# Energy — Welcome to LS-DYNA Examples

A copper bar strikes a wall.

## Introduction

```*CONTROL_ENERGY
Bar Impact
LS-DYNA Manual Section: *CONTROL_ENERGY

Example: Bar Impact

Filename: control_energy.bar-impact.k

Description:
A copper bar strikes a wall.

Model:
A 1/4 symmetry bar measures 0.32 cm in radius and 3.24 cm in length and
contains 972 hexahedron element. The bar starts at 0.0227 cm/ usec and stops at
0 cm/ usec. The calculation illustrates the energy balance where
E = KE + IE + HGE.

Input:
The hour glass energy is computed at a negligible cost. (*CONTROL_ENERGY)
The initial velocity for every node is set to -0.0227 except the nodes at z = 0.

Results:
The undeformed and deformed shape of the bar are shown. The total, kinetic,
internal and hourglass energies are also shown.```

## Keywords

```*CONTROL_ENERGY
*CONTROL_HOURGLASS
*CONTROL_OUTPUT
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*DATABASE_BINARY_D3THDT
*DATABASE_GLSTAT
*DATABASE_HISTORY_NODE
*DATABASE_NODOUT
*DEFINE_BOX
*ELEMENT_SOLID
*END
*INITIAL_VELOCITY
*KEYWORD
*MAT_PLASTIC_KINEMATIC
*NODE
*PART
*SECTION_SOLID
*TITLE```

## Reduced Input

```  *KEYWORD
*TITLE
bar impact
\$
\$  LSTC Example
\$
\$
\$  Units: gm, cm, microsec, 1e+07 N, Mbar, 1e+07 N-cm
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Control Ouput
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
*CONTROL_TERMINATION
\$   endtim    endcyc     dtmin    endneg    endmas
82.10
\$
*CONTROL_ENERGY
\$     hgen      rwen    slnten     rylen
2
\$
*CONTROL_HOURGLASS
\$      ihq        qh
4
\$
*CONTROL_OUTPUT
\$    npopt    neecho    nrefup    iaccop     opifs    ipnint    ikedit
0         0         0         0                   2      1000
\$
\$
*DATABASE_BINARY_D3PLOT
\$       dt      lcdt
5.0
\$
*DATABASE_BINARY_D3THDT
\$       dt      lcdt
1.0
\$
*DATABASE_GLSTAT
\$       dt
0.5
\$
*DATABASE_NODOUT
\$  dt/cycl      lcdt
0.5
\$
*DATABASE_HISTORY_NODE
\$      id1       id2       id3       id4       id5       id6       id7       id8
1333
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Initial Conditions
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
\$\$\$\$  Nodes within box 2 are given an initial velocity in the neg z-direction.
\$\$\$\$  These are all the nodes except for those on the bottom of the bar.
\$
*INITIAL_VELOCITY
\$     nsid    nsidex     boxid
0         0         2
\$       vx        vy        vz       vxe       vye       vze
0.0       0.0   -0.0227       0.0       0.0       0.0
\$
*DEFINE_BOX
\$    boxid       xmm       xmx       ymn       ymx       zmn       zmx
2     -1.e6      1.e6     -1.e6      1.e6  0.50e-02      1.e6
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Define Parts and Materials
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
*PART
\$      pid       sid       mid     eosid      hgid    adpopt
Bar
1         1         1
\$
\$
*MAT_PLASTIC_KINEMATIC
\$      mid        ro         e        pr      sigy      etan      beta
1     8.930      1.17     0.350     0.004     0.001       1.0
\$      src       srp        fs
0.0       0.0       0.0
\$
\$
*SECTION_SOLID
\$      sid    elform
1         0
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Define Nodes and Elements
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Many nodes have boundary conditions to simulate symmetry.
\$
\$
*END```