Snap-through system

This work experimentally investigates nonlinear snap-through of a simple class of elastic space trusses in the shape of a regular pyramid. Joints located at the vertices of the base polygon are pinned while the joint at the apex is subjected to a proportionally increasing load acting in the vertical direction. A pyramid truss model has been designed, machined and successfully tested in learning environments to facilitate understanding of the mechanics of truss structures, geometric nonlinearity and stability. Solutions are derived for each load condition under the common hypotheses of linear material law, small or moderate axial deformation in bars and large nodal displacements. For pyramidal truss we determined a function of force in dependence of vertical displacement of uniaxial structural elements for different starting angles at which the uniaxial structural elements were clamped. Accuracy of analytical solution for snap-through system, which we got for different starting angles of uniaxial structural elements, was verified on experimental results obtained in the laboratory.