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Swinging square — free vibration

A unit square, roller supports, quad4 mesh. The stored FLagSHyP dynamics run is a free vibration: play the time history and watch kinetic and strain energy exchange.

Swinging square

FLagSHyP · DYN_swinging_square_fine · 2D dynamic free vibration

Unit square · quad4 8×8 · roller BCs · t = 0 → 5

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Ready
|U|
00
Boundary conditions
icode 1 · UX = 0
icode 2 · UY = 0
icode 3 · pin UX=UY=0
Initial velocity arrows
Increment
Center |U|
Max |U|
Nodes
Q4 elems
Frames
Energy history

Problem

  • Unit square $[0,1]^2$, hyperelastic continuum (matyp 1)
  • Structured quad4 mesh: 81 nodes · 64 elements
  • Roller BCs: left/top $U_X=0$, bottom/right $U_Y=0$; opposite corners pinned
  • Initial velocity field → free “swinging” vibration to $t_{\max}=5$

Viewer notes

  • Displacements are small ($\sim 10^{-3}$); default scale is $400\times$
  • Frames from restart files every 10 increments ($\Delta t = 0.0125$)
  • Energy plot from final restart total / kinetic series