the British Museum Great Court roof, engineers Buro Happold, architects Foster and Partners, steel and glass contractors Waagner-Biro.
The program uses Alistair Day's Dynamic Relaxation technique and makes no assumption of small rotations. Instead rotations are handled by a rotation matrix in which the rotation is stored as a vector with a magnitude equal to one half the tangent of the rotation angle.
The program is Open Source and under continuing development. It should run under Mac OS X, Linux and Windows.
See, Sigrid Adriaenssens’ PhD Dissertation, ‘Stressed Spline Structures’, 2000, University of Bath, Section 2.3 ‘Six Degrees of Freedom Beam Elements’ for details of the theory. Email me, Chris Williams, with questions or comments.
zip file contining C++ source code
zip file contining Macintosh Xcode project and executable
zip file contining Dev C++ and Visual Studio projects, and executable from Dev C++
zip file containing data for British Museum Great Court roof
zip file containing all files to compile and run in Visual Studio 2010
Instructions for running programs
Theory of large rotations