Small restart example: Bolt pre-tensioning followed by prescribed loading

In the first stage, bolt pre-tensioning is applied to a bolted flange joint, see Figure 53. Non-linear material properties are used both in the pipes and the bolts. The example keyword file is pretens001.key. This keyword file also includes the definitions of the applied loadings.

Example Files: pretens001
NOTE! All examples are included in the Complete Guideline

In the following analysis (small_restart.key), loading is applied in the Y-direction, by redefinition of the load curves using the keyword *CHANGE_CURVE_DEFINITION. The result is shown in Figure 54. For this example, R11.2, R13.1 or R14.1 of LS-DYNA is recommended.

Main Input

*KEYWORD
$===============================================================================
$ Control and output cards
$===============================================================================
*INCLUDE
../INCLUDE_FILES/control_cards_nonlin.key
*INCLUDE
../INCLUDE_FILES/database_cards_static.key
*CONTROL_IMPLICIT_GENERAL
$   IMFLAG       DT0    IMFORM      NSBS       IGS     CNSTN      FORM
         1      0.10         2         0         1         0         0
*CONTROL_TERMINATION
$   ENDTIM    ENDCYC     DTMIN    ENDENG    ENDMAS
        1.
*CONTROL_IMPLICIT_DYNAMICS
$    IMASS     GAMMA      BETA    TDYBIR    TDYDTH    TDYBUR     IRATE
         1       0.6      0.38                 0.6       0.8         2
*DEFINE_CURVE_TITLE
Time stepping curve
       700
                  0.                0.10
                  1.                 0.2
                  2.                 0.2
$===============================================================================
$ Pipes geo
$===============================================================================
*INCLUDE
flange005.key
$===============================================================================
$ Contacts
$===============================================================================
*SET_PART_LIST_TITLE
FLANGES
      1100
  70770912  70770914
*SET_PART_ADD_TITLE
All for contact
      1119
       100      1100
*CONTACT_AUTOMATIC_SINGLE_SURFACE_MORTAR_ID
1001      Bolts_and_flanges
      1119                   2
      0.15                                                                      
        5.


         5
$===============================================================================
$ Loading and boundary conditions
$===============================================================================
*BOUNDARY_SPC_SET
       112                   1         1         1
*DEFINE_CURVE_TITLE
Bolt pre-tension 600 MPa
      1002
0.,0.
1.,.6
*INITIAL_STRESS_SECTION
$    issid      csid      lcid      psid
         1         1      1002       100
         2         2      1002       100
         3         3      1002       100
         4         4      1002       100
         5         5      1002       100
$===============================================================================
*DEFINE_CURVE_TITLE
X-loading
      1001
0.,0.
1.,0.
2.,10.
*DEFINE_CURVE_TITLE
Y-loading
      1021
0.,0.
1.,0.
2.,0.
*DEFINE_CURVE_TITLE
Z-loading
      1031
0.,0.
1.,0.
2.,0.
*LOAD_NODE_SET
$     nsid       dof      lcid        sf
      1001         1      1001       1.0
      1001         2      1021       1.0
      1001         3      1031       1.0
$===============================================================================
$ Additional output - elout
$===============================================================================
*DATABASE_HISTORY_SOLID
     18554
*DATABASE_HISTORY_NODE_SET
      1001
*SET_PART_LIST_GENERATE
       666
         1  99999999
*INTERFACE_SPRINGBACK_LSDYNA
       666
$===============================================================================
$ Simulation title
$===============================================================================
*TITLE
180124-bolts pre-tensioning for restart analyses, single surface
*END