Fabrication and vibration isolation capacity of multilayer gradient metallic lattice sandwich panels

Sandwich structures have been widely used in ship, aerospace, vehicle and other fields, due to their lightweight and high load bearing properties. With the rapid development of ship stealth technology, multifunctional structures with lightweight, high loading capacity and excellent vibration reduction performances are urgently needed. To achieve the above multifunctional characteristics, we design and fabricate novel gradient metallic lattice sandwich structures via cutting and snap-fit approach. The gradient is governed by the size of the truss width. Modal test and shaking table sweep frequency test are conducted to characterize the vibration characteristics and vibration isolation performances of the structures. The frequency responses are simulated by modal superposition method, which is verified by experimental results. Furthermore, the influences of interlayer gradient, face sheet thickness and hybrid materials on the vibration performances are explored. Results show that the interlayer gradient and face sheet thickness have significant effects on the vibration characteristics of the present structures. The positive gradient structure has the best vibration isolation performance among all the gradient structures. What’s more, reducing the thickness of the face sheets and using hybrid materials are beneficial to achieve low-frequency vibration isolation effect, which can provide a reference for ship vibration and noise reduction technology.