Energy absorption & dynamic properties of SMA lattice structures

Shape memory alloy (SMA) has excellent damping properties and super elasticity, and can be used as vibration and energy absorbing materials for structures. Through the study of the boundary conditions of four side fixation, opposite side fixation, adjacent side fixation and one side fixation, the sinusoidal scanning frequency experiment of SMA double pyramid lattice sandwich plate is studied. With the increase of modal order, the gap is increasing. Through the study of the effects of loading rate, strain amplitude and cycle number on the mechanical properties of SMA bipyramid lattice core, it is found that the energy decreases by 2.44% when the loading speed increases by 2 mm/min, the energy change rate decreases by about 2.5% when the loading frequency increases by ten times, and the energy increases by 20 N center dot mm when the load intensity increases by 100 N. With the increase of loading times and loading rate, the energy absorption capacity of the lattice gradually weakens and tends to be stable. Both simulation and experimental results show that the first three natural frequencies of the structure increase with the increase of boundary fixed conditions. Through numerical simulation, it is found that the loss of core causes the modal shape of the structure to deform and shift to the missing position, and the natural frequency of the structure decreases with the increase of the defect degree. In addition, according to the study of this paper, it can be determined that a certain degree of surface defects will not have a great impact on the overall natural frequency of the structure, which can have a good reference significance in practical use.