Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Abaqus 6.14 CAE - Imperfection Study

Status
Not open for further replies.

benperryman

Mechanical
May 9, 2015
2
The title of the project is as follows:
A study of the effect of imperfections on the buckling capability of a soda can under axial loading.

My group and I are aiming to carry out the following:[/li]
[li]Linear buckling analysis of soda can to gain first 5 eigenvalues[/li]
[li]Riks buckling analysis with plasticity and the introduction of imperfections in the form of wall thickness[/li]
[li]Riks buckling analysis with plasticity and the introduction of imperfections in the form of out-of-roundness[/li]
[li]Experimental analysis on an Instron machine to compare with results gained on Abaqus CAE[/li]

The following steps were carried out for he linear buckling analysis:
[li]Create part (Shell, extrusion)[/li]
[li]Apply material properties and section[/li]
[li]Mesh – Sweep[/li]
[li]Sets of up and down slave nodes with master reference points[/li]
[li]Steps – Linear perturbation, Buckle[/li]
[li]Apply constraints, BCs and load[/li]

The same was then carried out for the Riks analysis with the following changes:
[li]Add plasticity values for material using true-stress strain curve[/li]
[li]Steps- Riks, static step[/li]
[li]Load is set for that to be equal to first buckling load (-2554.5 Pa)[/li]
[li]Apply load equal to that of the first buckling load[/li]
[li]Introduce imperfections using edit keywords window[/li]
[li]
Max deformation from linear buckling analysis normalised (1/1.092E-03)[/li]
[li]
Multiply by thickness (0.097E-03)[/li]
[li]
Multiply by 0.1 for 10% imperfection, 0.2 for 20% and so on[/li]

Using the edit keywords window, I typed in what's shown on the attached image (where Buckle_load are the results from the linear analysis)

We are now stuck on how to compute the imperfection in terms of out of roundness. Any suggestions would be much appreciated!

 
Replies continue below

Recommended for you

The following was typed in the edit keywords for the linear buckling analysis:
*NODE FILE
U

The following was typed in the edit keywords for the Riks method:
*IMPERFECTION, FILE=Buckle_load, STEP=1
1, 0.010591
2, 5.2953E-03
3, 2.6477E-03
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor