somdattagoswami / igapack-phasefield

Second and fourth-order adaptive phase field modeling of fracture using PHT-splines in the framework of IGA.

IGAPack-PhaseField

Second and fourth-order adaptive phase field modeling of fracture using PHT-splines in the framework of IGA.

Companion paper: Adaptive fourth-order phase field analysis for brittle fracture

igapack-phasefield's Issues

Relation between the PHT nodes and controlPts.

Hello Somadatta and Cosmin,
I have been using IGAPACK for a while, and I recently came across this IGAPACK-PhaseField package. I think it has few additional functionalities to PHT geometry. One of which is calculating the PHT node coordinates (referred as controlPts in the code). While I was exploring this particular section of code, I found there is a disconnection (to my knowledge). There is a mismatch between the unique controlPts count and PHTnodes count.

Let me explain my point/confusion with an example, Consider a square (side = 1) PHT geometry with 4 active elements (level 1 elements, [2,3,4,5]), with degree p = 3 and q = 3, As we know, this PHT structure will have a 36 unique nodes. But in the controlPts array there only 24 unique coordinates. Why there is a mismatch between the two numbers? I am adding visual representation of nodes (my own interpretation based on the PHTelem struct, correct me if I am wrong) and control points generating from the code.

This particular section of code confusing me. If controlPts representing the PHTnodes, why unique nodes count is not same as unique controlPts coordinates. Could you please explain this scenario and relation between the PHTnodes and controlPts?

Thank you,
Bhagath Mamindlapelly

Reference to non-existent field 'constk'.

Hello,

I may find an error, i.e.,

CantileverBeam
Deciding the phase field model: 
 Second-order model : 1 
 Fourth-order model : 2 
 Your choice: 2
Deciding the stress degradation function: 
 1: Quadratic stress-degradation function 
 2: Cubic stress-degradation function 
 Your choice: 2
Initializing boundary conditions on the initial geometry.
Precomputing shape functions and derivatives.
History function and phase field initialization.

istep =

     1

Assembling the stiffness matrix.
Reference to non-existent field 'constk'.

Error in gStiffnessUUcubic (line 38)
                    gphi = Fract.s*((1.0-phigp).^3 -(1.0-phigp).^2) + 3*(1.0-phigp).^2
                    - 2*(1.0-phigp).^3 +Fract.constk;

Error in
CantileverBeam>@(PHTelem,sizeBasis,numberElements,dgdx,shape,Fract,Mater,volume,tdisp,geometry)gStiffnessUUcubic(PHTelem,sizeBasis,numberElements,dgdx,shape,Fract,Mater,volume,tdisp,geometry)

Error in solver_4th (line 48)
        [stiffUU,elemRef] =
        PF.StiffUU(PHTelem,sizeBasis,numberElements,dgdx,shape,Fract,Mater,volume,tdisp,geometry);

Error in CantileverBeam (line 68)
        solver_4th(Input,PF,file_name);

Best regards!

Modifying crack size, number of cracks, location, and/or orientation

Somdatta Goswami,
I am trying to use the provided phase-field models for different cases of crack size, location, and/orientation.
Two of the provided configurations are centered crack, and edge crack, but I would like to change crack size, location, and orientation.
Also, is it possible to include domains with multiple cracks/defects?

About code usage rights

Hi Somdatta Goswami,

I am Jim,a college student.We team are working on a project related to PHT splines.I have a request. May I use your code for PHT splines?If you can let me use,I will express my deep gratitude to you.

Yours sincerely,
Jim