Week - 3 Drop test Challenge

Aim

The Aim of this challenge is to perform the drop test of a cell phone from the giving mesh file of a phone and the ground. In this we have assign the material, element formulatioan, Boundary conditions, Initial Velocity, contact, Control termination and update the database foe d3plot from the meshing file for the results.

Explination

• Assigning material

The given meshing file has 3 parts. One is cell phone , 2&3 are solid and shell surface mimicing ground.

For the simplicity , I assume cell phone is made up of Aluminum and is a elastic material. So I used the material code MAT_01. And the values are taken from the online and updated as below

here units are taken as mm, kg and ms. mm due to the meshing size as it is in mm. and ms due to the low crash time. and the values are converted and updated according to it

And for rigid wall , I have used the rigid body material code i.e, MAT_020. And the values are taken from the Honda Accorde file for NHTSA and as below

• Assigning Section

For the Cell phone section Section solid is used and given the element formulation of 2. It is shown as below

And for the ground part , two section id are created. One is given Section_Solid and the second one is given solid shell. And both are given the element formulation 2

• Assign both material and section to the part

After creating material and section , it has to add to the part.

• Adding Boundary Condition to the Ground mesh

As the ground part is fixed it has to constrained form all the sides. So in order to that we have to create an entity from Boundary_spc. then create NSID contains whole Ground selected. After that applying constraints on X, Y, Z ,RX, RY & RZ.

• Adding Initial_Velocity to the Cell Phone

As the cell phone is dropping on the ground, it has to be given some initial velocity. And in this i assume is dropping at the 10mm/ms as the distance between phone and ground is around 10mm. And it going around negative Z direction.

• Adding Contact between the Phone and ground

In this there is a surface contact between the Phone and Ground. So the node set is created for both phone surface and ground surface.

1st node set contain the elements lower tip of the phone

2nd set is the red surface of the ground where the phone is in contact

And the slave is assigned to phone and the master is assigned to the ground

• Control termination

The time of analysis around 10ms has been updated in it. as the initial velocity is given 10mm/ms and the distance it has to travel is 40mm fro and then rebound. So by considering all these the run time is assume as 10ms

• Control energy

As there is a contact between the phone and the ground. the sliding energy has to be considerd. So SLNTEN has to be updated as 2.

• Database

the time step has to be taken as 0.1ms and updated d3 plot. and update the ASCII options if required. Here as it is a contact we can checkout RCFORC

• Model Check

And check the model for deviations.

Finally save the file and run it in LS Run. then open another LS pre post for Binary results. It runs as follows

and the final output with von misses fringe compenent is

Conclusion

In this we performed a drop test of a cell phone on thre ground from the mesh file contains nodes and elemnts. all the necessary key words are defined with approximations and the whole sequence is mentioned as above. and finally we run the file and got the output results.