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# Some problem with Stress Analysis

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I have to do a load simulation for a steel structure frame, and I am using a software called Autodesk Inventor. The strange problem is that Im having a hard time to understand the analysis result. The simulation bend a 50x50x3mm square shaped "steel bar" with a force of 5N, to me, that does not make any sense, the force involved to break these thing were in the magnitude of kNs. 5N suppose not make any visitable deform in the geometry. The following images includes some details of the result:

The steel frame bend 10degree just under 5N of force applied at top

To make sure I didn't do anything wrong, I redo the experiment with only earth gravity applied, and this can't be possible.

I double checked the mechanical properties for this material, the Yield and Tensile Strength were numbers form catalog, I didn't touch the rest of these values. If you know what they mean, feel free to explain.

So, if any of you are professionals in this field, please tell me what I had done wrong or give some link to useful websites. Your help will be deeply appreciated.

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How long is it? Double check the data.

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How long is it? Double check the data.

The length is 350mm, its in proportion with the rest of dimension given in the picture.

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Refering to Wikipedia: Deflection (engineering) gives a simple equation for end loaded cantilever beams. Go back into Inventor and futz about until you duplicate an answer on screen with the performance the equation says to expect. If you have way too much deflection then your span is much longer than you think or the elasticity or area moment figures are off by orders of magnitude.

Oh, and double check what the defined value of gravity is in Inventor!

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Thanks Grames, I think I solved this problem, its actually kind silly. I did not closely exam those equations on Mathhailno, but it does remind me something about that color bar, the maximum stress was 1.2Mpa something, and in contrast to the 200Mpa yield strength, there should be no actual deformation. The computer did it correctly, so it has to be a problem with software setting.

First, I change the material setting to plastic and conduct the same experiment. The result indicate the same deformation occurred with plastic, so I am sure the problem must caused by the software. Then I read the help file, I found that this is a feature of the display setting, the current result is showing an exaggeration. After I switched to the realistic deformation, I run the simulation again with steel and plastic with an applied force 1000N. No visible deformation occur on the steel bar and the plastic bar bend, this makes scene.

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