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Ansys Learning Forum › Forums › Discuss Simulation › LS Dyna › dynamic relaxation for rotation › Reply To: dynamic relaxation for rotation

April 1, 2024 at 3:57 pm
Reno Genest
Ansys Employee

Hello Allen,

Is the fan blade rotating in the the dynamic relaxation phase? Dynamic relaxation us used to find the static equilibrium of a system under preload. For example, a car under gravity, bolt pretension, etc. So, if the fan blade is rotating, you won't be able to find the static equilibrium. 

The way to do this is to apply rotational centrifugal preload (without rotation) in the dynamic relaxation phase using *LOAD_BODY_RX and then apply the real rotation as an initial condition at time 0 of the explicit phase using *INITIAL_VELOCITY_GENERATION. See the following example from the Aerospace Working Group:

https://awg.ansys.com/AWG+ERIF+Test+Example+12

The Aerospace Working Group is a great resouce with example models and documents:

https://awg.ansys.com/tiki-index.php

https://awg.ansys.com/Resources

https://awg.ansys.com/MGD

 

Let me know how it goes.

 

Reno.

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