Case4 Force-based bed length constraint (High stiffness)
Contents
The data file for this exercise is located in Rest_001/Exercices/Case4/Data. Look for ! TODO text in the datafile and follow the instructions.
The aim of this exercise is to learn to apply constraints to preserve/hinder contraction of the bed length of the top surface during restoration. The method consist in applying a force-based bed length constraint: An element group of 1D elements with a user defined stiffness and a tension yield stress is inserted and tied to the top surface. The 1D line element stiffness will hinder shortening of the bed length during flattening of the top surface to the restoration surface (note that restoration is performed by applying vertical displacement to the top surface nodes) while the yield tension strength allows control on the extension.
In this exercise the user will set up the datafile to apply force-based top surface bed length constrains to the flexural fold example. To perform this exercise:
1Modifying the Restoration_data as shown below
Force-based bed length constraint
Data File |
|
* Restoration_data ! --------------------------------- Restoration_surface "Restoration_surface" Operation_type "Translate" Bed_length_constraint_type "Bed_force1" Bed_length_constraint_data IDM=2 /"Stiffness"/ 1E12 /"Maximum Tension"/ 10
|
1The Bed_length_constraint_type keyword is set to "Bed_force1" (1D line elements are inserted to the top surface). 2The Bed_length_constraint_data must be provided. In this example the 1D element stiffness is set to 1E12 MPa and the extension yield strength is set to 10 MPa. 3Note that Restoration_data is re-defined in the next stage |
Results
The result files for the project are in directory: Rest_001\Exercises\Case4\Results. Note that the high stiffness and low maximum tension allowed to fully preserve the bed-length.
Top surface bed-length (in m) at initial (top) and restored (bottom) configurations.
|
