[Version 2018.01.00] Bug fix in Node-Face constraint list (e.g. SlidingWithFriction).

[zhouxinwei]

When the node-face constraint is initialized, the projected node onto the face is misplaced (but still within the face). The bug shows up when the relative position of the node and the face is changed significantly during a simulation. For example, in an unconfined compression test of a concrete cylinder (modeled by LDPM) where the specimen is placed between two loading platens, if the interface between the loading platen and the specimen is modeled using Node-Face constraint list (e.g. SlidingWithFriction formulation), the bug manifests itself during post-peak when the specimen starts breaking, see the picture below (blue VS green curve).

unconfined-compression.png (1.74 MiB) Viewed 6634 times