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[Abaqus] Random LPF in Riks method

Submitted by Staszkinson on

Hello,

My model is simply supported I-shape S4R beam. 

Could anyone explain me, why Static Riks method with an *imperfection returns different/random results for the same analysis runned two and more times?

Let's say that I set maxium load proportionality factor = 160.

For the first time, the solver needed  13 increments to exceed the limited value.(LPF=162.69)

For the second time, the solver needed 23 increments to exceed the limited value.(LPF=164.403)

How can i get correct results? 

Modelling continuum based constitutive for adhesive layers with finite thickness

Submitted by mahzanjohar on
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I am new in ABAQUS. 

Can anyone help me on modelling continuum based constitutive for adhesive layers with finite thickness in ABAQUS?

 

 Is there is any tutorial in abaqus documentation about modelling the thick adhesive layer? I'm try to model thick adhesive layer in a single lap joint.

attached is the link of my model. can anyone teach me how to correct this model...

FE modeling of dispersion in cylinders

Submitted by HSD83 on
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As you may know wave propagation in circular cylinders is dispersive. As shown by Pochhammer, there

could be several different modes propagating in an infinite cylinder with

different wave speeds. I'm modeling wave propagation in a finite 3D circular cylinder in

abaqus impact analysis

Submitted by okok on

Hello

i have created a model in abaqus for dynamic impact, evrything is according to program`s help but it  does not work,

 about the model:

there are 2 parts in model, one is fixed and the other has velocity toward the first part,

the second parts comes near the first part but no impact occur,

 

could anyone help me to finish this and help me to understand why it doesnt work?(if  attache the model)

Viscoelastic model parameters in LS-Dyna

Submitted by HSD83 on
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I'm using elastic solid elements to model wave propagation in an
structure in LS-DYNA. I need to add the effect of dissipation in the
system by using viscoelastic material model (MAT_006). All I know from
my material is storage & loss modulus (E=E'+E"*i). I was wondering
how can I transform these parameters into G0, GI and BETA needed by
MAT_006 (G=Gi+(G0-Gi)*exp(-beta*t))?

Shear test data evaluation fail in ABAQUS

Submitted by Wei Ong on
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Dear all,



I am currently perform a curve fitting for material coefficient determination.

In my hand, i have a set of stress strain data from the shear test.

I try to import the data as planar test data in ABAQUS.

However, when i try to evaluate the material to get two term moooney rivlin coefficient out, it shows the following message.

"Material evaluation cannot be carried out with planar test data alone unless Reduced Polynomial, Arruda-Boyce or Marlow potentials only are used."



strain as linear functional

Submitted by sanderos on

Hello,

I am reading the book "Computational Methods for Plasticity" by Neto, Peric and Owen and one particular sentence is confusing me. At page 57 after (3.81) the book says "..it is worth pointing out that the infinitesimal strain tensor is a linear functional of the displacement vector field". Isn't a functional a mapping to one scalar value (as the total potential energy functional or the virtual work functional)? Could anybody help me out with that?

Thanks in advance 

[FEM] How we are using shell geometry properties in time of calculation?

Submitted by IvanKushnarenko on
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Hello.

I'm interested in methods and approaches for FEM, that are used for taking into account the shell geometry properties (curvatures, quadratic forms) in time of calculation. I'm not telling about NURBS, the shells are defyned by analytical expressions: sphere, Monge surfaces, Joachimstahl surface. In Zienkewich book they are use the flat elements, but in time of calculation they don't use the shell geometry, only for mesh generation. Maybe someone somehow have used in shape functions the coefficients of quadratic forms...

abaqus analysis (meshing)

Submitted by apin87@hotmail.com on
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may i know how to create extra element surrounding  the model in the meshing in abaqus?

in my case, i want have the extra inactivate element (with zero stress, strains condition) surrounding my model for the inital step, and then activate the element for the continuos step if neccesary...

 

thank you