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FAQ 004666 | Why is it not possible to change the solving method for the equation system of my model?
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First Steps with RFEM
Question
Why is it not possible to change the solving method for the equation system of my model?Answer
Basically, there are six methods available for solving the nonlinear algebraic system of equations. If your model does not include any nonlinearities (that is, you have created a purely linear system), the access of this selection field is blocked.
Figure 01 - System Without Nonlinearities
As soon as you define a nonlinearity in the model, the selection field for the solving methods is activated, and you can select the desired solving method.
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Dlubal FAQ Solving method Solving method of equation system Select solving method Solving method locked Frequently Asked Question FAQ about Dlubal Question and Answer about Dlubal
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New
Deactivation of Nonlinear Effects
If nonlinear effects are used in the model, it is possible to deactivate them in the global calculation parameters.
![Window '1.1 General Data' for Serviceability Limit State with Settings for Nonlinear Calculation According to [2]](/-/media/Images/website/img/000001-010000/009301-009400/009376.png?la=en-US&mlid=149164433F8D4E0D89705EF3B002E4A8&hash=A7B507AEAEECF2AA3900D4C7A837EC8C5A08ADFB)
New
Increased Calculation Performance by Reducing the Nodal Degrees of Freedom
The number of degrees of freedom in a node is no longer a global calculation parameter in RFEM (6 degrees of freedom for each mesh node in 3D models, 7 degrees of freedom for the warping torsion analysis). Thus, each node is generally considered with a different number of degrees of freedom, which leads to a variable number of equations in the calculation.
This modification speeds up the calculation, especially for models where a significant reduction of the system could be achieved (e.g. trusses and membrane structures).
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