Drilling operation and Thrust force calculation in ANSYS explicit dynamics
MAMIN219
Member Posts: 42
Respected sir @peteroznewman ,
After your Valuable feedback (ABOVE Discussion), I have started Drilling operation from one thesis which i am attaching here
In this above thesis , They have used structural steel NL as drill material and Aluminum 6061 T as workpiece. In this thesis they have used experimental method so I have referred this for drilling operation. Here above, for 60000 rotating speed ( angular velocity in RPM) and 200 * 12 =2400 mm/min feed rate. so actual time for drilling is 7.5 sec which is very comupatationly tough in explicit dynamics .So they have used 200 as factor multiplication is original 12 mm/min value .
Here my doubt is in experiment they have used 6000 RPM but in software they have used 60000 RPM Why?
In addition, Feed rate is 200*12 =2400mm/min but in ANSYS velocity is in unit with mm/sec and thesis sir has used 2400mm/sec which is little bit confusion for me. Is this correct if yes then have used 0.0006 sec end time
Please brief highlight on calculation of end time for drilling operation above.
while I am simulating this file in my PC I have found error of :"Time step Too Small"
Due too large file (Larger than 100 MB ) I am only attaching ANSYS 19.2 file with all boundary condition and mesh file. Please give your valuable feedback for validation of this.
In addition , They got 931.8 N Thrust force by taking Normal stress at bottom surface but only written in thesis like :
" the drilling tool diameter is 0.5 mm, therefore the thrust force is 931.8 N Can you please brief highlight on this
Here I am attaching My ANSYS 19.2 file for your reference. Please check this file and change if need and give feedback on my above mentioned doubt.
Once again Thanks for always share your knowledge with us and motivate us 😊.
With regards,
MIHIR AMIN
Best Answer
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peteroznewman
Member Posts: 11,054
I opened your ANSYS 19.2 model. I see you have a velocity to plunge this tool into the workpiece, but you don't have anything to keep the tool rotating after it makes contact.
Yes, you have an Initial Condition of Angular Velocity, but that is only present at T=0. As soon as the tool makes contact with the workpiece, contact forces will act on that tiny mass, and the rotation will stop very quickly. I must not be a very good teacher if you have not learned that lesson after all the discussion on the single point turning model.
Answers
@MAMIN219
I opened your ANSYS 19.2 model. I see you have a velocity to plunge this tool into the workpiece, but you don't have anything to keep the tool rotating after it makes contact.
Yes, you have an Initial Condition of Angular Velocity, but that is only present at T=0. As soon as the tool makes contact with the workpiece, contact forces will act on that tiny mass, and the rotation will stop very quickly. I must not be a very good teacher if you have not learned that lesson after all the discussion on the single point turning model.