Week - 3 Drop test Challenge

AIM: To perform the drop test on cellphone when it drops on the floor.

• In this challenge we have to provide material to the cellphone and the surface.
• After that we have to provide the intial velocity to it and some other properties so we can perform the sitmulation on it and get the results.

• So this is how the component looks.
• Here we can see there are three parts and we required only 2. So we will delete the part from the surface.

• The intial keyword this model content is shown below:

• Now first we will assign the section to both the parts.
• For Shell element go to the KEYWORD MANEGER>SECTION>SHELL

• For Solid element go to the KEYWORD MANEGER>SECTION>SOlID

• Now the section is assigned next is to assign the material to bothe the sections.
• For the cell phone we will use aluminium material for the cellphone case i.e. MAT024 PIECEWISE_LINEAR_PASTICITY
• Go to KEYWORD MANEGER>MAT>024 -PIECEWISE_LINEAR_PASTICITY

• For the rigid surface we will use MAT020 RIGID
• Go to KEYWORD MANEGER>MAT>020_RIGID

• Now we will assign this created Material property and section proerty to the parta as shown:
• For Cellphone KEYBORD MANEGER>PART

• For Rigid Surface

• Now we will assign the boundary conditons to the part.
• For the CelPhone we will we need cell phone to fall in veritcal directions so we will restrict all the DoF except DoF Z
• CREATE ENTITY>BOUNDARY>SPC

• And for rigid surface we will contrained all the DoF.

• Now we will assign the Surface contact to between phone and the rigid surface.
• For that we have to choose the master and slave surface.
• So for the slave we have phone and for master we have rigid surface.
• For that go to KEYWORD MANEGER>CONTACT>AUTOMATIC_SURFACE_TO_SURFACE

• Now we will assign the Velocity to the phone.
• First we will measure the distance between the rigid surface and the phone.

• Its near 20mm so the intial velocity `v=sqrt(2gh)`
• The velocity is -6mm/ms the -ve sign is because the the phone is falling in negative z direction.

• Now we will assign the output keycards for the given simulation.
• First we will assign End time for the simulation For that KEYBOARD MANEGER>CONTROL>TERMINATION

• Now we next is OUTPUT DATABASE for that go to KEYBOARD MANEGER>DATABASE>ASCII
• And GLSTAT to 0.5 GLSTAT gives you the kinetic , internal energies and other type of energies.

• Now to plot the animation go to the KEYBOARD MANEGER>DATABASE>BINARY D3PLOT
• This will show all the stress and energies in animeted format.

• Now save this file and run the simulation in LS-DYNA Program.
• Open .k file to check the program.

RESULTS:

• From the above image it can be observed that there are high stress developed when the handset impacts the rigid

GRAPH

• Here we can see the deflection in the energy occured after 3ms.

OUTCOMES:

• Able to give the different tyeps of KEYWORDS to the component.
• Learnt about the how to apply Boundry Conditions , Intial Velocity.

CONCLUSION:

• The drop test of cell phone is performed on the LS DYNA.
• And the graphs of energies has been plotted.