The leaves are 8 15 cm (3 6 inches) long and have blades that are hinged along the midline so that the two nearly circular lobes, with spiny teeth along their margins, can fold together and enclose an insect alighting on them.
This experimental observation indicates the formation of a hinge along the depth of the beam.
The elastic elements provide resistance to extension of blade and hinge along the PD and AP axes (see Appendix 3, 'Boundary stresses').
Line up the hinge knuckles along the hinge groove, keeping them straight and level.
When this structure is under mechanical tension, one of the hinges opens along the tensile axis, whereas the other hinge expands in the lateral direction, resulting in a negative Poisson's ratio in the out-of-plane direction [2].
Five internal hinges along fold lines connect the six panels of each cube net; we refer to these connections as edge connections (Fig. 2A).
The edges of each panel featured hinges; internal hinges (along fold lines) connected two panels, while external hinges were at the edges of the panels and did not connect to other panels.
Furthermore, plastic hinge lines along the two diagonals of the target side plate are observed.
The 3-D geometrical collapse mechanism was analyzed by adding the oblique hinge lines along the longitudinal tube within the length of the plastically deformed zone.
