Learning Forum

[1617836513]

I have selected a element, so how do I output the stress/strain at the integration point?

[Aurojyoti Prusty]

Hello,

It is true that the stress and strains are evaluated at the integration points, but the postprocessor does the averaging of those stress results to the respective nodes, called averagred stress values. Similarly unaveraged, elemental difference, nodal fraction etc. are available. But in Mechanical GUI, it is not directly feasible to have integration point/ Gauss point stress values.

Thanks,

Aurojyoti

[1617836513]

Hi，so if I want to know the stress at the integration point, do I need to calculate it manually using the relationship between the node stress and the stress at the integration point?

[1617836513]

Is there a unaveraged stress/strain that's closer to reality and more informative?Thank you!

[Aurojyoti Prusty]

Hi Shiyu,

Averaged stress refers to the smoothing of stress values across the nodes of the mesh. This is done by taking the stress values calculated at the Gaussian integration points within each element, extrapolating them to the corner nodes using the element's shape functions, and then averaging these values at each node that is shared by multiple elements. This process results in smoother contour plots and a single stress value per node, which can be easier to interpret, especially when the mesh is sufficiently dense to provide a mesh-independent solution.

Unaveraged stress, on the other hand, does not undergo this averaging process. Instead, it shows the range of stress values at each node, including the highest and lowest values that occur due to the different elements sharing that node. This can reveal stress discontinuities and may be more representative of the actual stress peaks, but it can also make the stress contour plots appear less smooth and more difficult to interpret.

The choice between using averaged or unaveraged stress results depends on the specific requirements of your analysis and whether you need to capture the peak stress values or prefer a smoother representation of the stress distribution. If there is a significant difference between the averaged and unaveraged stresses, it may indicate that the mesh density is insufficient in that region, and further mesh refinement might be necessary. You might want to see the below video for more information.

Specifying an Appropriate Element Size for Stress Analysis Using Ansys Mechanical — Lesson 1 - YouTube

I hope this helps.

Thanks,

Aurojyoti

[1617836513]

Thank you.