Henrik Sönnerlind
                                                                                                                                                    COMSOL Employee
                                                         
                            
                                                                                                                                                
                         
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                2013年10月14日 GMT+8 14:14                            
                        
                        
                                                    Dear Ruzbeh,
Since it is an eigenfrequency analysis, the size of the deformations is arbitrary. So without running a forced response analysis with actual loads in for example frequency domain, there is no way to know whether these parts would actually get in to contact or not. But if they do, there is nothing such as an eigenfrequency of the structure.
Regards,
Henrik                                                
                                                
                            Dear Ruzbeh,
Since it is an eigenfrequency analysis, the size of the deformations is arbitrary. So without running a forced response analysis with actual loads in for example frequency domain, there is no way to know whether these parts would actually get in to contact or not. But if they do, there is nothing such as an eigenfrequency of the structure.
Regards,
Henrik                        
                                                
                                                                                                            
                                             
                                            
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                2013年10月14日 GMT+8 19:06                            
                        
                        
                                                    Dear Henrik
Thank you for the reply. Basically this is a resonator. The frequency I got from my simulation has good agreement with experimental result. Since the deformations are arbitrary, I hope the contact between parts does not matter really. Does the problem become Non-linear when considering contact between parts?
I know the driving frequency of the resonator, is it possible to have a freqeuncy response analysis using this?
Thanks.                                                
                                                
                            Dear Henrik
Thank you for the reply. Basically this is a resonator. The frequency I got from my simulation has good agreement with experimental result. Since the deformations are arbitrary, I hope the contact between parts does not matter really. Does the problem become Non-linear when considering contact between parts?
I know the driving frequency of the resonator, is it possible to have a freqeuncy response analysis using this?
Thanks.                        
                                                
                                                                                                            
                                             
                        
                        
                            
                                                                                        
                                Henrik Sönnerlind
                                                                                                                                                    COMSOL Employee
                                                         
                            
                                                                                                                                                
                         
                                                
    
        Please login with a confirmed email address before reporting spam
     
    
 
                                                Posted:
                            
                                1 decade ago                            
                            
                                2013年10月15日 GMT+8 14:18                            
                        
                        
                                                    Hi Ruzbeh,
If the parts would actually come in contact at resonance, the problem becomes severely nonlinear and can only be simulated in time domain, and to a great effort. The solutions are no longer harmonic, and a lot of high frequencies will be generated by the impact.
If you know the driving frequency and load amplitude, then you should do a frequency response simulation to check that there is no contact. Note however that if you are close to resonance, the computed amplitudes will be strongly dependent on the damping values that you select.
Regards,
Henrik                                                
                                                
                            Hi Ruzbeh,
If the parts would actually come in contact at resonance, the problem becomes severely nonlinear and can only be simulated in time domain, and to a great effort. The solutions are no longer harmonic, and a lot of high frequencies will be generated by the impact.
If you know the driving frequency and load amplitude, then you should do a frequency response simulation to check that there is no contact. Note however that if you are close to resonance, the computed amplitudes will be strongly dependent on the damping values that you select.
Regards,
Henrik