A dependent d.o.f. defined more than once in rigid element - error

Rahul_P1
Rahul_P1
Altair Employee
edited October 2020 in Community Q&A

'Dear Altair,

I have a problem with my model, and don't know how to solve it. I have an error message: 'A dependent d.o.f. defined more than once in rigid element', however these are shell elements.
Could you please help me what should I do? '

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Answers

  • Rahul_P1
    Rahul_P1
    Altair Employee
    edited November 2014

    Apart from shell elements you have rigid elements representing bolts int he model you have sent us, and here you have several dependent nodes that connect to pre-existing dependent nodes i.e. you cannot have two rigid elements connected to a single dependent node.

    Below is an image from your model, it is always necessary to check the dependancy from the check elems panel as shown.

    ojja3-Capture.JPG

    Since it is perhaps cumbersome to redo your rigid elements, you might consider reversing the nodal dependencies from dependent to independent.

    To avoid double dependency issues with rigid elements, their dependent degrees-of-freedom may be converted to independent degrees-of-freedom when conversion is necessary for the model to run. This conversion can be used if the dependent degree-of-freedom of a rigid element is a dependent degree-of-freedom of another constraint equation (may come from an MPC equation or another rigid element). This conversion from dependent to independent degrees-of-freedom is done automatically when PARAM,AUTOMSET,YES is specified in the input data

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