tag:blogger.com,1999:blog-78087403848606661642023-11-15T11:13:36.843-05:00恋。家Unknownnoreply@blogger.comBlogger4125tag:blogger.com,1999:blog-7808740384860666164.post-42968816597607589192016-04-10T22:50:00.001-04:002016-04-10T23:01:22.156-04:00Instability resulted from the default extrapolation in ABAQUSThe default is LINEAR<br />
<br />
Turn off extrapolation of the displacement correction so ABAQUS does not approach a
sudden stiffness change too aggressively.
*STEP, EXTRAPOLATION=NO<br />
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In ABAQUS CAE, this can be changed in "Step" module (inside "other" tab).Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-7808740384860666164.post-10469740193547394902016-03-25T09:58:00.001-04:002016-03-25T12:19:30.042-04:00How to plot displacement over a length in Abaqus?<div style="background-color: white; font-size: 12.16px; line-height: 17.024px; margin-bottom: 0.9em; margin-top: 0.5em;">
<span style="font-family: Arial, Helvetica, sans-serif;">Create a path (Viewer-->Tools-->Path-->select points) by selecting nodes along the line you want to use as x-axis of the plot. Now extract xy data along that path (Viewer-->output-->create xy-data-->path).</span><br />
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<pre style="color: #222222; line-height: 24px; text-align: justify;"><span style="font-family: Arial, Helvetica, sans-serif;">To write the data to an ASCII file, use 'report'->XY data.</span><span style="font-family: verdana, arial, helvetica, sans-serif;">
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Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-7808740384860666164.post-58396046881769859092016-03-09T11:45:00.003-05:002016-03-09T11:45:22.057-05:00How to increase the attempt number per increment in ABAQUS?<div style="background-color: white; color: #333333; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 21px; margin-bottom: 10px; padding-right: 0px;">
Special thanks to <strong style="color: #999999;"><a href="https://www.researchgate.net/profile/Thomas_Ha3" style="color: #36a493; cursor: pointer; outline: 0px;">Thomas Ha</a></strong><span style="color: #999999;"> at Technical University Darmstadt</span></div>
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The default parameter of attempts per increment is 5. You can increase the number in CAE by clicking on:</div>
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Model ==> Steps ==> "Step-1" (or how you called the step after the initial step with the loads) in the model tree on the left with double-click</div>
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==> the menu bar on the top changes ==> click on "Other" ==> "General Solution Controls" ==> "Edit" ==> "Step-1" (or the other name)</div>
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==> "Specify" ==> "Time Incrementation" => "more" (the first of the three) ==> parameter "IA" ==> increase this parameter (in my calculation, I took 30)</div>
Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-7808740384860666164.post-23663489966172585162016-02-22T11:29:00.001-05:002016-02-24T23:25:29.565-05:00How to add random geometric imperfections in Abaqus?<span style="background-color: white; font-family: inherit; line-height: 21px;">Besides using eign-mode analysis, the following procedures are recommended by Dr. Yinning Lv:</span><br />
<span style="background-color: white; font-family: inherit; line-height: 21px;">(1)in your prepared .inp text file, find the *node part and copy this part into an Excel spreadsheet.</span><br />
<span style="background-color: white; font-family: inherit; line-height: 21px;">(2)for each node, you have initial imperfection of a prescribed factor;</span><br />
<span style="background-color: white; font-family: inherit; line-height: 21px;">(3) add this imperfection to the coordinates of *Node segment manually in the Excel spreadsheet.</span><br />
<span style="background-color: white; font-family: inherit; line-height: 21px;">(4) copy this updated *node segment to revise the original .inp file.</span><br />
<span style="background-color: white; font-family: inherit; line-height: 21px;">Now, it'll be ok to run this .inp file.</span><br />
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<span style="background-color: white; font-family: inherit; line-height: 21px;"><span style="font-size: 14px;">You can run inp file by following way:</span></span><br />
<span style="background-color: white; font-family: inherit; line-height: 21px;"><span style="font-size: 14px;">Open abaqus</span></span><span style="background-color: white; font-family: inherit; line-height: 21px;"><span style="font-size: 14px;">go to Analysis..create job...</span></span><span style="background-color: white; font-family: inherit; line-height: 21px;"><span style="font-size: 14px;">in source option ..give the path of your input file.</span></span><span style="background-color: white; font-family: inherit; line-height: 21px;"><span style="font-size: 14px;">then submit for the analysis..then</span></span><span style="background-color: white; font-family: inherit; line-height: 21px;"><span style="font-size: 14px;">After finishing the simulation.....go to results..then go to Output database</span></span><span style="background-color: white; font-family: inherit; line-height: 21px;"><span style="font-size: 14px;">select ODB file which generated during ur simulation.</span></span><br />
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In addition to that you can import inp file by this way.<br />
Go to file<br />
import..model<br />
pop up file filter select inp file..then ok.<br />
Yourinp file will be imported in abaqus.<br />
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Right click "Models" - the parent of everything in model tree, then select import in the sub-menu. It should open a window, choose the filetype as "Abaqus input file, .inp". The window should now display all the input files in the working directory. Select your input file, this should import the model. </div>
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You may then run by creating a new job and submitting the job.</div>
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<span style="background-color: white; font-family: inherit; line-height: 21px;"><br /></span>
<span style="background-color: white; font-family: inherit; line-height: 21px;">A. Papa and S. Pellegrino, Systematically Creased Thin-Film Membrane Structure, Journal of Spacecraft and Rockets, 45, 2008:</span><br />
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<span style="font-family: inherit;">Geometric imperfections were seeded into the model to facilitate
the formation of buckles (wrinkles). Random imperfections z were
seeded [8]
</span><br />
<span style="font-family: inherit;">z=k*pi*h, (i=1, . . . , N)</span><br />
<span style="font-family: inherit;">where k is a dimensionless amplitude parameter, pi is [-1, 1] a
pseudorandom number, h is the membrane thickness, and N is the
total number of nodes in the model. A MATLAB script was written to
generate a table of nodal geometric imperfections that were
subsequently superposed to the heights of all of the nodes of the finite
element model. The value k= 0.2 was used. </span></div>
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