Variation in Simulation results and experimental results
Dear Gopal,
Please find the attached hm file.
Thanks
RAM
Hi,
I was going through the model and following issues are noticed.
1) Penetration and intersection needs to be cleared.
2) Quality of mesh needs to be reviewed . Warpage <15, skew<40, jacobian>0.6, min. length now is 2.15 can be increased for better time step etc.
Is the material property entered is test data ?
Also I think you have not taken the output for the reaction force Vs displacement. This can be done by making the RBODY for both upper and lower actuators and then requesting output blocks for it , so that you can compare the same with experimental data.
Also model washers at the mounting locations as maintained in physical testing.
Have you also tried with imposed displacement/velocity as load instead of force?
Dear Gopal,
I had one doubt, for this type of analysis what type of material properties should be used?
Data available for steel tube (CR)
Yield stress ,Min =180Mpa
Max= 240 Mpa
Tensile stress ,Min =310Mpa
Max= 370Mpa
Which value should be used Min or Max??
Thanks
RAM
Hi,
This is a range of values and generally for co-relation we need actual material properties (by test data) and it is more important here as it is case of plasticity. If not available, you need to alter the values in the above range and see whether it is co-relating with testing or not.
Dear Gopal,
I came to know that physical testing of seats is done for 55 sec.
Ramp time achieve the max load is 25 sec
Once the max load is achieved the load is maintained constant for 30 sec.
How it can be simulated with less solving time???
Thanks
RAM
Hi,
I think this can be done with non-linear quasi-static analysis type in optistruct where the time is not a factor and solver will maintain the load ramping so that equilibrium condition is defined at every interval.
Dear Gopal,
In this journal they co-related the results for H1H2 test

Hi Ram,
Even though this kind of analysis seems to be a quasi static problem it involves strong contacts and chances of local buckling. And I think It's quite difficult to converge in implicit.
But give a try.
Meanwhile please see a research paper in this link where a similar analysis was done: https://edupediapublications.org/journals/index.php/IJR/article/download/3096/2973
Hi,
Can you share the .hm or .rad files for this .(version 13)?