Integration points

Altair Forum User

Hello,

 

for a certain element type in Hypermesh I am able to switch between 1st and 2nd order. Is it possible to set also reduced integration for a chosen element, or to prescribe the location of the integration points?

 

Thanks for all information,

Matej

 

Rahul Rajan_21763

It depends upon solver.Which solver you are using?

 

Regards

Rahul Rajan | Hyperworks Specialist

www.altairhyperworks.com|rahul.rajan@altair.com

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Altair Forum User

I am using Optistruct.

Rahul Rajan_21763

In Radioss solver you can change Integration point in property card.What type of analysis you are trying at your end?

 

Regards

Rahul

Altair Forum User

Well, it is not directly connected with a specific type of analysis. I am just trying to understand the basics.

Which property card changes integration points in Radioss? Is it also available in Optistruct?

 

Best regards,

Matej

Rahul Rajan_21763

OPTISTRUCT is for linear and non-linear structural problems. It employs implicit integration schemes for static and dynamic problems.

RADIOSS is a explicit finite element solver for crash and impact simulation. It is equipped to solve complex non-linear behavior with a multitude of material and failure models.

 

In Radioss all property card allow change in integration or formulation to carryout explicit analysis.

 

https://altair-2.wistia.com/medias/wccd1xy5bu   When to go for explicit code ( Free Radioss Ebook)

 

 

Altair Forum User

Dear Rahul,

 

I would like to have somee questions related to elements in Optistruct.

Is that correct: the first order hexa element in Optistruct is a reduced integration element 'one integration point. Viscous hourglass formulation with orthogonal and rigid deformation modes compensation (Belytschko)'?

 

And the second order hexa element in Optistruct is 20 node brick element with 27 integration points?

 

Thank you.

 

 

Best regards,

Huynh NGUYEN

Altair Forum User

HI @Huynh

 

PSOLIDX 1st order is a reduced integration with 1 integration point.  Where as  Quadratic 20-node solid, full integration, variable number of Gauss points.

 

Altair Forum User

Thanks Prakash.

In manual of Optistruct it was written that PSOLIDX is only available for Geometric Nonlinear Analysis. In the case I run linear simulation, there are only two choices for Hexa element: one is first order and other is second order. Is it correct:

   - That first order is 'one integration point; Viscous hourglass formulation with orthogonal and rigid deformation modes compensation (Belytschko);

   - and  that second order hexa element is 20 node brick element with 27 integration points, because for linear simulation we can't define the number of integration points.

 

Best regards,

Huynh NGUYEN

Altair Forum User

Hi @Huynh Correct PSOLIDX is valid for geomertric non linear analysis and it is of no use in Linear static.

GAJENDRA KUMAR NHAICHANIYA

Hello,

Having same doubt, but answer is not cleared. Plz answer.

 

1. In Radioss i can change the number of integration point but in Optistruct we can't, so what default integration points (Full or reduced integration scheme) we have in optistruct ?

Altair Forum User

Hi @GAJENDRA KUMAR NHAICHANIYA

 

Can you let me know for what type of analysis you are using solid elements?

 

PSOLIDX is supported only for NLGEOM, IMPDYN, EXPDYN analysis types and you can activate PSOLIDX from PSOLID property.

 

Also, you can change the integration point scheme on PSOLID property. Please check ISOP under PSOLID property on OptiStruct help. 

GAJENDRA KUMAR NHAICHANIYA

Hi,

Very Thanks for reply.