Drop_Test of ball

I am trying to perform a simple drop test of ball on ground. (Both being Flexible and of same material (Steel)).
The initial gap between ball and ground is 5mm. but when i see the animation file, the ball bounces after ~4.72mm.
can some one please help me.

Unable to find an attachment - read this blog

Find more posts tagged with

English

Radioss

Accepted answers

All comments

hari0811

Starter and Engine Files.

Unable to find an attachment - read this blog

Altair Forum User

Change the material type to M2_PLAS JOHNS ZERIL (elasto plastic material) and run the analysis. Provide appropriate material properties so that a realistic behavior of the simulation can be achieved.

hari0811

ok I will launch using elasto plastic material and update you.
But i am wondering how will that effect the physics of my problem. The ball should touch the other part and it should bounce back.

Altair Forum User

Material properties plays a vital role in simulation.

The input parameters will define the weight of the component. So input a reasonable value of E and rho.

Please update after the run.

<?xml version="1.0" encoding="UTF-8"?>

hari0811

Hello George

I have tried using M2_PLAS JOHNS ZERIL and i have same problem.
can you send me the your model from the picture

Thankyou

Altair Forum User

Can you upload the model now

hari0811

Unable to find an attachment - read this blog

Altair Forum User

Model the ground with elasto plastic material and run the analysis. Update it with the Plas Johns Zeril material.

hari0811

Hi George

I have solved the problem, The problem was in GAPmin which was taking a default value because of which it was not coming into contact.

Now i have a new problem which is drop in energy when the ball contacts with ground. ( My ground and Ball are flexible)

Do you know why such thing happens ?

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Please upload the deck file (0000.rad) and T01 file.

hari0811

PFA the files.

Unable to find an attachment - read this blog

Altair Forum User

Hi Hari,

Can you check if there is any change in the KE

Usually if the collision is a plastic collision there will be considerable KE loss due to plastic deformation.

Also, total energy doesn't account for hourglass energy. So you may also have to check hour glass and contact energies.

hari0811

Hello Prakash

I am using Elastic model hence plastic deformation is not the problem,
I just checked the contact energy, it has some energy which is the drop in energy.

Total Energy = sum of internal energy + kinetic energy + external force work - Contact energy - hourglass energy - internal spring energy ?

Is my understanding is correct ?

<?xml version="1.0" encoding="UTF-8"?>