Simulation report

[mathieuD8XG3]

Hello,

I have a simulation of a staircase with holes in the baseplate for bolting to the floor. There are a series of holes and depending on the position there will be a negative or positive reaction force.

I would like to create a report that displays the reaction force of each individual hole.

When using the Inspect > Reactions i can select the face of the hole giving me the reaction force i need. But upon selecting multiple holes (with positive and negative reactions) i can only get the sums of the reactions and not for each hole individually.

For calculating the required anchors i need to report the reactions in each individual hole.

Selecting one hole gives me the information i need (Z component of the force)

Selecting multiple holes gives me the combined reaction force of the hole but i need the information of each hole individually:

Baseplate with al the holes:

Total view:

[henderh · Accepted solution]

Hi @mathieuD8XG3,

Thank you for providing the detailed background info + screenshots.

As you've discovered, the reactions in the report are listed per constraint, however there's a workaround.

I realize this is now a bit inconvenient with so many holes, but if you could apply a unique / independent constraint per hole, after re-solving, the report should then display the reactions per hole independently.

Hope this helps! Please let us know if you have additional questions, comments or suggestions.

Best regards,

[mathieuD8XG3]

Thank you, this works out for me.

Just to be sure, when the Z component of a reaction force is positive, is this upwards (=the constraint wants to be lifted up) or downwards( =the constraint wants to be pushed down)?

In our example the constraints of the holes will be anchored with bolts to the floor, so i want to be sure if the reaction force wants to pull the bolt out of the floor or it will be pushing down on the floor.

[henderh]

Hi @mathieuD8XG3,

If I understand correctly, when the Z component of the reaction force is positive, it is upwards (since the Global +Z direction is upwards for the staircase model in the screenshots). i.e. the upwards reaction force is "pushing back" against the downward (-Z direction) force from the applied load(s). Therefore a positive Z reaction force indicates it wants to be pushed down on the floor (and vice-versa).

There are additional details contained in our online product documentation, which includes a blurb on how reaction force values can be leveraged to determine if bolt strengths will be adequate:

• https://help.autodesk.com/view/fusion360/ENU/?guid=SIM-REACTION-FORCE-VIEW-CONCEPT
  • Spoiler

    Using reaction force results

    The reaction forces in a particular direction should be equal in magnitude and opposite in direction to the total load applied in the same direction. Therefore, you can check reactions to verify that the model setup is correct. The contour plot shows the individual reaction forces distributed along all constrained nodes. For example, assume a block of steel weighing 500 pounds rests on the floor. Only gravity is applied to the model. The bottom of the block is fixed to represent the support from the floor, which is not included in the model. The sum of the reaction forces along the bottom surface of the block should equal 500 pounds. 
    You can also use reactions to verify that any bolts, screws, or rivets used to mount a part are adequate for the task. For example, to simulate a part bolted into an assembly, you could use fixed constraints to represent the bolts (instead of modeling the bolts as solids). The reaction forces at the bolt locations should not be high enough to shear the bolts or to break them in tension. If the reaction forces exceed the bolt strength, then you need to specify larger or stronger bolts in your design.

[mathieuD8XG3]

Is there an option to indicate the position of the constaint more clearly? With an arrow for example?

[henderh]

Hi @mathieuD8XG3,

We can force the glyph size to be larger in the user preferences for sim, but we cannot change the color or indicate the (x,y,z) position more clearly in the report. I'm not sure why in the report I generated for the simple case, the constrained entities are highlighted blue, but I don't see it in your screenshots.

If you'd like to visualize which fixed holes are pulling vs pushing to balance the applied loads in static equilibrium, we can display the result type for the Reaction vertical component. In my example, blue-ish colors indicate this direction that we can use to visually scan the model.

Hope this helps!