Expand description
Uniaxial material probe: one persistent unit zero-length spring driven by
prescribed displacement (Analysis::step_prescribed), the equivalent of
OpenSees’ sp-constrained zeroLength model. Strain is the relative
displacement node2.x - node1.x and stress is the material’s tensile
resisting force, Domain::reaction at node 2 (OpenSees’ -nodeReaction(1, 1)).
Unit area and gauge length are implicit.