# # Finite Element modeling

## A phase field formulation for hydrogen assisted cracking [code included]

I hope some of you may find this work interesting, the finite element code developed (Abaqus UEL subroutine) can be downloaded from www.empaneda.com/codes

A phase field formulation for hydrogen assisted cracking

Emilio Martínez-Pañeda, Alireza Golahmar, Christian F. Niordson

Computer Methods in Applied Mechanics and Engineering, 342, pp. 742-761 (2018)

## GTN model

I have 2 questions regarding GTN model.

1) What does q1, q2, q3 signify in GTN damage model? What are their physical meanings. I know only their numerical values.
2) How to deal with the problem of GTN in Compression? It is working fine with tension but while in compression it is unable to converge.

Hello everyone,

## Local mesh refinement using Gmsh

Free Tags:

Hello All,

I am using Gmsh for creating a finite element mesh. After I create the volume mesh, Is there a way to do a local mesh refinement around a particular point (say x,y,z) and within a sphere of given radius.

Kindly help !

-Prithivi

## How to use non-dimensional form in open source codes instead of Units

Choose a channel featured in the header of iMechanica:

I am using an open source FEM platform, which requires you to convert your equation system to non-dimensional form. So, there are no units specified for the parameters in the problem. If you use compatible input units, you should expect the output in matching unit - just like one would do in a normal python or C++ code for solving physical problems. I have an elasto-plastic dynamic problem to solve, and these are the parameters for the Drucker-Prager Soil Model for soft clay.

E = 5000000;                 // Young's Modulus in N/m^2 or Pa

## How to use non-dimensional form in open source codes instead of Units

I am using an open source FEM platform, which requires you to convert your equation system to non-dimensional form. So, there are no units specified for the parameters in the problem. If you use compatible input units, you should expect the output in matching unit - just like one would do in a normal python or C++ code for solving physical problems. I have an elasto-plastic dynamic problem to solve, and these are the parameters for the Drucker-Prager Soil Model for soft clay.

E = 5000000;                 // Young's Modulus in N/m^2 or Pa

## Cant solve "too many attempts made for this increment"-issue on some models

Choose a channel featured in the header of iMechanica:

Hello at all,

I have some serious issues with some of my models in Abaqus 6.14. I need to simulate shear failure to investigate the influence of concrete strength and fracture energy on the size effect. So far, everything went good. I calculated almost 100 models without any problem with exactly the same model (only materials changed). But: For the combination of concrete strength fck=50MPa and a fracture energy of Gf=60N/m or Gf=80N/m, the calculations will stop after a short time although the .odb file shows only some minor bending cracks in the beam

## Looking for a PhD position in Bio/Biomedical Engineering

Hello

I am actively looking for a PhD in Bio/Biomedical engineering. I am interested in multidisciplinary applied research, and would prefer to work in a research group of multiple expertise.