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ramesh.5s
Posts: 8
Registered: ‎02-24-2011
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Correlation of moldflow simulation results with real measurement

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09-11-2012 12:34 AM

Dear Moldflow Users,

 

           I am doing moldflow simulation on clutch master cylinder body which is of Technyl A218 V30 material.It is a cylindrical component with 4-5mm thick, height around 150 mm, outer diameter will have two flanges and inner diameter will vary along the height from 24 t0 15mm. Kindly imagine the part.

           The objective of the project is to correlate the deformation (inner diameter) results of simulation with the real measurement.The simulation result shows much deaviation from the real measurement. This is because the measurement in real is taken in room temperature. But in moldflow simulation I have specified the cycle time as 50 sec. At the end of this cycle time the part has a temperature range of 70 to 130 deg C.

 

My doubt - Is it possible to bring the part to room temperature in the mold flow simulation.
                  In real, around 150 C the part get ejected and sourrounding air cools the part to room temperature.
                  We have to bring this effect inside moldflow simulation.

 

Process parameter
As in real
     Mold temperature - 80 C
     Injection temperature -295 C
     Injection time - 0.81 Sec
     Injection pressure - 894 bar
     Packing time (profile)- 11 sec
     Packing pressure (profile) - 500 bar
Assumed
     coolant inlet temp - 65 C
     cycle time   - 50 sec

 

Thanks and Regards

Ramesh

 

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Valued Contributor
Posts: 62
Registered: ‎08-25-2008

Re: Correlation of moldflow simulation results with real measurement

09-11-2012 01:03 AM in reply to: ramesh.5s

Moldflow warpage is supposed to predict the shape of the particle at room temperature after cooling.

 

Either there is something wrong with your setup of the simulation or Moldflow software does not work for your settings very well.

 

Just a few common sources of simulation errors:

  • Have you adequately inputted packing profile/cooling time (never use the defaults!)?
  • Have you inputted filling profille?
  • Is your V/P transfer realistic?
  • Have you modelled runners (sometimes modelling the barrel and injectors of the injection molding machine helps)
  • Have you modelled all the significant features of the part?
  • Is your mesh correct (low aspect ratios, no intersecting elements, etc.)?
  • Have you modelled cooling?
  • Do you measure moldings after the number of shots is enough to have the mold in the steady-state conditions?
  • Is you material shrinkage-tested? (for 2.5D)
  • If the polymer is water absorbing (like PA6, eg.) have you dried it enough?
  • Does the plastication is good for the part (the air shot is clean and does not need much pressure)?
  • Is the injection pressure predicted well? 
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Board Manager
raalteh
Posts: 232
Registered: ‎04-14-2009

Re: Correlation of moldflow simulation results with real measurement

09-11-2012 04:30 PM in reply to: ramesh.5s

Hi,


What Alex says is correct; the warpage results that Moldflow predicts are at room temperature, so it is already taking into account the cooling down from 'right afte ejection' to room temperature.

 

There is a longer explanation how it is done, but I'll spare you those details.

 

Hanno

Hanno van Raalte,

Product Manager for Autodesk Simulation Moldflow products
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