X is not monotonic

[Hussain2339]

Deal all

I am simulating a 4-point bending test. When I Try to X and Y data, I receive the message that the X value is not monotonic and the interpolation is under-defined

How to address this issue

?

 

[NRP99]

The x values should be increasing for the data to be plotted by the Abaqus. E.g. if data(x,y)=(0,0),(1,1.5),(1.5,3)...and so on. Notice the values of x in data points is monotonically increasing(0,1,1.5...). If the values in X column is decreasing in any of the x data point from prior x data point value, Abaqus gives above error. Check your x column data for this.

 

[Hussain2339]

Yeah, it has the same issue. Can I delete it, I mean, is it allowed considering the rules of FEM to delete irregular data?

 

[NRP99]

From ODB you cannot delete, since ODB is read only. For XY data, off course you can delete since its temporarily extracted from odb. You can call whichever data you need for preselected sets before solving by using field output manager. Its not clear what is your objective.

 

[FEA way]

What exactly do you want to plot ? A stress-strain curve ?

 

[Hussain2339]

A Stress~Diplacement Curve (or strain whatever)

 

[FEA way]

It should work if you follow these steps:
- find some representative elements from which the stress and strain should be extracted
- use the tool to create XY Data from field output
- use the tool to operate on XY data, select the combine operation, add strain then stress XY data

 

[DanStro]

I find that this might be the most frustrating error that I commonly get in Abaqus. The only sure-fire way of 'fixing' it is to manually delete the duplicated time steps from the XY data sets. It's just so stupid but I've even gotten this when I have the individual fields created in the same Output Request in the CAE, ugh.