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Error in fixed-fixed beam buckling analysis

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Hello sir,

While I am doing buckling analysis of fixed-fixed beam, during computation the following error occurs, "Eigen solver 1: The mass matrix is zero". I have applied axial compressive load by using two boundary load at the fixed-fixed end.

Please help me out in this issue. I have also shared the .mph file.

Regards, Vasudha Agrawal



1 Reply Last Post 13 ott 2020, 02:11 GMT-4
Henrik Sönnerlind COMSOL Employee

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Posted: 4 years ago 13 ott 2020, 02:11 GMT-4
Updated: 4 years ago 13 ott 2020, 02:12 GMT-4

If your boundary conditions are fixed-fixed, the object cannot deform. A load applied to a fixed constraint is ignored. My guess is that you want to model a situation where there is a fixed constraint in one end, and a guided no-rotation support in the other end. There are several ways to accomplish that, for example

  • By using a roller condition instead of a fixed constraint.
  • By replacing the fixed constraint with a rigid connector with appropriate constraints and loads
  • By modeling half of the structure, and use symmetry conditions.
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Henrik Sönnerlind
COMSOL
If your boundary conditions are fixed-fixed, the object cannot deform. A load applied to a fixed constraint is ignored. My guess is that you want to model a situation where there is a fixed constraint in one end, and a guided no-rotation support in the other end. There are several ways to accomplish that, for example * By using a roller condition instead of a fixed constraint. * By replacing the fixed constraint with a rigid connector with appropriate constraints and loads * By modeling half of the structure, and use symmetry conditions.

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