I am trying to simulate the behavior of helical anchors (also called screw anchors) using PLAXIS 3D and a clay hypoplasticity constitutive model. The helical anchor shaft is simulated as a half cylinder volume element (to obtain moments and forces in a convenient way), covered by a low stiffness plate element at its curved surface. Helical plates (simulated as planar plate-type elements) are attached perpendicularly to the preceding plate. A positive interface is added to the shaft plate while positive and negative interfaces are added to the “helical” plates.
Vertical and lateral forces are applied to the head of the anchor in a displacement-controlled test. The calculation procedure is performed with the Picos solver with the arc-length method setting turned off. Also, I have changed the maximum load fraction step for smaller steps to the program default.
I am experiencing difficulty while loading this element in either direction as the interface experiences excessive deformations followed by a dropdown in the load-displacement plot, no matter the interface resistance parameters.
Is there anything I can do to avoid this kind of issue?hypoclayInterfaceplaxis