error in a normal mode analysis

Altair Forum User

I have a .igs file of a long beam of rectangular cross section.

I have to do a normal mode analysis for 10 modes.

Boundary condition is that the beam is cantilever.

But i am getting the error as below

'CQUAD4 element number 1 references a missing property ID 1

  or uses property of incorrect type for this element type.'

what does it mean??? 

Altair Forum User

Hi ashishbadgujar

 

have you assigned a property to the component(s) in your model?

 

please check whether any property and material is assigned to the compenent/element or not.

 

Also, what is the type of propety are you using. for CQAUD4 it should be PSHELL. 

Altair Forum User

ohhh...I have given property as PSOLID.

I just corrected it. 

But again getting new error as

'Eigenvalue SUBCASES or acceleration loads exist,

  and all referenced material densities are zero.'

i have given the density of a material as 5.0e-09

Altair Forum User

Have you specified thickness in PSHELL card?

Altair Forum User

yes ...after giving the thickness now i got the answer. But still question remains as..

1. As i have imported .igs file,then still i need to give thickness in property of PSHELL? if dimensions of the rectangle is 25*10*3000, then which dimension should i give as thickness.?

2. i have done the similar analysis by taking cylindrical rod of 100 mm diameter and 1000 mm length. At that time i used PSOLID property and in this case i am using PSHELL. Why it is like this??

Altair Forum User

PSHELL is for shell elements and you have to define shell thickness.

 

since you have meshed the model with shell elements you need to give a shell thickness.

 

Otherway is mesh the surface model with solid elements and use PSOLID.

Altair Forum User

Modal analysis is all clear now.

Thank u Prakash sir.