Week - 3 Drop test Challenge
Aim : perform drop test simulation for given keyword file using intial velocity.
Procedure :
open key file to the LS PrePost
File >> Open >> Ls Dyna Keyword file >> select the file and open
after reviewing model we obsorbed that we have 3 component
1 shell for floor
2. solid for cell phone
3. solid for floor
now we we delete the solif floor and performed simulation on shell floor and solid cell.
Now create section for solid and shell for cell and floor respectively
Model and part >> keyword manager >> All >> Section >> shell
Title : floor_Rigid
SecID : 1
T1/T2/T3/T4 : 1
ELFORM: 2 (Belytschko-Tsay (default),
PropT: 1 ( average resultants and fiber lengths (default),)
SETYP : 1 ( Lagrangian,)
now accept >> done
for cell create solid section
Model and part >> keyword manager >> All >> Section >> Solid
Title : Cell_Section_ALUMINIUM
SECID : 2
ELFORM : 1 (constant stress solid element (default),)
Now accept >> done
now we will create material card for cell and floor
for cell phone we will use Kg-mm-ms unit consitency
mass density of aluminium : 2.8E-6 Kg/mm^3
Young's Modulus of aluminium : 70 GPa
Poission Ration : 0.33
Model and part >> keyword manager >> All >>MAT >> 001-ELASTIC
Accept >> done
now for rigid floor we will use steel as material with higher young's modulus which is 500 GPa.
Mass density of steel = 7.83e-06 Kg/mm^3
Young's Modulus of steel ( this case) : 500 GPa
Poission's Ratio : 0.3
CMO (Center of mass constraint option) : 1 (constraints applied in global directions)
CON1 : 7 (constrained x, y, and z displacements.)
CON2 : 7 (constrained x, y, and z rotations.)
Model and part >> keyword manager >> All >>MAT >> 020 -Rigid
Accept >> done
as we had define section and material now we will assign section id and material property to the parts
Model and part >> keyword manager >> Model >>Part >> Part
click on draw and expand the tab
Title : Floor_rigid_part
PID : 1
SECID : 1
MID : 2
Now select the cell Part
Title : CELL_PART_AL
PID : 3
SECID : 2
MID : 1
now we will assign velocity to cell
Model and part >> Create entity > Intial >> Velocity >> select cell model by PART
now assign velocity to negative Z direction with magnitude of -10 mm/ms
click on apply >> done
now define the contact between cell and floor.
Model and part >> keyword manager >> all > contact >> AUTOMATIC-SURFACE-TO-SURFACE
Title : CONTACT_CELL_FLOOR_STS
CID :1
SSTYP : 3 (part ID)
MSTYP :3 ( Part ID)
SSID : 3 (cell)
MSID : 1 (Floor)
accept >> done
now measure the distance
as cell is at distance of 33 mm so we can conclude that cell will reach the floor in 4th milisecond of simulation , thus we will terminate the simulation in 5 ms
Modeland part >> keyword manager >> all >> control >> Termination
SET ENDTIM as 5 ms
Accept >> done
now define hourglass control card
Model and part>> keyword manager >> all >> control >> Hourglass
ISH (Default hourglass viscosity type:) : 1 standard LS-DYNA,
Hourglass coefficient, QH (default = 0.1)
accept >> done
Now set the database card from simulation
Model & part >> keyword manager >> all >> databse >> BINARY_D3PLOT
Set DT as 0.5
Accept >> done
now define RCFORC card
model and part >> keywrd manager >> all >> database >> ASCII_OPTION >> RCFORC >> set DT as 0.1
the below are the list which we had use in this simulation
now save the model
for sun the simulation fo to file >> RUN LS DYNA
Select the file
click on run symbol
as our run is normal ternimated
now open D3PLOT file in new LS PREPOST TAB to view the model
STress ON Z AXIS
Von mises stress :
Kinetic energy : Cell
Internal Energy : cell
Total energy : cell
Conclusion: we had sucessfully performed drop test of cell phone and simulation results are shared.