Simulation isn't converging

Lara Gonçales · February 12, 2020, 13:08

I'm having difficulties to converge my simulation in the "Static Structure" and I don't know what else I can do.
I am simulating a deformation in the artery wall after simulating the blood flow in the Fluent. I am doing this through the "one way" method. So, I imported the pressure in "Static in the Structure" and started the simulation here, but it doesn't converge. The simulation stops in time 0.4 seconds.
I tried to refine the mesh (with an element size of 0.001 m), but nothing changed. I don't know if the property of the wall (density, isotropic, Yeoh equation) can interfere in convergence.
Can someone help me?

karachun · February 13, 2020, 04:08

Any pictures, error messages, models? Without additional information no one can help you. First of all it is good to tell what FEA package do you use.

Lara Gonçales · February 13, 2020, 09:22

Here is the image of the simulation result: https://imgur.com/cKj8GbS
I'm using ANSYS 19.1

I think the problem is the geometry I'm using

karachun · February 13, 2020, 10:16

Quote:

I think the problem is the geometry I'm using

Maybe, I cannot tell anything without geometry. Convergence difficulties are very common, they may be caused by zillion of reasons.
Some additional pictures descriptions (mesh type, mesh quality, boundary conditions, loads, material properties) will be fine.

Lara Gonçales · February 28, 2020, 09:24

Hey!
Last week, I tried to simulate again, but all the models did not converge. I don't know if the problem is the models or some incorrect configuration.
I have some images here about each setting.

https://ibb.co/6P7S6nv
https://ibb.co/Tg75wgG
https://ibb.co/FsQpHZj
https://ibb.co/B6gt8J3
https://ibb.co/F4WVHsz
https://ibb.co/mywDTZK

karachun · March 10, 2020, 03:06

Ok, but I still dont undersatnd - is this solid mesh or plate. If solid then try to reduceelement size - look like element size is bigger than wall thickness.
And try to reduce applied force. If force too big then any mesh will be distorted until solver diverge.

February 12, 2020, 13:08	Simulation isn't converging	#1
Lara Gonçales New Member Lara Andressa Ordonhe Gonçales Join Date: Jan 2020 Posts: 4 Rep Power: 6	I'm having difficulties to converge my simulation in the "Static Structure" and I don't know what else I can do. I am simulating a deformation in the artery wall after simulating the blood flow in the Fluent. I am doing this through the "one way" method. So, I imported the pressure in "Static in the Structure" and started the simulation here, but it doesn't converge. The simulation stops in time 0.4 seconds. I tried to refine the mesh (with an element size of 0.001 m), but nothing changed. I don't know if the property of the wall (density, isotropic, Yeoh equation) can interfere in convergence. Can someone help me? WilliamWoles likes this.

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February 13, 2020, 04:08		#2
karachun Senior Member Join Date: Nov 2015 Posts: 244 Rep Power: 11	Any pictures, error messages, models? Without additional information no one can help you. First of all it is good to tell what FEA package do you use.

February 13, 2020, 09:22		#3
Lara Gonçales New Member Lara Andressa Ordonhe Gonçales Join Date: Jan 2020 Posts: 4 Rep Power: 6	Here is the image of the simulation result: https://imgur.com/cKj8GbS I'm using ANSYS 19.1 I think the problem is the geometry I'm using

February 28, 2020, 09:24		#5
Lara Gonçales New Member Lara Andressa Ordonhe Gonçales Join Date: Jan 2020 Posts: 4 Rep Power: 6	Hey! Last week, I tried to simulate again, but all the models did not converge. I don't know if the problem is the models or some incorrect configuration. I have some images here about each setting. https://ibb.co/6P7S6nv https://ibb.co/Tg75wgG https://ibb.co/FsQpHZj https://ibb.co/B6gt8J3 https://ibb.co/F4WVHsz https://ibb.co/mywDTZK

March 10, 2020, 03:06		#6
karachun Senior Member Join Date: Nov 2015 Posts: 244 Rep Power: 11	Ok, but I still dont undersatnd - is this solid mesh or plate. If solid then try to reduceelement size - look like element size is bigger than wall thickness. And try to reduce applied force. If force too big then any mesh will be distorted until solver diverge.