# How to get the force value of fixed wall

I simulate the floatings by using DCDEM, there are collisions between floatings and fixed walls, I want to get the force value of the wall, is it possible?

I would be grateful for any suggestions

Tom

• You can find some examples about how to get the force of fixed walls...

I invite you to navigate through the PDF files you can find in DualSPHysics_v5.0\examples.

One of those examples is DualSPHysics_v5.0\examples\main\01_DamBreak

• Hi, Alex

I am very sorry to reply to you so late. I understand and thank you for the approach.

Thank you so much

Best regards

Tom

• Hi @Alex, I would like to ask mu query regarding similar problem.

In DamBreak example, we are -

```<!-- Creating void where building is present .... -->
<setmkvoid />
<drawbox>
<boxfill>solid</boxfill>
<point x="0.9" y="0.24" z="0" />
<size x="0.12" y="0.12" z="0.45" />
</drawbox>

<!-- Creating faces.... -->
<setmkbound mk="1" />
<drawbox>
<boxfill>top | left | right | front | back</boxfill>
<point x="0.9" y="0.24" z="0" />
<size x="0.12" y="0.12" z="0.45" />
</drawbox>

<!-- Giving left face a different mk number, here mk = 10, so that we could calculate force on that face by using computeforces... -->
<setmkbound mk="10" />
<drawbox>
<boxfill>left</boxfill>
<point x="0.9" y="0.24" z="0" />
<size x="0.12" y="0.12" z="0.45" />
</drawbox>
<shapeout file="Building"/>

<!-- In computeforces command we need to give onlymk as mk + 10 i.e. onlymk:20  --> ```

Could you please confirm if my understanding is correct?

Thank you.

• Referring to above question, I would also like to ask a follow up question. Suppose, we are instead using a stl file of building. There we need to assign mk value to whole stl geometry. How can we then compute forces on that particular face?

Like for my case I have done -

```					<!-- Building -->
<setdrawmode mode="face" />
<setmkbound mk="1"/>
<drawfilestl file="building.stl" objname="building" autofill="false">
<drawscale x="0.001" y="0.001" z="0.001" />
<drawmove x="25.79" y="2.75" z="0.8" />
</drawfilestl>

```

Please let me know how can we achieve the same using stl?

Thank you.