Use BeamAdapter model for a Mesh Topology given

[Hoangn06]

Hello everyone,

I want to ask if anyone knows how to use the BeamAdapter model for a given edge mesh.

I have a beam mesh in the form of an .msh file. I want to import this mesh into the scene and choose the parameters for that mesh (Young's modulus, Poisson's ratio, radius of the beam, and mass) using the BeamAdapter Plugin. My simulation will only involve mechanical tests on that beam (such as tension tests, flexion tests, compression tests, etc.), so I am only interested in the "Mechanical" feature of the beam. I am not interested in the "deployed" feature of the BeamAdapter.

In every example shown in the plugin, it seems to me that the beams are created and set up to be deployed only, and there is no example showing how to import a mesh and choose its parameters and do the mechanical tests on the mesh.

Can someone show me an example how to this?

I have a simple edge mesh for example if someone need to test it out: https://drive.google.com/drive/folders/10mTxqnopmDWp9XwhVaeLkIpDqUQoVMET?usp=sharing

Thank you everyone and have a nice day!

[Hoangn06]

Hello everyone,

I've tried to create the simulation with BeamAdapter with the script below with a mesh topology msh imported.

The problem is the scene of the simulation is weird and the beam is also weird and deformed showed in the 2 photo under here:

While the beam which is a line looked like this in the GMSH:

Why is the mesh in SOFA different from the initial mesh? The mesh in SOFA is deformed in a strange way, and when I launch 'Animate', the mesh moves chaotically and disappears even though I haven't applied any forces or constraints.

Can someone please help me with this?

Thank you and have a nice day!

XML SCript ----------

<VisualStyle displayFlags="showForceFields" />

<DefaultAnimationLoop />
<DefaultVisualManagerLoop />

<MeshGmshLoader name="meshLoader" filename="Stent_beams/beam_0.msh" />

<Node name="BeamModel">
	<EulerImplicitSolver rayleighStiffness="0" rayleighMass="0" />
	<BTDLinearSolver verbose="0"/>

    <MeshTopology name="BeamMesh" edges="@../meshLoader.edges" />

	<MechanicalObject template="Rigid3d" name="WebModel" position ="@../meshLoader.position" showObject="1"  />
	
	<BeamInterpolation name="BeamInterpolation" radius="2e-6" defaultYoungModulus="5e+10" defaultPoissonRatio="0.3" /> 
	<AdaptiveBeamForceFieldAndMass name="BeamForceField"  computeMass="1" massDensity="6.5e+3"/>

</Node>  

-----

[alxbilger]

meshLoader.position is a vector of Vec3. When you do <MechanicalObject template="Rigid3d" position ="@../meshLoader.position"/>, you convert the position vector from Vec3 to Rigid3d. Therefore, I am not confident that the orientation part of your DoFs is correct.

[alxbilger]

Have a look on Vertex2Frame. I am not familiar with this component. It looks like it does what you want.

[Hoangn06]

@alxbilger Thank you for your suggestion. I tried to add Vertex2Frame but it seemed not working... Or maybe i am doing something wrong....

Here is the xml script for Vertex2Frame:

    <MeshTopology name="BeamMesh" edges="@../meshLoader.edges" />
    <Vertex2Frame name="Engine" position="@../meshLoader.position" normals="@../meshLoader.normals"/>

   <MechanicalObject template="Rigid3d" name="WebModel" position ="@Engine.frames" showObject="1"  />

   <BeamInterpolation name="BeamInterpolation" radius="2e-6" defaultYoungModulus="5e+10" defaultPoissonRatio="0.3" /> 
   <AdaptiveBeamForceFieldAndMass name="BeamForceField"  computeMass="1" massDensity="6.5e+3"/>

</Node>  

[Hoangn06]

@hugtalbot @alxbilger @bakpaul Does anyone know how to directly change the orientation of the axis to have the X-axis of each element in the same direction of the beam's tangent? Thank you...

[bakpaul]

HEllo, as said before, you need to engineer it. Build a script that rotates the quaternion and align them with the beam. There exists no script doing this for you in SOFA in my knowledge.

[Hoangn06]

Hello @bakpaul,

Thank you for the reply. I will try to build a script to rotate the element...