Simulation penetration hollow cylinder into the soil

[Geotech2011]

I am modelling the penetration of a hollow cylinder into the saturated soil by axisymmetric model using Abaqus 6.10 . I defined saturated soil and cylinder body with CAX8RP and CAX8R elements, respectively. I have defined 3 parts (1- the soil that form internal soil after peneteration, 2-The soil which will be left outside the cylinder after penetration, 3-hollow cylinder body ). Initially, I put the tip of the cylinder on the common line of two parts of soil. I know that I should define interaction between soil/cylinder and Soil/Soil using contact pairs. For this purpose, I choose those surfaces of soil and cylinder that have a contact together as a slave and master surfaces, respectively. However, The cylinder has not been penetrated into the soil by sliding movement. I was wondering if any body could help me regarding my problem. Many Thanks.

 

[lanavi017]

How many steps are you using..you should use many step varing the depht of penetration..

or you can try the follow, create one step with the hollow cylinder penetrated totally and control the time of penetration, you can use very small time increment for this purpose..

 

[Geotech2011]

Hi,
Thanks for your message. I define two steps: 1- Geostatic 2- soil
. However the simulation says error message ( fix time increment is too large ). I was wondering if you could explain that how can I define many step varying the depth of penetration and how can I control the time of penetration.
I'll be grateful if you could let me know do you have experience in simulation penetration pile into the soil or hollow cylinder into the soil. Many thanks.