Week - 5 - Modelling Spotwelds

Introduction

This project is about modelling spotwelds using beams and solid element between two shell sections. Comparison of beam and element are made by comparing shear force and axial force.

Given File

The file consists of two shell sections, they are named as top section and bottom section. It is meshed and consists 10011 elements and 10296 nodes

Model –

Procedure-

• A rigid wall is not given in K file for crashing, a rigid wall is created by Create entity RIGIDWALL_PLANAR from offset of 10mm from Crash box
• 3 beam are formed by using mesh>element generation

• Two shell sections are made into set and beams are made into another set.

  They are assigned CONTACT_TIED_SHELL_EDGE_SURFACE(beams as slave and solid as master)
• Then CONTACT_AUTOMATIC_SINGLE_SURFACE KEY CARD is assigned. Only slave is given by beams because Crash causes shell section will be deformed to itself
• • Velocity is given as 13.88mm/ms (50kmph) for crash box by INITIAL_VELOCITY in x direction
  • Beam section is defined with element formulation of 6
  • Material properties are given as steel properties for spotwelds (MAT_SPOTWELD) and elastic(MAT_ELASTIC)
  • Database options are given (GLSTAT,SWFORCE,ELOUT,D3PLOT) at timestep of 1 millisecond
  • CONTROL_TERMINATION is given as 2 sec

  For solid spotweld

• • Section is defined as solid with element formulation 1
  • Solid parts are created by using element editing at three areas
  • CONTACT_SPOTWELD is given solid as slave and shell are master
  • -Then CONTACT_AUTOMATIC_SINGLE_SURFACE KEY CARD is assigned. Only slave is given by beams because Crash causes shell section will be deformed to itself
  • Material properties are given as steel properties for spotwelds (MAT_SPOTWELD) and elastic(MAT_ELASTIC)
  • Material and section properties are assigned to part
  • Database options are given (GLSTAT,SWFORCE,ELOUT,D3PLOT) at timestep of 1 millisecond
  • CONTROL_TERMINATION is given as 2 sec

  Finally it is solved in solver

• RESULTS

  THE GIVEN INPUT IS SOLVED

• Comparison of axial and shear forces

  -SWFORCE FOR BEAMS

• -SWFORCE FOR SOLIDS

• shear force is more in solids and axial force is more in beam spotwelds

• GLSTAT COMPARISON

• GLSTAT FOR BEAMS SPOTWELDS

• GLSTAT FOR SOLID SPOTWELDS

  Glstat is comparatively same for both solid and beams spotwelds

  ANIMATION

• BEAMS SPOTWELD ANIMATION (V-M)

  SOLID SPOTWELD ANIMATION (V-M)

  This is evident in above picturesthat V-M stress is more in solid compared to beams

  ACCLERATION COMAPRISION-

  BEAMS

• SOLIDS-Part data

  Conclusion

• given model is analysed(solved) and compared between solids and Beams spotweld

  The end--------------