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[nikhilkhaire16]

Hello Team,

Currently, I am exploring the selective mass scaling technique for mass scaling. I performed some simulations with convetional and selective mass scaling (CMS and SMS). I found that SMS performing much better than CMS in terms of accuracy and simulation time. With SMS almost 50% more time saving was achieved than CMS. Since, I wanted to understand  why SMS is saving more simulation time compared to CMS?. I cheked the log file, t time step and number of iteration were same. Also, the mass added and the elements on which it gets added are same. 

Please let me know if anyone have any suggestions on it.
Thank you.

[Nanda Veralla]

Hello Nikhil,
Your observations are correct, despite selective mass scaling (SMS) being more computationally intensive due to its requirement for solving a sparse system of equations at each time step, it often results in less overall simulation time due to its ability to maintain accuracy with fewer iterations. SMS uses a preconditioned conjugate gradient method (PCG) for solving the equations. The iterative nature of SMS means that while it may require more CPU resources per time step, it can converge faster overall for certain problems, especially in complex simulations where accuracy is critical

This is likely why you observed a 50% reduction in simulation time when using SMS compared to CMS. Hope this helps.

Regards,

Nanda.

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[nikhilkhaire16]

Thank You team for the reply.

I am still confused. IF SMS is slower per time step, but can achieve accurate results with fewer time steps, leading to faster overall convergence in complex simulations....Why the number of iterations and Time steps is same for SMS and CMS and still SMS saving 50% time...
how to check it any notable things in logfile or any ls dyna file where I can find the solid reason in the saving simulation time?

[Nanda Veralla]

Hello Nikhil,

We will address your question in a while, I was on vacation and back in the office today.

Thanks,

Nanda