Sandwich Plates Actuated by a Kagome Planar Truss

2004 ◽  
Vol 71 (5) ◽  
pp. 652-662 ◽  
Author(s):  
N. Wicks ◽  
J. W. Hutchinson

Kagome truss plates have properties that suggest they should be uniquely effective as an actuation plane for sandwich plates: a Kagome truss plate has in-plane isotropy, optimal stiffness and strength, and its truss members can be actuated with minimal internal resistance. In this paper, sandwich plates are studied that are comprised of one solid face sheet and one actuated Kagome face sheet joined by a pyramidal truss core. Various aspects of the actuation behavior of these plates are investigated, including internal resistance and strains resulting from actuation and efficiency of actuation. Single and double curvature actuation modes are investigated. Contact is made with analytic results for actuation modes with long wavelength.

Author(s):  
Jiguang Gu ◽  
Nana Yang ◽  
Zhanyi Guo ◽  
Xiongliang Yao

A new technology method is adapted to manufacture carbon fiber lattice sandwich beam with pyramidal truss core. The flat crush test experiment is to test the resistance to compression of the carbon fiber sandwich plate with pyramidal truss core. The result shows that after the pressure head contact the specimens adequately, and the stiffness of structure is the maximum. If the load is continuing increase, the pyramidal truss core may be destroyed, and both sides of the carbon fiber panel begin tottering. It emerges permanent deformation on the structures after an uninstall. The three-point bending test of lattice sandwich beam referred to ASTM C393-00 is designed to research the mechanical properties of face sheet and pyramidal truss core of lattice sandwich beam with theoretical analysis. Load-deflection curves of the middle of lattice sandwich beam in long span and in short span tests are retained, which are applied to obtain flexure stiffness of face sheet and shear strength of pyramidal truss core. It is found that span length has some influence on damage modes of lattice sandwich beam with pyramidal truss core. Debonding between face sheet and lattice core occurs when span is larger and core collapse appears when span is smaller. Crack expansion and fracture of resin base also both emerge in these two damage modes and the crack expansion consists of two different types which are crack expansion inside the resin base and crack expansion from the indenter to the support. Contrast with other lattice sandwich beam with similar or different shapes of core in the other references, the mechanical properties of this lattice sandwich beam by this new fabrication have obvious advantage at the same relative density.


Author(s):  
Wei Zhang ◽  
Qi-liang Wu

In this paper, an extended high-dimensional Melnikov method is used to investigate global and chaotic dynamics of a simply supported 3D-kagome truss core sandwich plate subjected to the transverse and the in-plane excitations. Based on the motion equation derived by Zhang and the method of multiple scales, the averaged equation is obtained for the case of principal parametric resonance and 1:2 sub-harmonic resonance for the first-order mode and primary resonance for the second-order mode. From the averaged equation obtained, the system is simplified to a three order standard form with a double zero and a pair of pure imaginary eigenvalues by using the theory of normal form. Then, the extended Melnikov method is utilized to investigate the Shilnikov-type multi-pulse heteroclinic bifurcations and existence of chaos. The analysis of the extended Melnikov method demonstrates that there exist the Shilnikov-type multi-pulse heteroclinic bifurcations and chaos in the four-dimensional non-autonomous nonlinear system. Finally, the results of numerical simulations also show that for the nonlinear system of simply supported 3D-kagome truss core sandwich plate with the transverse and the in-plane excitations, the Shilnikov-type multi-pulse motion of chaos can happen and further verify the result of theoretical analysis.


2014 ◽  
Vol 118 ◽  
pp. 294-302 ◽  
Author(s):  
I. Ullah ◽  
J. Elambasseril ◽  
M. Brandt ◽  
S. Feih

2021 ◽  
pp. 109963622110288
Author(s):  
Yu-Zhou Wang ◽  
Li Ma

Recently, sandwich structures have been widely used in different fields because of their good mechanical properties, but these structures are weak in acoustic performance. In this paper, by combining pyramidal truss core sandwich structure with frame, a new structure is proposed with both good mechanical properties and excellent acoustic performance at low frequency. An analytical model of the pyramidal truss core sandwich structure with frame is developed to investigate the sound transmission loss (STL) performance. Finite element method (FEM) is also used to investigate the STL performance at low frequency. The effects of the incident wave angle and the geometrical parameters on the STL of the structure are discussed.


2019 ◽  
Vol 22 (2) ◽  
pp. 494-522 ◽  
Author(s):  
Na Zhao ◽  
Renchuan Ye ◽  
Ali Tian ◽  
Jie Cui ◽  
Peng Ren ◽  
...  

To predict the anti-penetration performance of protective structures, the ballistic performance of sandwich plates with steel face-sheet and aluminum foam core, the quasi-static compressive experiments of four different aluminum foam are performed and analyzed. The failure mechanism, mechanical parameters, and modified constitutive model are obtained. The virtual tests using numerical simulation were carried out in different penetration velocities based on quasi-static experimental constitutive parameters. Influence of projectile shape, face-sheet thickness, core thickness, and core densities on the residual velocity and plastic deformation of sandwich plates are discussed, while typical penetration failure modes and deformation mechanism are presented and analyzed. The failure modes of sandwich plates are different for hemisphere- and blunted-nosed projectile and the projectile shape influence is significant for ballistic performance when the penetration velocity approaches ballistic limit. The ballistic limit increases with increase of face-sheet or core thickness, core density and which shows an approximate linear relationship.


Author(s):  
Ting Liu ◽  
Yuansheng Cheng ◽  
Jun Liu ◽  
Ganchao Chen ◽  
Changhai Chen ◽  
...  

Abstract In this paper, the dynamic response of metallic Y-frame core sandwich plates subjected to air blast loading was investigated by employing the LS-DYNA software. The blast wave was generated by the directly detonation of TNT explosives. The deformation/failure modes and associated structural response were identified and analyzed in detail. Main attention was paid to explore the effects of face sheet thicknesses and core web thickness on the deformation response of Y-frame core sandwich plates. A comparison on the blast performance were drawn among the Y-frame core sandwich panel, corrugated core sandwich panel and solid plate in equal areal mass. Numerical results revealed that the Y-frame core sandwich panel experienced indent deformation in the front face, strut buckling in the core and large bending deformation in the back face under the stand-off distance of 100 mm. Increasing the face sheets and core web thicknesses could improve the blast performance of Y-frame core sandwich panels. The deflections of face sheets were sensitive to the variation of front face sheet and core thicknesses. Moreover, Y-frame sandwich panel has comparable anti-blast capacity with the corrugated counterparts and exhibits superior blast resistance than the solid plate.


2000 ◽  
Vol 37 (3) ◽  
pp. 331-341 ◽  
Author(s):  
Terry Hause ◽  
Theodore F. Johnson ◽  
Liviu Librescu
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document