## General Mechanical

#### Self-Loosening effect

• Andi Ko
Subscriber

I want to simulate the self-loosening effect with this geometry design. currently, I'm using transient analysis with 3 step method, where in the first step I turned off time integration as I applied the initial load. But it is still not working. does anyone here have any idea or maybe have the same problem as me?

• peteroznewman
Subscriber

More details are needed to understand your model. Is the spindle connected to ground? Spell out what happens in each step. Step 1, apply Moment with Time Integration Off. Step 2 ...? Where are you applying the displacement on the moving plate?  How much displacement are you applying?  Is this a Displacement value or a Displacement function that causes a sinusoidal motion over time?  Details!

• Andi Ko
Subscriber

sorry for the unclear question, here I attached my progress. I used rotation load for the moment (applied at the top surface of the locknut) at step 1 with time integration off. in step 2, I did not apply anything here. then, turn on time integration and change the time step to 0.001s

step 3-12, I applied displacement load with 3.5mm and -3.5mm sequences only in x direction so di moving plate will hit the ring.

bottom of the fixed plate and bottom of spindle are fixed support

• peteroznewman
Subscriber

Please elaborate on what "not working" means. Show the error message.

• Andi Ko
Subscriber

• Andi Ko
Subscriber

the error start when the solver change from step 1 to step 2 where the time integration change

• Andi Ko
Subscriber

my analysis setting

• peteroznewman
Subscriber

I assume these parts are steel.  Have you tried pushing on steel and getting it to move 0.5 mm. It takes an enormous force. Why did you choose 0.5 mm?  Try running a Static Structural model and see if you can statically deform the parts with a 0.5 mm displacement (or just make a 2 step solution in Transient Structural with time integration off in step 2). Maybe an interference of 0.05 mm or smaller would be more appropriate. Please reply with the reaction force from these two displacements.

Why did you choose a vibration frequency of 20 Hz?  What is the first natural frequency of this structure?  You should run a Modal analysis and see what that is.