Release notes for SDT 5.3 and FEMLink 3.2

Contents Functions Index

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1.6 Release notes for SDT 5.3 and FEMLink 3.2

1.6.1 Key features

Key features of the SDT 5.3 release are

MATLAB 7 integration, this release takes real advantage of new Matlab 7 features. New support for the MATLAB 7.0 64 bit versions on Linux. This becomes the best platform to run large FEM models. The previous software limitation to 1.5 GB address space (4 GB on MACs) is no longer a difficulty.
Optimization efforts have been made on the feplot and iiplot which result in significant stability and speed gains when dealing with large data sets or models.
the new q4cs shell element based on an MITC4 formulation fixes limitations that existed in earlier shell elements. Classical lamination theory is fully supported and support of piezoelectric shells is under experimentation. Piezoelectric volume formulations are now supported.
The v_handle object now implement a number of out-of-core operations that can be used when dealing with large FEM models. This is used by feplot which can now dynamically read shapes from a file, fe_reduc which can use out of core operations and functions that use shapes read from a binary FEM file.
The incompatible mesh matching features feutilb Match (given a position find intrinsic coordinates within the matching volume of surface element) and
MpcFromMatch build linear constraints giving displacement and possibly rotation at the matched node) have been significantly enhanced. This is currently used for advanced connection models accessible through fe_case Connection commands. Possible uses of the base capability are enhanced test/analysis correlation capabilities, support for strain sensors, general non-conform mesh handling, contact problems, ...

OpenFEM has undergone major revisions to get it ready for fully non linear applications. Although no working application is distributed, a number of key capabilities are included in this distribution.

To ease the use for multi-physics problems, DOFs used by an element are now normally dependent on the declared element properties. Standard shapes (hexa8, ...) are thus topology holders (8 node volumes) rather than associated with a particular physics formulation. The implementation of a particular set of physics is now entirely defined in the associated property function p_solid for 2D and 3D mechanics, linear acoustics and fluid structure coupling, p_heat for the heat equation, p_piezo for piezoelectrive volumes and shells. Other applications not included in the distribution are the generation of layered shell models with variable numbers of layers or the development of poroelastic formulations based in Biot's model. This major change can affect the result of GetDof commands when the propertie are not defined.
Compilation for generic elements has progressed so that you can now define new formulations that include right hand side and stress computations with to need to enter of_mk or fe_mknl. These developments are associated with some performance enhancements and a more consistent set of error reports. sdtdef('diag',12) can now be used in a debugging mode for many assembly related problems. Non linear follower pressure forces are now supported.
The selection of integrations rules in the element properties is now consistently implemented. This is particularly important for non-linear problems but is also used in post-processing applications since it allows stress evaluations at other points than model assembly.
Time integration capabilities (fe_time) have been significantly enhanced with optimization for explicit integration and implementation of output subsampling techniques that allow for different steps for integration and output. Definitions of time variations of loads is now consistently made using curves (see fe_curve).
an interface to GMSH has been introduced to give an access to its interesting unstructured meshing capabilities.

Key features of FEMLink 3.2 are

nasread has been significantly optimized in particular for very large file support in relation with the v_handle object which allows random access to large data sets (deformations stored in .op2 and .op4 formats).
naswrite has been significantly extended for bulk genaration and editing, OUTPUT4 matrix writting, remote job handling.
ans2sdt now supports ANSYS 9 and 10 version.
perm2sdt the PERMAS reading interface has been fully rewritten allowing for much faster and consistent reading. Subcomponents are now supported.
samcef import/export capabilities to SAMCEF have been introduced.

For MATLAB compatibility see section 1.6.3.

1.6.2 Detail by function

fe_cyclic	Has undergone major revisions and now handles shells, general boundary conditions, computations at variable rotation speeds (for volume elements only) and more.
fe2ss	Extensions on the types of sensors and loads supported.
fe_sens	Significant extensions of placement methodologies have been added see [2].
fsc ...	compatible fluid structure coupling matrix is now compiled for all 2d topologies and supports geometrically non-linear problems.
hexa8 ...	2D and 3D volumes are now topology holders with physics being defined in property functions. Right hand side computations are now supported for generic elements.
quad4	Formulation 5 can now be used for call the new q4cs element which supports classical lamination theory (composites) and piezo electric electrodes experimentally.
ii_mac	minor robustness enhancements, improved figure and colorbar generation, MATLAB 7 compatibility
idopt	Matlab 7 compatibility and minor fixes.
fe_case	New Connection commands allow the creation of complex kinematic connections.
fe_eig	Support of the EigOpt case information. Fixes on FMAX support in solution 5.
fe_exp	The fixed sensor modes are now returned as a deformation structure.
feutil	Significant bug fixes for second order elements. A major speed improvement in the AddNode command. Support of radius based selections.
fe_load	The load assembly was fully revised to optimize the process for non linear operations. Compiled RHS computations for generic elements is now supported.
fe_fmesh	2D unstructure meshing capabilities in fe_fmesh qmesh have been extended for more consistent 3D shell meshing and return of local coordinates in the coarse mesh reference elements.

feplot, fecom	Significant enhancement of the material and property visualization interfaces, extensions of context menus, support of large deformation sets stored on disk through v_handle objects.
p_piezo	supports piezo-electric volumes elements
p_heat	solutions to the heat equation problem.

1.6.3 Notes by MATLAB release

MATLAB 6.5, 7.0.x to 7.2 (2600a)

SDT 5.3 and FEMLink 3.2 are developed for these versions of MATLAB and is fully compatible with them.

This is the last release that will support MATLAB 6.5 compatibility, since new MATLAB 7 capabilities justify a phase out (as soon as edge transparency bugs in the MATLAB OpenGL implementation are finally fixed).
MATLAB 6.1 and earlier

Due to significant GUI incompatibilities, this version of MATLAB is no longer tested and thus supported on these releases. Applications that use SDT for pure computations will probably run properly.