giacuni
Civil/Environmental
- Oct 14, 2016
- 11
Hello everyone,
I am trying to simulate the accumulated deformation after several cycles (passage of a train) in a railway track.
My idea is that, after each cycle, the vertical permanent deformation is calculated using an empirical equation. Then, at the end of the cycle, the vertical permanent deformation computed is integrated into the model, so that at the start of the following iteration, the railway track state is updated.
The model is a 3D model that comprises rails, railpads, sleepers, ballast and subgrade. As material property of the ballast and subgrade (the only layers for which I will determine the permanent strain induced by the passage of trains), I will use a non-linear elastic constitutive equation.
The problem now is how to specify in ABAQUS after each iteration the vertical deformation of each element? For what I know there are two methods:
1. Using predefined fields: BUT it requires the use of plasticity to use the "initial plastic strain" command;
2. Applying BCs: BUT applying an initial vertical displacement I will induce within elements an unwanted stress-state.
I want to apply vertical deformation just to change the geometry of the problem, not to induce stress state. I want that after I have applied the initial deformation the stress will be however equal to zero. Do you know if there is a method to do that?
Thank you in advance for answering
Best
Giacomo
I am trying to simulate the accumulated deformation after several cycles (passage of a train) in a railway track.
My idea is that, after each cycle, the vertical permanent deformation is calculated using an empirical equation. Then, at the end of the cycle, the vertical permanent deformation computed is integrated into the model, so that at the start of the following iteration, the railway track state is updated.
The model is a 3D model that comprises rails, railpads, sleepers, ballast and subgrade. As material property of the ballast and subgrade (the only layers for which I will determine the permanent strain induced by the passage of trains), I will use a non-linear elastic constitutive equation.
The problem now is how to specify in ABAQUS after each iteration the vertical deformation of each element? For what I know there are two methods:
1. Using predefined fields: BUT it requires the use of plasticity to use the "initial plastic strain" command;
2. Applying BCs: BUT applying an initial vertical displacement I will induce within elements an unwanted stress-state.
I want to apply vertical deformation just to change the geometry of the problem, not to induce stress state. I want that after I have applied the initial deformation the stress will be however equal to zero. Do you know if there is a method to do that?
Thank you in advance for answering
Best
Giacomo