Dear everyone,

I try to run one case study that I got from Abaqus Verification Manual (4.1.37 Vumat : Rotating Cylinder).

But it doesn’t work, it always show an error ‘Node set assembly__m22 has not been defined’.  

Can anyone please tell me how to fix this error?

Modelling high temperature behaviour of intermetallic alloy with Abaqus: Hi,      I'm working on modelling the behaviour of an intermetallic alloy at high temperatures i.e. 700 - 900 oC. One of the curves generated from a uniaxial tensile test at 800 oC is attached. There is a sharp drop in stress after yielding before plastic deformation occurs.      Does a continuum constitutive law exist that might be able to model this in Abaqus?       Any help is much appreciated. Thanks.       Eoghan

Hi,

Hi,

I'm working on modelling the behaviour of an intermetallic alloy at high temperatures i.e. 700 - 900 oC. One of the curves generated from a uniaxial tensile test at 800 oC is attached. There is a sharp drop in stress after yielding before plastic deformation occurs.

Does a continuum constitutive law exist that might be able to model this in Abaqus?

 Any help is much appreciated. Thanks.

 Eoghan

Dear All,

My name is Ronald, student at Eindhoven University of Technology, master Structural Design and i have an import question about the FEM programme Abaqus, about orthotropic materials.

I defined an orthotropic or anisotropic material in Abaqus by using the option; engineering constants or orthotropic (all linear elastic).

Abaqus asks for the modulus of elasticity in direction 1, 2 and 3 and the shear modulus and poisson ratios.

So far so good.

But, i define a local material orientation, let's say 45 degrees, what is than the modulus of elasticity, shear modulus and poisson ratio.

A combination of experiment and theory shows that dielectric elastomers exhibit complex interplay of nonlinear processes. Membranes of a dielectric elastomer are prepared in various states of prestretches by using rigid clamps and mechanical forces. Upon actuation by voltage, some membranes form wrinkles followed by snap-through instability, others form wrinkles without the snap-through instability, and still others fail by local instability without formingwrinkles.Membranes surviving these nonlinear processes are found to attain a constant dielectric strength, independent of the state of prestretches. Giant voltage-induced stretch of 3.6 is attained.

Hello everyone,

I am currently working on a explicit simulation involving fixed timestep size.

Now say my simulation is 'x' seconds long and I want to have two different timesteps

1. from time 0 to y [timestep size 1]

2. from time y to x [timestep size 2]

x is the end time, 0 is the start time

where y is (0<y<x) .

I am using LS-DYNA. I want to incorporate this in the key file. I tried Define_Curve_Function keyword, but I do not have any success. Maybe i am doing it wrong. Any suggestion or idea would be greatly appreciated.

Cheers,

Lamboram 

Dear all,

Can someone suggest me literature where the problem "tensile stresses developed in an elastic body accelerated by an attractive body force" is discussed.  The situation is similar to finding the stresses developed in a celestial body falling into black hole (though my interest is in impact with adhesive forces).

The problem is about solving the inhomogeneous wave equation, where inhomogeneous part is due to the attractive force.  So any helpful hints in that direction will also be useful. 

Also, it is clear that tensile stresses will develop only if the attractive force has a gradient, since all the material elements of the body will accelerate uniformly otherwise (free-fall).

Thanks,

Hello All,

I am Master student of Computational engineering at Ruhr University
Bochum, Germany. Presently I have UEL Subrouitne implemented for 9 NODE
Piezo-Electric Shell Element .  I need to visualize the stress and
strain fields obtained from UEL Subroutine. I came accross "Creating
Contour Plots for UELs" in Lecture 6 Document of Abaqus Tutorial by DS
Simulia. There they achieve this by overlaying Dummy elements and dummy
materials. Has anyone tried this so far?
Would you also let me know, Should I have to write code to compute
stress and strains inside UEL subroutine manually and assign it to SVARS
at each integration points? I would greatly appreciate any little help.

Thanks and Regards,
Somu

Dispense cuscinetti

Hi there,

 I am trying to simulate a crack opening process in ABAQUS. I start up from a simple model of plate with a notch subjected to tension. I would like to see the crack opening. To model a brittle mnaterial behaviour I have added a brittle cracking with sub-option brttle failure and brittle shear.

Please look at dat file:

*Heading

  *Node

  *Element, type=CPS3

  *Element, type=CPS4R

  *Nset, nset=ASSEMBLY_PART-1-1__PICKEDSET2

  *Elset, elset=ASSEMBLY_PART-1-1__I1

  *Elset, elset=ASSEMBLY_PART-1-1__I2

  *Elset, elset=ASSEMBLY_PART-1-1__PICKEDSET2

  *Nset, nset=ASSEMBLY__PICKEDSET15

Hi all,

I'm trying to model high temperature viscoelasticity using hypoelastic constitutive equations. I'm not sure of how to include the rotation tensor in the generalized viscoelastic equation.

kindly advise me.

Thank you very much.

Hi all,

I'm trying to model high temperature viscoelasticity using hypoelastic constitutive equations. I'm not sure of how to include the rotation tensor in the generalized viscoelastic equation.

kindly advise me.

Thank you very much.

Hi all,

I'm trying to model high temperature viscoelasticity using hypoelastic constitutive equation. I'm not sure of how to include the rotation tensor in the generalized visco-hypoelastic constitutive equation.

Kindly advise me.

Thanks.

In many practical problems of solid mechanics, it is sufficient to characterize material deformation by the small (or linearized) strain tensor. But there are also many problems where the finiteness of strain must be taken into account. These are of two kinds: 1) Large nonlinear elastic deformations possessing a potential energy (exhibited, e.g., by rubber), in which the stress components are obtained as the partial derivatives of potential energy; and 2) inelastic deformations possessing no potential, in which the stress-strain relation is defined incrementally and the stress increment or rate must be formulated objectively (i.e., independently of coordinate rotations). The present paper reviews the latter kind.

How is the Almansi-Eulerian strain used?

Is there a way to use it with some form of static equations of equilibrium to solve small strain, large rotation problems? I have sucessfully applied the Green-Lagrange strain. But, I can't find anything on how the Almansi-Eulerian strain is used to formulate and solve boundary value problems.

Bower in Applied Mechanics of Solids talks about its use in constitutive models for large rotations. But, doesn't give a clue how to use it in equations of equilibrium to solve real-world problem. 

hi,

   i am new to finite elements, i may be wrong, wnen i was solving a problem of hanging beam and load applied at its free end for obvious reasons there was a displacement at the free end. when i increased the no. of elements, deformation was minimum compared to previous result. does this actually mean stiffness got increased? as the basic thing about stiffness is that it depends only on geometry, material property and boundary conditions which were all constant in my case. alll i want to ask is, does stiffness depends on no. of elements? 

thanks

while carrying out a simple 2D analysis of welding of butt joint considering the source of constant heat flux and applying it at certain nodes as constant heat flux, i encountered a problem that it says that the temperature at particular node is exceeding the pre set limit and no solution is obtained. I am a freshman in Ansys so any help in this regard will be helpful