Hi everyone,
I am using ABAQUS to simulate the soil earth pressure around a buried concrete pipe. Based on reading different threads posted. I knew that there are two ways to simulate the process of excavation and the pipe placement and backfilling.
The first method is to use the ELEMENT COPY command where you duplicate two sets of the elements where the first is assigned the original soil propeties and the copied sets will be assigned the backfilling material properties and the concrete pipe properties. After the MODEL CHANGE command will be used to deactivate and activate elements based on the construction sequence.... This method works for my problem.
The other technique is to use the FIELD VARIABLE where the different materials will be assigned different field variable value. Then the material properties will be changed based on the construction sequence. This method never works for my case when The concrete pipe material is assigned as the material properties and the element are activated . There are always different errors one is TIME INCREMENT REQUIRED IS LESS THAN THE MINIMUM SPECIFIED. If I reduce the minimum value in the model. ANOTHER ERROR REVEALS STATING THAT TOO MANY INCREMENTS ARE REQUIRED. EVEN INCREASING THE THE INCREMENTS NEVER RESULTS IN CONVERGENCE.
I wish if someone can help me with fixing the model or any tips to conduct this analysis.
Thanks in advance for your help and time.
Yours
Sherif Kamel