Ivar KJELBERG
                                                                                                                                                    COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
                                                         
                            
                         
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                14 nov. 2011, 03:04 UTC−5                            
                        
                        
                                                    Hi
why not use 3D shell or 2D plate physics, your model will be lighter, then once you know all the details of your membrane behaviour you could try a 3D case in full solid, perhaps by using a section and symmetry to study a detail case and to verify that your 3D is equivalent to the simpler 2D and 2.5D cases
--
Good luck
Ivar                                                
                                                
                            Hi
why not use 3D shell or 2D plate physics, your model will be lighter, then once you know all the details of your membrane behaviour you could try a 3D case in full solid, perhaps by using a section and symmetry to study a detail case and to verify that your 3D is equivalent to the simpler 2D and 2.5D cases
--
Good luck
Ivar                        
                                                
                                                                                                            
                                             
                    
                    
                        
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                14 nov. 2011, 04:35 UTC−5                            
                        
                        
                                                    Hi Ivar,
              Thanks for your reply. I could try in 2D but how to define a Circle in it and also
1) later i will be fixing the membrane with Beams (now it is completely clamped), is there any function to vary the number of beams (like i could draw it once and use it as a template later)
2) Is there an option to view the model out of scale (when the thickness is only 5um, i have to zoom in a lot to select the edges. It would be much easier if i could represent the model out of scale)
Regards
Sanjay                                                
                                                
                            Hi Ivar,
              Thanks for your reply. I could try in 2D but how to define a Circle in it and also
1) later i will be fixing the membrane with Beams (now it is completely clamped), is there any function to vary the number of beams (like i could draw it once and use it as a template later)
2) Is there an option to view the model out of scale (when the thickness is only 5um, i have to zoom in a lot to select the edges. It would be much easier if i could represent the model out of scale)
Regards
Sanjay                        
                                                
                                                                                                            
                                             
                    
                    
                        
                            
                                                                                        
                                Ivar KJELBERG
                                                                                                                                                    COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
                                                         
                            
                         
                                                
    
        Please login with a confirmed email address before reporting spam
     
    
 
                                                Posted:
                            
                                1 decade ago                            
                            
                                14 nov. 2011, 08:13 UTC−5                            
                        
                        
                                                    Hi
1) take care with beam and solid as beams , shell and 2D plates have rotational DoF, while Solid have only spatial displacements, this means some additional model writing to link these DoFs
2) there is in the Definition View ... sub node a "Preserve aspect ratio" check box to change for MES high aspect ratio views
--
Good luck
Ivar                                                
                                                
                            Hi
1) take care with beam and solid as beams , shell and 2D plates have rotational DoF, while Solid have only spatial displacements, this means some additional model writing to link these DoFs
2) there is in the Definition View ... sub node a "Preserve aspect ratio" check box to change for MES high aspect ratio views
--
Good luck
Ivar                        
                                                
                                                                                                            
                                             
                    
                    
                        
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                17 nov. 2011, 05:51 UTC−5                            
                        
                        
                                                    Thanks for the help..I really appreciate it
Regards
Sanjay                                                
                                                
                            Thanks for the help..I really appreciate it
Regards
Sanjay                        
                                                
                                                                                                            
                                             
                    
                    
                        
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                25 avr. 2013, 15:41 UTC−4                            
                        
                        
                                                    Hi Ivar,
I am working on a model to analyze the deflection of a thin polymer layer. I wish to have a pressure boundary load on each face of the layer. The model works until another boundary is added that should be designed to stop the displacement of the polymer layer; however, originally the polymer layer went through the lower limit prescribed by the box. I tried to add a prescribed displacement condition that would stop displacement when the layer hits the lower boundary. But when this condition was added the maximum number of iterations were reached without finding a solution. I was wondering if I was using the Prescribed displacement condition correctly. Essentially I want the layer to stop deforming once it reaches a deformation of -2.5 in the z direction. The input that I am currently using in the w0 field is -2.5*(w>-2.5).                                                
                                                
                            Hi Ivar,
I am working on a model to analyze the deflection of a thin polymer layer. I wish to have a pressure boundary load on each face of the layer. The model works until another boundary is added that should be designed to stop the displacement of the polymer layer; however, originally the polymer layer went through the lower limit prescribed by the box. I tried to add a prescribed displacement condition that would stop displacement when the layer hits the lower boundary. But when this condition was added the maximum number of iterations were reached without finding a solution. I was wondering if I was using the Prescribed displacement condition correctly. Essentially I want the layer to stop deforming once it reaches a deformation of -2.5 in the z direction. The input that I am currently using in the w0 field is -2.5*(w>-2.5).                        
                                                
                                                                                                            
                                             
                    
                    
                        
                            
                                                                                        
                                Ivar KJELBERG
                                                                                                                                                    COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
                                                         
                            
                         
                                                
    
        Please login with a confirmed email address before reporting spam
     
    
 
                                                Posted:
                            
                                1 decade ago                            
                            
                                26 avr. 2013, 02:20 UTC−4                            
                        
                        
                                                    Hi
if you do not want to add contact physics  (often require some tweaking to get running smoothly, I would propose that you use rather a "model Definition Function step() because this is a "smooth function, your Boolean operator there is a very sharp edges function and that often gives problems to the solver.
The solver works best on smooth continuous functions, so try to use all driving equations that are continuous and check carefully initial conditions particularly for time or transient analysis
--
Good luck
Ivar                                                
                                                
                            Hi
if you do not want to add contact physics  (often require some tweaking to get running smoothly, I would propose that you use rather a "model Definition Function step() because this is a "smooth function, your Boolean operator there is a very sharp edges function and that often gives problems to the solver.
The solver works best on smooth continuous functions, so try to use all driving equations that are continuous and check carefully initial conditions particularly for time or transient analysis
--
Good luck
Ivar                        
                                                
                                                                                                            
                                             
                    
                    
    
                        
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                26 avr. 2013, 11:56 UTC−4                            
                        
                        
                                                    Thank you very much. It worked wonderfully                                                
                                                
                            Thank you very much. It worked wonderfully