Week - 4 - crash box simulation

Objective- To perform analysis of Crash tube impacting on a moving rigid wall and to see the results with Changing thickness of crash box.

Input Setup:

Firstly a crash tube of 1.2mm thickness iwas made to impact on rigid wall,

Material : Piecewise linear plastic material were assigned with the properties of steel with (gm,mm.ms) unit consistency and also stress strain curve data is alos given for material to show plastic deformation

Section : In first case,Section ThiCkness of 1.2mm with 2 eleform and 3 nip is given to the crash tube

And in second case the thickness is increased to 1.5mm

Rigid Wall : A moving rigid wall is created with 0.2 fric and 13.88gm/mm³ velocity

Boundary condition : Since the rigid wall is moving and going to impact on crash box, for proper deformation and avoiding the twisting the farther end of Box is constrained with spc card

Contact : A self contact is established in our model, It is done by providing automatic single surface card

Control : Following Control Cards are given :

• Contol Trmination

• Control energy

Database: For desired results following output cards are given :

• Ascii Option : Glastat, Nodout, rcforc, rwforc, sleout

Result :

Plot of energies :

• Kinetic enegy is decreasing with time and internal energy behaving opposite to Kinetic energy is increasing with time

• Hourglass and Sliding energy remains zero

Comparision of stress_strain values :

For Thickness 1,2 mm :

For Thickness 1.5 mm :

Comparision of acceleration :

For Thickness 1.2 mm :

For thickness 1.2 mm the resultant acceleration is found to be 1.2 mm/ms²

For Thickness 1.5 mm :

For thickness 1.5 mm the resultant acceleration is found to be 1.48 mm/ms²