ABAQUS/CAE

Help needed!! in Abaqus

I have UMAT written to update stress and material tangent components for a user defined material model. I need stretch ratio as an input for my material model. For this I am using deformation gradient from UMAT. Problem is, when there is constant strain (strain rate = 0), for example when material stretched to 100% strain (rubber) and then held at that strain for certain time to see stress relaxation, the deformation gradient should give the same value of 100% strain, but to my surprise this is changing. Can any one help me with this.   

Greetings all,

i want to know, is there any way to measure edge length ( "curves" specifically,  not looking for straight edge length  using distance between vertices as query feature :) ), and also to get vertices co-ordinates in  local co-ordinate system; in ABAQUS CAE or using python scripting.

my problem is somehow related to above query,  can manage solution with 'other' tricks, but want to know any standard methods are avaliable.

Any help is appreciated.

Thanks,

siddhesh 

I am trying to find the rate of crack growth in steel beam under fatigue loading using ABAQUS... i am having trouble with the loading part.... How to provide cyclic loads in ABAQUS...and obtain the increment in crack length with time??? Please help

I am simulating a cube of sides 10 units. I have applied the
load as pressure of 16 units at top. The cube is meshed by usign a
global seed size of 5. It means, there are 9 elements and 27 nodes
(using C3D8R). I have used the material property of steel for instance.
The base of the cube is fixed and the sides are allowed to move
vertically.  Now i want to calculate the nodal force at the centre of
the cube i.e. at the centroid of the cube (not in the centre of any of
the exterior sides). 

Well I tried to search for a related thread and could not find one, so creating a new
one. But if such a thread exists, please direct me there, thank you. I

I have modeled a pile which was made to penetrate at a constant rate (Displacement controlled loading) into the soil. The steps were divided into geostatic, contact and Applied load steps. After the program runs successfully, i am facing difficulty in extracting the results.

 I want to plot the load vs. displacement curve at the bottom of the pile.  After i have summed up all the nodal forces at the bottom of the pile, the total load was coming quite less as compared to the applied Load/Displacement.

How to differentiate between the analysis of a "hollow pile with closed top and an open end" with "vented top and open ended pile".

After applying compressive load at both the pile tops (closed and vented), i have obtained/observed that the vented pile is offering higher resistance to penetration as compared to closed top pile.

Hello,

Hi,

I am trying to perform a response spectrum analysis of a tall tower. I work with abaqus 6.10, but i am unsure of how to define a spectrum. there is no spectrum radio button on the create amplitude menu... so i guess i have to edit the keywords.

does anyone have an example of how a spectrum can be defined? i'd be much grateful

Regards,

Lekshmi Remesh 

Hi,

I have used XFEM in Abaqus for static analysis. I use traction-separation cohesive behavior with XFEM.

I want to use XFEM in implicit dynamic analysis. I am using Abaqus version 6.12. As far as I know xfem was allowed only with static analysis in earlier Abaqus versions (6.9). I read that the newer versions have implicit dynamic analysis compatiblity with XFEM.

Dear all

I am trying to plot the dispersion curbve for wave propagation in an ALuminum beam under S0 and A0 lambwave.  My simulation has completed and I thin the results are reasonable as long as visualization is concerned.

I am trying to plot dispersion curve for these two waves using Abaqus outputs. As far as I know I need to use Abaqus outputs such as displacement or velocity for calculation of wave speed.

1- How would I calculate wave speed by Abaqus outputs and is this calculated wave speed the phase velocity or group velocity ?

Hey,

I am trying to mount a piezoelectric actuator(PZT) on a plate. The PZT is rectangular and I have created a tie constraint between a surface on the bar and one of the PZT's surfaces. How do I put the PZT at a certain location on the bar in the assembly? I am assigning a coincident point position constraint between a point on the bar and a point on the PZT, is that sufficient? Thank you.

Regards.

Hi Everyone

 I just started using ABAQUS. I was trying to plot a graph for stress vs
strain for a simple problem, plate with a hole. I could use some help
here. Really appreciate it if anyone could help me with the steps.

 Srinath

Hey all, 

The PDA model implemented in Abaus is an implementation of the idea of the cohesive zone model (CZM), which is quite popular for the analysis of delaminations, but PDA is for intralaminar damage. The problem my group faced when trying to use PDA was "where do we get the material parameters?"  We asked around in blogs and such but could not find a definitive answer. So, we went to work and came up with a methodology that may serve you.

Hello,

 I am new to the FSI interaction module in abaqus, i wanted to know how to go for it, as i have modelled structure embedded in the soil domain using abaqus standard /explicit model and on which i have to model fluid striking the structure as well as the soil layer i have to use only Abaqus CFD model , iam not sure how could i model fluid in the CFD model what kind of interaction in between abaqus standard and abaqus cfd model and how could i make interaction, also how to install FSI module in abaqus cae?? it's knid of surge water striking structure!!

Thanks