Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 10 2019 09 27 Numerical and Experimental Study of Energy Absorption Amount of Functionally Graded Honeycomb with Negative Stiffness Property under Quasi-Static Load Numerical and Experimental Study of Energy Absorption Amount of Functionally Graded Honeycomb with Negative Stiffness Property under Quasi-Static Load 2809 2822 3599 10.22060/mej.2019.16382.6351 FA Mahdiyeh Shafipour Department of Mechanical Engineering, University of Birjand, Birjand, Iran Seyed Yousef Ahmadi-Brooghani Assoc. Prof., Mech. Eng., University of Birjand, Birjand , Iran 0000-0002-7468-616X Journal Article 2019 05 20 Functionally graded honeycomb with negative stiffness can be used extensively as an energy absorber because of having two features of negative stiffness and being functionally graded. In this research, the effect of using functionally graded honeycomb with negative stiffness in increasing energy absorption has been considered. In functionally graded honeycomb the thicknesses of structure change gradually in each layer, as a result, each layer has a different stiffness. Negative stiffness honeycomb is a type of energy absorbers that absorb energy by the transition from one buckled shape to another and show snap through- like behavior.In this research, at first quasi-static tests have been carried out on negative stiffness honeycombs with constant thickness. Then finite element model of negative stiffness honeycomb with constant thickness is simulated in ABAQUS software and the results of simulation are compared with experimental results and a good agreement between numerical and experimental results has been observed. Functionally graded honeycomb with negative stiffness then has been modeled numerically. Energy absorption per unit mass of the functionally graded negative stiffness honeycomb has been compared with conventional ones. Based on the results, energy absorption per unit mass in functionally graded honeycomb with negative stiffness increased by 1.57 times. Functionally graded honeycomb with negative stiffness can be used extensively as an energy absorber because of having two features of negative stiffness and being functionally graded. In this research, the effect of using functionally graded honeycomb with negative stiffness in increasing energy absorption has been considered. In functionally graded honeycomb the thicknesses of structure change gradually in each layer, as a result, each layer has a different stiffness. Negative stiffness honeycomb is a type of energy absorbers that absorb energy by the transition from one buckled shape to another and show snap through- like behavior.In this research, at first quasi-static tests have been carried out on negative stiffness honeycombs with constant thickness. Then finite element model of negative stiffness honeycomb with constant thickness is simulated in ABAQUS software and the results of simulation are compared with experimental results and a good agreement between numerical and experimental results has been observed. Functionally graded honeycomb with negative stiffness then has been modeled numerically. Energy absorption per unit mass of the functionally graded negative stiffness honeycomb has been compared with conventional ones. Based on the results, energy absorption per unit mass in functionally graded honeycomb with negative stiffness increased by 1.57 times. https://mej.aut.ac.ir/article_3599_e7e69cdf28f8ce6b69b4e1853ee21bab.pdf