Interpreting stress data

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In this video, you’ll:

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identify stresses at a specific feature or region in the model,

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recognize and interpret expected data ranges and results when given a Results View,

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and determine appropriate stresses to display in the Results View.

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Once a simulation has been computed, you must extract useful information from the results data.

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Fusion 360 contains a plethora of tools for inspecting the results.

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The process of going through output data and retrieving useful information is known as post-processing.

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Open the file Interpreting Stress Data.f3d in the Simulation workspace and then solve the study.

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After the study has been solved, from the Browser,

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right-click Results and from the shortcut menu, select View Results.

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Here, a plot of the von Mises stress throughout the component displays.

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Von Mises stress can be thought of as the equivalent stress in any given element of the mesh.

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This is critical to understand that if the von Mises stress

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exceeds the yield strength of a material, then it will undergo plastic deformation.

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That is, it will change shape permanently.

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Conversely, if the von Mises stress is below the yield strength, it will return to its original shape.

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For example, on the legend, you can see that the maximum von Mises stress is 145.8 Megapascals (Mpa).

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This is below the 207MPa yield strength of mild steel.

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Therefore, elastic deformation is expected.

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Click and drag the measures of the legend to isolate materials between ranges of stress.

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You can see where the peak stress occurs both in the color on the model,

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and by using min/max probes.

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These probes can be activated from the Toolbar.

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By default, Minimum and maximum probes already display on the model.

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To inspect the stress in other regions, you can create your own probes.

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Expand Inspect.

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From here, you can choose to place other probes on the model.

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For instance, Point Probes display the X, Y, Z values of a position in the global coordinate space.

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Surface Probes display study results on the mesh surface.

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For now, select Create Surface Probes to open the Create Surface Probes dialog.

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In the canvas, zoom in on the model and pick to place probes on areas of interest.

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As each probe is placed, the stress value for it displays.

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Once you are finished placing probes, in the dialog, click OK.

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Conversely, you can delete probes that were already placed.

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From the Toolbar, expand Inspect, and select Delete All Probes.

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The newly created probes are deleted, but the Min/Max values remain.

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If the stress inside the component is of interest,

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you can slice through the model to review the interior.

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Again, expand Inspect, and this time, click Create Slice Plane.

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The Slice Plane dialog displays.

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In the canvas, select a reference plane, such as a surface on the side of the model,

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and then drag the arrows to position the plane.

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As the plane moves, the internal stress displays in both the dialog

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and in the canvas on the context menu.

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In the dialog, click OK.

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Once finished, you can toggle the slice planes off.

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In the Browser, expand Results, and then expand Slice Planes.

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Deselect Slice Plane:1.

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The slice plane is now suppressed and is no longer visible in the canvas.

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In addition to von Mises Stress, you can view other types of stress applied to the model.

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From the legend, expand the Von Mises drop-down and select 1st Principal.

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This will denote the tension throughout the model.

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Now, change the stress type to 3rd Principal, which denotes compression.

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Now, change the metric entirely to view the safety factor of the material.

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Expand the Stress drop-down and select Safety Factor.

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The safety factor is calculated as the yield strength of the material,

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divided by the von Mises Stress experienced at any individual element.

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If the safety factor is above 1, elastic deformation is expected.

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If the safety factor is below 1, however, plastic deformation is expected.

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In this example, the legend displays the safety factor minimum as 1.42,

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so there is no expectation of plastic deformation.

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Expand the metric drop-down again and select Displacement.

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Here, you can see that the peak displacement

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occurs at the top of the face receiving the vertical loading, equaling 1.865mm.

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As you can see, the model has exaggerated this displacement for reasons of clarity.

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However, this scaling can be altered.

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From the Toolbar, Deformation panel, select Actual.

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The canvas updates.

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Select Adjusted to return it to its original state.

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Lastly, to help visualize how the part deforms under load, you can animate the deformation.

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From the Toolbar, in the Result Tools panel, select Animate.

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The Animate dialog displays.

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Expand the Speed drop-down and select Fastest.

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Then, enable Two-way.

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Click Play and review how the part deforms under load.

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When you’re finished reviewing the results, save the file.