/PRELOAD

Block Format Keyword Defines a preloading stress applied to the section of a 3D bolt.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/PRELOAD/preload_ID/unit_ID
preload_title
sect_ID sens_ID Itype   Preload Tstart Tstop

Definitions

Field Contents SI Unit Example
preload_ID Bolt preloading block identifier

(Integer, maximum 10 digits)

  
unit_ID Optional unit identifier

(Integer, maximum 10 digits)

  
preload_title Bolt preloading block title

(Character, maximum 100 characters)

  
sect_ID Section identifier to which the preloading is applied

(Integer)

  
sens_ID Sensor identifier
≠ 0
Preloading stress is applied after sensor activation. Tstart and Tstop are shifted in time accordingly

(Integer)

  
Itype Preloading type
= 1 (Default)
Preload is a force
= 2
Preload is a stress

(Integer)

  
Preload Preloading value

Default = 0.0 (Real)

 [ N ] or [ Pa ]
Tstart Start time for bolt preloading

(Real)

 [ s ]
Tstop Stop time for bolt preloading

Default = 1030 (Real)

 [ s ]

Comments

  1. The preloading tension stress is applied to a bolt modeled with solid elements.
  2. The sect_ID input is mandatory. It refers to a transversal cross-section of the bolt. Its normal vector (local z direction of the section coordinate system) points out the pre-stress direction in the bolt.
  3. If Itype = 1, the uniform preloading stress is calculated using the preload defined force divided by cross section initial area defined by the sect_ID.
  4. If Itype = 2, the preloading stress applied to the elements of the section is the value provided by the user.
  5. /TH/SECTION should be defined to output the preload force in the model.
  6. The resulting preloading force in the bolt can be less than the user’s entered value. This is due to the initial deformation of the section elements and initial gaps between the parts being bolted. It is recommended to enter a higher value than the targeted one or to reduce the initial gap separating the parts.