Design and modelling of auxetic double arrowhead honeycomb core sandwich panels for performance improvement under air blast loading

2020 ◽  
pp. 109963622093556 ◽  
Author(s):  
Ganchao Chen ◽  
Yuansheng Cheng ◽  
Pan Zhang ◽  
Jun Liu ◽  
Changhai Chen ◽  
...  
Keyword(s):  
Relative Density ◽  
Performance Improvement ◽  
Energy Absorption ◽  
Large Scale ◽  
Front Face ◽  
Horizontal Distance ◽  
Honeycomb Core ◽  
Deformation Response ◽  
Back Face ◽  
Global Deformation

In the present study, a 2D-based large-scale metallic auxetic double arrowhead honeycomb core sandwich panel (DAHSP) was proposed and its deformation response, energy dissipation characteristics and associated mechanisms under air blasts were investigated using a validated numerical model. It aims at the performance improvement of DAHSPs through the design of core relative density with respect to different strategies. The DAHSPs considered mainly experienced a local dome superimposed upon global deformation of front face and global deformation of back face, while the core webs were heavily buckled and progressively collapsed. The results confirmed the material concentration effect of DAH cores induced by the negative Poisson’s ratio (NPR). It was found that the panel deformation response was highly related to their deformation/failure mechanisms. Relative to core web thickness, the increase of number of core layers led to a more remarkable decrease in permanent deflections. However, the decline of inclined angles not always reduced the back face deflection due to the competition between enhanced bending stiffness and deteriorated local contact force. An ideal means to decrease the panel deformation is to enlarge the inclined angles at low relative density but to decrease the horizontal distance when the relative density increases to a high level. The panel with thinner core webs at low relative density and the panel with narrowed inclined angles at high relative density is more beneficial to plastic energy absorption. In addition, a core configuration with a thinner tendon but a thicker stuffer promoted the exploitation of NPR and further improved the panel energy absorption.

Impact Analysis of Honeycomb Core Sandwich Panels

2020 ◽  
Author(s):  
Shah Alam ◽  
Damodar Khanal
Keyword(s):  
Sandwich Panels ◽  
Sheet Thickness ◽  
Composite Panel ◽  
Face Sheet ◽  
Impact Behavior ◽  
Front Face ◽  
Geometrical Parameters ◽  
Honeycomb Core ◽  
Back Face ◽  
The Impact

Abstract The goal of this paper is to analyze the impact behavior among geometrically different sandwich panels shown upon impact velocities. Initially, composite model with aluminum honeycomb core and Kevlar (K29) face sheets is developed in ABAQUS/Explicit and different impact velocities are applied. Keeping other parameters constant, model is simulated with T800S/epoxy face sheets. Residual velocities, energy absorption (%), and maximum deformation depth is calculated for sandwich panel for both models at five different velocities by executing finite element analysis. Once the better material is found for face sheets, process is extended by varying the ratio of front face sheet thickness to back face sheet thickness keeping other geometrical parameters constant to find the better geometry. Also, comparison of impact responses of sandwich composite panel on different ratio of front face sheet thickness to back face sheet thickness is done and validated with other results available in literature.

scholarly journals Effects of cell aspect ratio and relative density on deformation response and failure of honeycomb core structure

2020 ◽  
Vol 7 (1) ◽  
pp. 015332 ◽  
Author(s):  
Muhammad Salman Khan ◽  
Seyed Saeid Rahimian Koloor ◽  
Mohd Nasir Tamin
Keyword(s):  
Aspect Ratio ◽  
Relative Density ◽  
Core Structure ◽  
Honeycomb Core ◽  
Deformation Response

Numerical investigation on the dynamic response of foam-filled corrugated core sandwich panels subjected to air blast loading

2017 ◽  
Vol 21 (3) ◽  
pp. 838-864 ◽  
Author(s):  
Yuansheng Cheng ◽  
Tianyu Zhou ◽  
Hao Wang ◽  
Yong Li ◽  
Jun Liu ◽  
...  
Keyword(s):  
Total Energy ◽  
Energy Absorption ◽  
Sandwich Panels ◽  
Blast Loading ◽  
Front Face ◽  
Back Side ◽  
Air Blast ◽  
Foam Filled ◽  
Blast Performance ◽  
Air Blast Loading

The ANSYS/Autodyn software was employed to investigate the dynamic responses of foam-filled corrugated core sandwich panels under air blast loading. The panels were assembled from metallic face sheets and corrugated webs, and PVC foam inserts with different filling strategies. To calibrate the proposed numerical model, the simulation results were compared with experimental data reported previously. The response of the panels was also compared with that of the empty (unfilled) sandwich panels. Numerical results show that the fluid–structure interaction effect was dominated by front face regardless of the foam fillers. Foam filling would reduce the level of deformation/failure of front face, but did not always decrease the one of back face. It is found that the blast performance in terms of the plastic deflections of the face sheets can be sorted as the following sequence: fully filled hybrid panel, front side filled hybrid panel, back side filled hybrid panel, and the empty sandwich panel. Investigation into energy absorption characteristic revealed that the front face and core web provided the most contribution on total energy absorption. A reverse order of panels was obtained when the maximization of total energy dissipation was used as the criteria of blast performance.

