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Restraints: How to model a hinge support point?
Hello,
this is my first try of SnS, I just wanted to check how it works and whether it is suitable to my needs.
I have modelled a simple I-beam with two eyes at the ends (pivot bearings) and one eye in the middle (point load).
How to declare that the restraint is fixed in x, y and z directions, but has released rotational degree of freedom about z axis?
Why there are only three degree of freedom to edit instead of six (3 translations and 3 rotations)? See 01-restraint-example.jpg.
In my given example results were as if the ends of the beam were fixed, not merely simply supported.
Please give any idea to model it properly.
I have chosen "Principal tension / compression" for my output, (see 02-choice-of-output.jpg) but when I generated html report it contained only deflections and von Misses stresses. How can I declare what output should the report contain?
Thank anyone in advance for help.
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Replies to This Discussion
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Permalink Reply by Michael Freytag on
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Hello Jacek,
I'll work up an example for applying rotational restraints using a geometry similar to yours.
As for getting the report to generate additional outputs, you have to modify the report template as described here:
http://www.intact-solutions.com/sns_documents/sns_2014/reporting.htm
You need to add the following line to the report template:
##SCREENSHOT SOLUTION PTC~Michael
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Permalink Reply by Jacek Godlewski on
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Hello Michael,
thanks for report tip.
Meanwhile, I managed with restraints as shown on attached picture, and got good results
Maybe there is a better solution?
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Hello Jacek,
That looks like it should work fine, there is still some resistance to rotation due to the Z-restraint on the bottom face, but the face is probably small enough it won't affect the behavior a lot.
Here's an approach that allows free rotation of the ends and provides a decent approximation of what you are trying to model:
If you are not concerned about the symmetry of displacement, you can also apply loads that are in static equilibrium and apply an edge restraint somewhere to ensure numerical stability. Here a 2000 N load is applied up, two 1000 N loads are applied down:
The displacement field will not be symmetric:
But the strain and stress fields will be symmetric:
~Michael
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Hello Michel,
thank you for help. Slowly I began to get a point how to manage with lack of rotational degrees of freedom at restraints.
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