Solitary wave propagation in a two-dimensional lattice

Wave Motion ◽  
2018 ◽  
Vol 83 ◽  
pp. 12-24 ◽  
Author(s):  
Anna Vainchtein
1979 ◽  
Vol 20 (4) ◽  
pp. 1398-1409 ◽  
Author(s):  
Jad H. Batteh ◽  
John D. Powell

Author(s):  
Jiahong Hou ◽  
Zhijun Zhang ◽  
Dong Li

Abstract This paper proposed a two-dimensional lattice structure with a nested core. The bandgap distribution and the anisotropy of phase velocity and group velocity were studied based on Bloch’s theorem and finite element method. The effects of eccentric ratio (e) and rotation angle (θ) of dual-phase structure on the bandgap distribution were investigated, and the anisotropy was studied via phase velocity and group velocity. The structure of (e) = 0.3 displayed the maximum total bandgap width. With (θ) increasing, the total bandgap widths of structures of different (e) all increased apparently and the low-frequency bandgap properties were improved. The phase velocity and group velocity of (e) = 0 displayed strong anisotropy, and the anisotropy was tuned by tuning (θ). Furthermore, the group velocity of the eighth mode displayed high directional wave propagation. For practical application, a single-phase structure was proposed and analyzed. Through additive manufacturing technology, the single-phase structure was prepared and tested by a low amplitude test setup. The experimental results displayed a good agreement with numerical results which demonstrated high directional propagation. This finding may pave the way for the practical application of the proposed lattice metamaterial in terms of wave filtering.


1997 ◽  
Author(s):  
E. Longatte ◽  
P. Lafon ◽  
S. Candel ◽  
E. Longatte ◽  
P. Lafon ◽  
...  

1991 ◽  
Vol 06 (39) ◽  
pp. 3591-3600 ◽  
Author(s):  
HIROSI OOGURI ◽  
NAOKI SASAKURA

It is shown that, in the three-dimensional lattice gravity defined by Ponzano and Regge, the space of physical states is isomorphic to the space of gauge-invariant functions on the moduli space of flat SU(2) connections over a two-dimensional surface, which gives physical states in the ISO(3) Chern–Simons gauge theory. To prove this, we employ the q-analogue of this model defined by Turaev and Viro as a regularization to sum over states. A recent work by Turaev suggests that the q-analogue model itself may be related to an Euclidean gravity with a cosmological constant proportional to 1/k2, where q=e2πi/(k+2).


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3553
Author(s):  
Dengwang Wang ◽  
Yong Gao ◽  
Sheng Wang ◽  
Jie Wang ◽  
Haipeng Li

Carbon/Phenolic (C/P), a typical anisotropic material, is an important component of aerospace and often used to protect the thermodynamic effects of strong X-ray radiation. In this paper, we establish the anisotropic elastic-plastic constitutive model, which is embedded in the in-house code “RAMA” to simulate a two-dimensional thermal shock wave induced by X-ray. Then, we compare the numerical simulation results with the thermal shock wave stress generated by the same strong current electron beam via experiment to verify the correctness of the numerical simulation. Subsequently, we discuss and analyze the rules of thermal shock wave propagation in C/P material by further numerical simulation. The results reveal that the thermal shock wave represents different shapes and mechanisms by the radiation of 1 keV and 3 keV X-rays. The vaporization recoil phenomenon appears as a compression wave under 1 keV X-ray irradiation, and X-ray penetration is caused by thermal deformation under 3 keV X-ray irradiation. The thermal shock wave propagation exhibits two-dimensional characteristics, the energy deposition of 1 keV and 3 keV both decays exponentially, the energy deposition of 1 keV-peak soft X-ray is high, and the deposition depth is shallow, while the energy deposition of 3 keV-peak hard X-ray is low, and the deposition depth is deep. RAMA can successfully realize two-dimensional orthotropic elastoplastic constitutive relation, the corresponding program was designed and checked, and the calculation results for inspection are consistent with the theory. This study has great significance in the evaluation of anisotropic material protection under the radiation of intense X-rays.


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