As shown in the figure, the hollow cylinder, with a wall thickness of 0.4 m, is placed in the soil, and the prescribed displacement in the z direction is applied to its bottom to be +0.001 m. The resultant force Fz should be positive, but the result is negative. Why is this ?Is it because the bottom node of the cylinder is shared with the soil? Can I solve this problem by adding an interface at the bottom?
Dear Xin Fang,
I would expect so, but with the details given, I cannot explain why.
I did run a simple model with a prescribed displacement, and the sign was correct, as you described.
You mention that the sign was wrong, but is the value incorrect, too?
Note that an interface should be added if you want to include the soil-structure interaction in your simulation. Typically concrete vs soil/rock does require interfaces, but on the other hand I do not really know all the details of what you are trying to achieve.
If you want us to assist you with this question, it is good to check the project directly. Then, one of our support engineers can help you in detail: https://bentleysystems.service-now.com/csp
Dear Stefanos,
Please take a look at my question at your leisure, thank you!
I really want to know how to apply a prescribed surface displacement to the bottom of the cylinder, so that the part of the soil in contact with the bottom of the cylinder does not move up at the same time.