Four-strut model with a very detailed masonry hysteresis to represent the diagonal force transmission across the panel, the two struts in each direction transmit some of the force into moments at the joints. A fifth strut, with a bi-linear hysteresis, transmits part of the shear from the top to the bottom of the panel element. In Ruaumoko3D an elastic plate finite element may be added to the panel to provide an out-of-plane stiffness.