Verification of Stent Mechanical Formulas by “Planar Stent” Experiment

To verify the formulas of elastic radial stiffness and plastic limit pressure of stents, the conception of "planar stent cell" was proposed and a planar stent specimen was produced according to the real curved structure of an intravascular stent. Tensile experiments of "planar stent cell" were then performed using MTS (material test system) equipment, and the experimental pressure-radial curves were compared with the ones predicted by formulas of elastic radial stiffness and plastic limit pressure. The results show that at the elastic stage of stent expansion, the difference of elastic radial stiffness between experimental measurements and formula-calculated values was less than 3%; at the plastic stage, the two curves obtained by experiment and formula were close. The experiments confirmed the accuracy and precision of the two formulas.