Version 16.0

Victor

Mecway 16.0 is now available at the link below. As usual, it's a free update for all existing license holders.

https://mecway.com/download/mecway160.msi

Shells

All shell elements for the internal solver have been replaced with improved ones. This is an unusual update in that it changes the semantics of a model so existing models may become wrong. The difference occurs when they are both curved and have a large thickness or shell offset as shown in this picture:


Old shells (v1-15):

• Stiffness uses a flat projected geometry
  
• Loads use a curved geometry
  
• Can't correctly model some shapes such as a twisted beam.
  
• Suffer from hourglassing which is apparent with point constraints on structured meshes.
  
• The top and bottom faces are offset from the nodal plane in a single normal direction, meaning curved shells retain the same size and shape for both faces and with shell offset.
  

New shells (v16+):

• MITC3, MITC6-a, MITC4, and MITC8 formulations.
  
• Stiffness and loads use the same curved geometry.
  
• Works well for arbitrary curved structures as long as the radius of curvature is at least an order of magnitude greater than the thickness.
  
• No hourglassing but tri6 has some more subtle zero-energy modes.
  
• Faces are offset in the local normal direction so the outside of a curve has greater area than the inside.
  
• Curved shape is the same as CCX shells to the extent that CCX shell normals are not adjusted to match their neighbors.
  

New solution variables: Transverse shear force resultants (force per length VW and WU) and stress (stress in element coordinates VW and WU), and strain in global coordinates.
Von Mises stress now includes transverse shear stress.
Thermal stress can be used with orthotropic material and shell offset.
Tri3 and quad4 available in all analysis types that have shells.

Other changes

• New API functions mw.new_component(), mw.delete_component(), and mw.generate_mesh()
  
• Rotate/copy, Mirror/copy, Scale/copy, Revolve/copy, and Project onto surface can have their origin specified by mouse picking.
  
• Output file names for save after solve, export stiffness matrix / mass matrix / load vector / DOF ordering, and table can contain <f> to include the current file’s filename without extension.
  
• Reinstated graphical symbols for bonded contact that were removed in v15.
  
• For CCX, exports non-default orientations of solid and shell elements even if they have isotropic material.
  
• Display of element axes in deformed view shows the undeformed orientation.
  
• Removed the Smooth geometry preview option in Labs menu because it would now cause linked face selections to be mixed up in rare cases.
  
• Improved matching of surface selections between STEP file geometry view and mesh's linked face selections.
  
• Other bug fixes.
  

JohnM

Node pick center for Mesh Tools is great!

Sergio

Thanks for this new release. The mw.new_component() is ver usefull, have modified my script to create spiders so they fall in a new component without user interaction. Now I will try to make a new scrip to convert all the groups of elements (from Salome meshes) in components without user interaction as well.