# Nonlinear material problem in ANSYS Workbench

Tags:
1. Mar 21, 2017

### Anders Johnsen

I'm currently conduction a nonlinear analysis of a partially buried, cylindrically shaped sump-system. I've decided to best simulate the stresses on the sump by modelling a shallow cylinder with gravel-properties around it and a cube with soil-properties surrounding both sump and gravel.

As I'm writing my bachelor's thesis in mechanical engineering, soil mechanics is not my field of study. As a result, I've approximated some values from an external program, CivilFEM.

However, I dont seem to be able to solve the model after adding the nonlinear Mohr-Coloumb properties to engineering data.

The data from CivilFEM is as follows;

Type: Soil

E: 8e+07 Pa

ν: 0.3

ρ: 2038.74 kg/m³

G: 3.07692e+07 Pa

α: 1e-05 1/ΔK

Act. time: 0 day

Deact. time: 36500 day

Plastic behavior: Mohr-Coulomb

Densities
ρ type: Apparent

γ dry: 20000 N/m³

γ solid: 20000 N/m³

γ apparent: 20000 N/m³

γ submerged: 10190 N/m³

γ saturated: 20000 N/m³

γ water: 9810 N/m³

ρ dry: 2038.74 kg/m³

ρ solid: 2038.74 kg/m³

ρ apparent: 2038.74 kg/m³

ρ submerged: 1038.74 kg/m³

ρ saturated: 2038.74 kg/m³

ρ water: 1000 kg/m³

Porosity: 0

Void ratio: 0

Water content ratio: 0

Mohr-Coulomb
Eff. Cohesion: 0 Pa

Φ: 30 °

Hyperbolicity: 0 Pa

Autocalculate hyperbolicity parameter: Marked

Non-associative flow rule: Unmarked

Damping
Automatic: Marked

α: 0 1/s

β: 0 s

Damping: 0 %

ω min.: 0.1 1/s

ω max.: 100 1/s

The data was input to ANSYS Workbench as shown on the picture.

Why won't the model solve? Is this due to the mix between linear properties and nonlinear properties?

Any help would be appreciated

#### Attached Files:

• ###### Sand - well graded - engineering data.png
File size:
26 KB
Views:
108
2. Mar 26, 2017

### PF_Help_Bot

Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.