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Two rigid shell elements are joined together using a revolute joint. A stop angle is defined so that the rotating plate can only rotate 30 degrees relative to the other plate.

Introduction

*CONSTRAINED_JOINT_REVOLUTE
Hinged Shell with Stop Angle (Revolute Joint)
LS-DYNA Manual Section: *CONSTRAINED_JOINT_REVOLUTE

Additional Sections:
*CONSTRAINED_JOINT_STIFFNESS
*CONTROL_TIMESTEP

Example: Hinged Shell with Stop Angle (Revolute Joint)

Filename: constrained.joint_revolute.k

Description:
Two rigid shell elements are joined together using a revolute joint.
A stop angle is defined so that the rotating plate can only rotate 30 degrees
relative to the other plate.

Model:
A pair of concentrated loads are applied to the end nodes of a hinge-jointed
shell system using * LOAD_NODE_POINT. One of the rigid plates is fixed by
using the capability within the *MAT_R IGID keyword. The rotating plate has
a stop angle of 30 degrees relative to the fixed plate defined using the
*CONSTRAINED_JOINT_STIFFNESS_GENERALIZED keyword.

Because all components in the model are rigid, the time step needs to be
controlled by limiting the maximum time step to 4.15E-06 s. (In deformable
structures, the minimum time step is usually the one of concern.)

Results:
The rotating plate at several states are shown imposed on each other.
The maximum rotated angle is closer to 38 degrees rather than the specified
30 degrees. This is because the joint stiffness actual defines the angle at
which the resistance force is to begin. The forces associated with stopping
the rotating plate can be determined by examining the jntforc ascii file.

Keywords

*CONSTRAINED_JOINT_REVOLUTE
*CONSTRAINED_JOINT_STIFFNESS_GENERALIZED
*CONTROL_TERMINATION
*CONTROL_TIMESTEP
*DATABASE_BINARY_D3PLOT
*DATABASE_GLSTAT
*DATABASE_HISTORY_NODE
*DATABASE_JNTFORC
*DATABASE_NODOUT
*DATABASE_RBDOUT
*DEFINE_COORDINATE_NODES
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*KEYWORD
*LOAD_NODE_POINT
*MAT_RIGID
*NODE
*PART
*SECTION_SHELL
*TITLE

Reduced Input

  *KEYWORD
  *TITLE
  hinged shell w/ stop angle
  $
  $  LSTC Example
  $
  $  Last Modified: October 16, 1997
  $
  $ - This problem has a pair of concentrated loads applied to
  $   the end nodes of a hinge-jointed shell system.  
  $
  $ - 30 degree stop angle (must add joint stiffness, local coord system)
  $
  $ - control timestep with maximum 4.15E-06
  $
  $  Units: lbf-s2/in, in, s, lbf, psi, lbf-in
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Control Ouput
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONTROL_TERMINATION
  $   endtim    endcyc     dtmin    endeng    endmas
   2.000E-02
  $
  *CONTROL_TIMESTEP
  $   dtinit      scft      isdo    tslimt      dtms      lctm     erode     ms1st
                                                             5
  $
  *DEFINE_CURVE
  $     lcid      sidr      scla      sclo      offa      offo
           5
  $           abscissa            ordinate
                   0.0            4.15E-06 
                   1.0            4.15E-06 
  $
  $
  *DATABASE_BINARY_D3PLOT
  $       dt      lcdt
   5.000E-04
  $
  *DATABASE_GLSTAT
  $       dt
      0.0001
  $
  *DATABASE_JNTFORC
  $       dt
   1.000E-04
  $
  *DATABASE_NODOUT
  $       dt
      0.0001
  $
  *DATABASE_HISTORY_NODE
  $     nid1      nid2
           3         4
  $
  *DATABASE_RBDOUT
  $       dt
      0.0001
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Revolute Joint
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONSTRAINED_JOINT_REVOLUTE
  $
  $  Create a revolute joint between two rigid bodies.  The rigid bodies must
  $  share a common edge to define the joint along.  This edge, however, must
  $  not have the nodes merged together.  Rigid bodies A and B will rotate 
  $  relative to each other along the axis defined by the common edge.
  $
  $  Nodes 1 and 2 are on rigid body A and coincide with nodes 9 and 10
  $  on rigid body B, respectively.  (This defines the axis of rotation.)
  $
  $  The relative penalty stiffness on the revolute joint is to be 1.0,
  $  the joint is well lubricated, thus no damping at the joint is supplied.
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $       n1        n2        n3        n4        n5        n6       rps      damp
           1         9         2        10                           1.0
  $
  $
  $
  $$$$$$$$$$$$  Define a joint stiffness for the revolute joint described above. 
  $
  $  Attributes of the joint stiffness:
  $    - Used for defining a stop angle of 30 degrees rotation
  $        (i.e., the joint allows a positive rotation of 30 degrees and
  $           then imparts an elastic stiffness to prevent futher rotation)
  $    - Define between rigid body A (part 1) and rigid body B (part 2)
  $    - Define a local coordinate system along the revolute axis
  $        on rigid body A - nodes 1, 2 and 3 (cid = 5).  This is used to
  $        define the revolute angles phi (PH), theta (T), and psi (PS).
  $    - The elastic stiffness per unit radian for the stop angles
  $        are 100, 10, 10 for PH, T, and PS, respectively.
  $    - Values not specified are not used during the simulation.
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONSTRAINED_JOINT_STIFFNESS_GENERALIZED
  $     jsid      pidA      pidB      cidA      cidB
           1         1         2         5         5
  $
  $   lcidPH     lcidT    lcidPS   dlcidPH    dlcidT   dlcidPS
  
  $
  $     esPH      fmPS       esT       fmT      esPS      fmPS
       100.0                10.0                10.0
  $
  $    nsaPH     psaPH      nsaT      psaT     nsaPS     psaPS
                  30.0
  $
  $
  *DEFINE_COORDINATE_NODES
  $      cid        n1        n2        n3
           5         1         2         3
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Loading
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *LOAD_NODE_POINT
  $      nid       dof      lcid        sf       cid        m1        m2        m3
           3         3         1-1.000E+00
           4         3         1-1.000E+00
  $
  *DEFINE_CURVE
  $     lcid      sidr      scla      sclo      offa      offo
           1
  $           abscissa            ordinate
        0.00000000E+00      1.00000000E+00
        1.00000000E+00      1.00000000E+00
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Parts and Materials
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *PART
  $      pid       sid       mid     eosid      hgid      grav    adpopt
  rotating
           1         1         1         0
  fixed
           2         1         2         0
  $
  $
  $$$$  Materials
  $
  *MAT_RIGID
  $
  $      mid        ro         e        pr         n    couple         m     alias
           1 7.000E-04 3.000E+07 3.000E-01          
  $
  $      cmo      con1      con2
  
  $
  $   lco/a1        a2        a3        v1        v2        v3
  
  $
  $
  *MAT_RIGID
  $
  $      mid        ro         e        pr         n    couple         m     alias
           2 7.000E-04 3.000E+07 3.000E-01          
  $
  $      cmo      con1      con2
         1.0         7         7
  $
  $   lco/a1        a2        a3        v1        v2        v3
  
  $
  $
  $$$$  Sections
  $
  *SECTION_SHELL
  $      sid    elform      shrf       nip     propt   qr/irid     icomp
           1         2                 3.0
  $       t1        t2        t3        t4      nloc
         0.1       0.1       0.1       0.1
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Nodes and Elements
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  *END

Figures

image01.gif

image02.gif

Animated Result

Result

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