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The relation between incompressibility and divergence-free?

Submitted by phdggg on Fri, 03/04/2011 - 18:52

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Hi all,

Release DOF of beam in Abaqus/Explicit

Submitted by xmcarreira on Fri, 03/04/2011 - 12:09

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abaqus explicit

Hello everybody,

I am trying to model a plate (shell elements) supported on rubber bearings and columns (beam elements) and I would like to know how to release rotational degrees of freedom at one or both ends of a beam element in Abaqus/Explicit.

Unfortunately, the keyword *RELEASE only works in Abaqus/Standard.

Thanks in advance for your kind help. Regards,

Calculation of stfness matrix

Submitted by glshyam on Wed, 03/02/2011 - 06:14

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I need complete stifness matrix of a pzt 5h material, I've values of elastic constants s11=21e-12m2/n & s33= 15e-12m2/n. how to calculate the other values??

Concrete beam with piezoelectric sensors in ABAQUS

Submitted by ozguryapar on Wed, 03/02/2011 - 00:51

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ABAQUS

piezoelectricity

Hello,

I am trying to model piezoelectric sensors on a concrete beam in ABAQUS. Since I am using brttile cracking model, I have to use ABAQUS / Explicit. But piezoelectric elements are not available in ABAQUS / Explicit.

In some papers I saw that the piezoelectricity modeling problem in ABAQUS / Explicit is solved by replacing it by an equivalent Thermo-Mechanical problem. Does anybody know how to accomplish this?

Do you have any suggestions? Are there any other ways to model piezoelectricity in ABAQUS / Explicit?

How to update the stress in umat when the load is constant?

Submitted by yoyo Li on Tue, 03/01/2011 - 17:02

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My friends

I'm working on a constitutive model using umat in abaqus. There is a problem and can be described generally as follow:

A constant load is applied on beam elements, however, the elastic modulus decreases as a function of the axial strain of the element and loading time. In another words, the modulus will decrease when the umat is called at DTIME. I used STRESS=STRESS+DDSDDE*DSTRAN to update the stress, however, the result shows that the STRESS, STRAIN and DISPLACEMENT don't change since beginning.

issues faced in spectrum analysis,sprs on ansys

Submitted by Suraj Mathew on Tue, 03/01/2011 - 05:38

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Hi to all,

Im a student pursuing my project under GE Healthcare. My problem is basically the analysis of the vibrations on a X-ray tube packaging ( a wooden pallet which is the base) using an electrodynamic shaker. I have tried following Ansys help guide to my fullest extent but still no breakthroughs. Listed below are the issues and doubts im facing:

problem regarding critical initial time step in poroelastic material during consolidation process.

Submitted by Xiaogai Li on Fri, 02/25/2011 - 11:09

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Vermeer and Verruijt (1981)

critical time step

Dear all,

I have a problem regarding critical initial time step in poroelastic material during consolidation process.

As we know, for implicit integration method, it's unconditionally stable. But for the consolidation of poroelastic material,

there is a critical time step t_critical derived by Vermeer and Verruijt (1981), this has also been inclued in the abaqus software (http://129.25.22.58:2180/v6.7/books/exa/default.htm).