Waves in periodic dissipative laminate metamaterial generated by plate impact

Behavior of short and long high amplitude pulses on an Al-W composite with cylindrical inclusions

“…At a macroscopic level both the materials are comparable having the same volume content of Al and W. It is expected that the resulting waves in these materials are going to be different due to the different geometry of the components. Nevertheless, we expect that the main features of waves (their nature and characteristic width and speed) in the composites with cylindrical inclusions might be determined by a balance of nonlinearity and dispersion as was the case for laminates [9][10][11].…”

“…The Al flyer plate with velocity 2,800 m/s and thickness 8 mm created relatively short incoming pulse. It is known from previous work [9,10] that a laminate loaded by a high-amplitude pulse with duration in the order of magnitude similar to t c generates an attenuating solitary-like pulse. Fig.…”

“…It should be mentioned that heterogeneous materials (e.g., porous, granular, laminates) require much longer propagation distance, depending on material mesostructure, to establish a steady state [7,8]. In [9][10][11] numerical calculations demonstrated that one of the most important factors, determining the nature of the traveling pulse in the laminate Al-W, was the ratio of the characteristic time of wave propagation through unit cell (t c ) to the duration of the incoming pulse. At small value of this ratio, the impact resulted not in expected shock wave, but in a quasistationary, weakly attenuating solitary like wave [9,10], which structure was determined by balance of nonlinearity and dispersion, and not by balance of nonlinearity and dissipation as in homogenous materials.…”

“…In [9][10][11] numerical calculations demonstrated that one of the most important factors, determining the nature of the traveling pulse in the laminate Al-W, was the ratio of the characteristic time of wave propagation through unit cell (t c ) to the duration of the incoming pulse. At small value of this ratio, the impact resulted not in expected shock wave, but in a quasistationary, weakly attenuating solitary like wave [9,10], which structure was determined by balance of nonlinearity and dispersion, and not by balance of nonlinearity and dissipation as in homogenous materials. It was also found [11] that in laminate Al-W composite the structure of the high amplitude shock wave and maximum strain rate is also determined by the interplay between nonlinearity (mainly caused by Al) and dispersion (due to periodic mesostructure) even when dissipation is considered.…”

“…The main objective is investigation of the role of mesostructure on pulse formation and propagation. The material has the same macroscopic characteristics as the previously studied Al-W laminate [9][10][11]. We present numerical comparisons of the pulses that were formed and traveled inside these materials.…”