PARADISCYL:Cylinder-Algorithm

Cylinder Code Algorithm

ill Ryu and Wei Cai

This wiki page describes the ParaDiS Cylinder code v.2.5.1. This version of the Cylinder code is created by a translation from the ParaDiS ThinFilm code v.2.5.1, with subsequent modifications. In this wiki page, we only describe the difference between the Cylinder code and the translated ThinFilm code.

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List of Files

The following is a list of all files modified manually after the translation.

1. AllSegmentStress.c

Changes are made in this file to construct the test cases.

A new function AllSegmentStress_no_cell_test1() is added, which computes the stress field of a
infinite straight dislocation (analytic expression) for Test Case 1 only.  This function is activated
when CYL_TEST1 is defined (in the makefile).

Function AllSegmentStress_no_cell() is modified to account for periodic images in Z direction.
A local variable NimgPBC is hard coded.  For each dislocation segment, NimgPBC number of its images
are included in the stress calculation.  We should move this to Param.h. 

Macros (#ifdef 's) are added to make the Cylinder code use FULL_N2_FORCES when _CYL_TEST23 is defined. 
The same changes also affect these files: Initialize.c, LocalSegForce.c,  NodeForce.c.

2. Cylinder_Remesh.c

In function Cylinder_Remesh(), added new rules to remove surface debris (to increase time step).
Surface debris are defined as dislocation line consisting of two or three segments with two
(end) surface nodes. 

See [Cylinder-Remove_surface_debris].

A new function ProjectSurfaceNodes() is defined to project nodes flagged by CYLINDER_SURFACE_NODE
back to the cylinder surface when it drifts inside the cylinder.  Note that surface nodes moving 
out of the cylinder are already handled by Cylinder_Remesh.

See [Cylinder-Project_surface_node].

3. MobilityLaw_BCC_glide.c - Modify mobility for the surface node(keeping them on the surface/ slip plane) - Surface Cross Slip - Surface node mobility correction - etc

4. Collision.c

Added lines to turn off collision if param->collisionoMethod is specified as a negative number 
(in the input file).

5. cylinder.c

In function CYL_stress_boundary(), a minus sign is added in computing the surface traction from 
the infinite stress:
         tr[j+i*nq] = -cylstress[0][0];
         tq[j+i*nq] = -cylstress[0][1];
         tz[j+i*nq] = -cylstress[2][0];

6. gridstress.c

Added lines to scale the image stress calculation when the cylinder radius is not 1.  This removes
the (old) constraint that the cylinder radius has to be one.

See [PARADISCYL:Scale-Rule].

6. Remesh.c, Cylinder_Remesh.c

Make substitutions: SURFACE_NODE -> CYLINDER_SURFACE_NODE.  
This is supposed to be handled by translation.

7. SplitSurfaceNodes.c PredictiveCollision.c ProximityCollision.c

- For the surface node split (not implemented yet)