Ivar KJELBERG
                                                                                                                                                    COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
                                                         
                            
                         
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                6 avr. 2013, 07:40 UTC−4                            
                        
                        
                                                    Hi
knitting together trusss, beam, shell and solid (or some of them) is always delicate, as the truss, beam shell are all 1 or 2 DoF lower than Solid, so ideally a point (end of) a beam or truss shold be linked to a boundary = surface on the solid, for that one need to use projection mapping, and weak constrains. Also beam, truss and shell solve for displacements and angles, and Solid only for displacements, so one need to couple correctly the angles from the beam/truss (or shell) to the sold correctly. Else one obtain "mechanisms" or hindges and funny results
All this is possible, it's only that COMSOL does not have any handy scripts to do it for us, we need to apply it by hand link by link. This is rather common in many traditional FEM programmes, but with COMSOL you can play with the equation too, to make your own hinges and links
--
Good luck
Ivar                                                
                                                
                            Hi
knitting together trusss, beam, shell and solid (or some of them) is always delicate, as the truss, beam shell are all 1 or 2 DoF lower than Solid, so ideally a point (end of) a beam or truss shold be linked to a boundary = surface on the solid, for that one need to use projection mapping, and weak constrains. Also beam, truss and shell solve for displacements and angles, and Solid only for displacements, so one need to couple correctly the angles from the beam/truss (or shell) to the sold correctly. Else one obtain "mechanisms" or hindges and funny results
All this is possible, it's only that COMSOL does not have any handy scripts to do it for us, we need to apply it by hand link by link. This is rather common in many traditional FEM programmes, but with COMSOL you can play with the equation too, to make your own hinges and links
--
Good luck
Ivar                        
                                                
                                                                                                            
                                             
                        
                        
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                25 avr. 2013, 05:33 UTC−4                            
                        
                        
                                                    thank you                                                
                                                
                            thank you