The turning couples on an elliptic particle settling in a vertical channel

1994 ◽  
Vol 271 ◽  
pp. 1-16 ◽  
Author(s):  
Peter Y. Huang ◽  
Jimmy Feng ◽  
Daniel D. Joseph
Keyword(s):  
Shear Stress ◽  
Vortex Shedding ◽  
Stokes Equations ◽  
Vertical Channel ◽  
Navier Stokes ◽  
Front Face ◽  
Two Dimensional ◽  
Navier Stokes Equations ◽  
Back Face ◽  
The One

We do a direct two-dimensional finite-elment simulation of the Navier–Stokes equations and compute the forces which turn an ellipse settling in a vertical channel of viscous fluid in a regime in which the ellipse oscillates under the action of vortex shedding. Turning this way and that is induced by large and unequal values of negative pressure at the rear separation points which are here identified with the two points on the back face where the shear stress vanishes. The main restoring mechanism which turns the broadside of the ellipse perpendicular to the fall is the high pressure at the ‘stagnation point’ on the front face, as in potential flow, which is here identified with the one point on the front face where the shear stress vanishes.

Effect of Fracture on Crushing of Ship Structures

2003 ◽  
Vol 47 (03) ◽  
pp. 194-207 ◽  
Author(s):  
W. Abramowicz ◽  
B. C. Simonsen
Keyword(s):  
Energy Absorption ◽  
Large Scale ◽  
Plate Thickness ◽  
Parent Material ◽  
Experimental Series ◽  
Ductile Material ◽  
Structural Components ◽  
Ship Structures ◽  
Material Response ◽  
Axial Crushing

This paper is concerned with loads and energy absorption during crushing of ship structures. Particular focus is on the effect of fracture of welds or parent material on the energy absorption of typical structural subassemblies of ships during deep collapse. The paper presents experiments and theories on the crushing response of typical strength elements. The theories are derived for an infinitely ductile material response and then consistently modified to include the effect of fracture. Theoretical formulas are compared with results of large-scale experiments performed at the Technical University of Denmark. The experimental series included 24 × and T aluminum and steel specimens scaled according to geometrical similarity and with a plate thickness varying between 2 and 20 mm. Theories and experiments demonstrate that the effect of fracture may be very significant for the loads and energy absorption in axial crushing of typical ship structural components. This effect of fracture has been neglected in previously published studies of bow crushing mechanics.

Large-scale organizational performance improvement

1999 ◽  
Vol 38 (10) ◽  
pp. 24-28
Author(s):  
Rudy Pilotto ◽  
Jonathan O'Donnell Young
Keyword(s):  
Organizational Performance ◽  
Performance Improvement ◽  
Large Scale

Four-Point Bending of Metallic I-Core Sandwich Beams With Longitudinal Girder

2019 ◽  
Author(s):  
Wenwei Hu ◽  
Jun Liu ◽  
Pan Zhang ◽  
Yuansheng Cheng
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Numerical Model ◽  
Sandwich Structure ◽  
Front Face ◽  
Beam Structure ◽  
Hull Structure ◽  
Bending Load ◽  
Back Face ◽  
Bending Loads

Abstract I-core sandwich structure has great potential in the application of hull structure construction due to its high specific strength and relatively simple manufacturing process. The topic on the study of mechanical properties of I-core sandwich structure under bending loads is of interest to structural designers since the structure is often subjected to bending loads in engineering applications. In this paper, a metallic I-core sandwich beam with longitudinal girder was designed and manufactured using laser welding technique, and finally tested under four-point bend loading. The elastic-plastic behaviors and the ultimate load carrying capacity of this novel beam structure were obtained. A numerical model was developed to investigate the mechanical properties of this novel beam structure by finite element method. The results of the numerical model were compared with experimental data. Stress components of the front face and back face in the failure process were analyzed and discussed to investigate the failure of them. Results showed that the huge local bending stresses of plate caused the failure of the front face and back face. Finally, an improved scheme for the test was proposed to provide a pure bending load, which was proved by finite element simulation. All the findings aim to guide the engineering application of this structure.

Closed-Loop Control of Weld Penetration Using Front-Face Vision Sensing

1993 ◽  
Vol 207 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Y M Zhang ◽  
R Kovacevic ◽  
L Wu
Keyword(s):  
Arc Welding ◽  
Dynamic Modelling ◽  
Front Face ◽  
Weld Penetration ◽  
Loop Control ◽  
Vision Sensing ◽  
Gas Tungsten Arc ◽  
Full Penetration ◽  
Back Face ◽  
The Relationship

Feedback control of weld penetration based on a front-face sensor is a challenging problem in the field of welding. A novel vision-based approach is proposed in this paper for full penetration control of the gas tungsten arc welding (GT AW). Owing to the relationship between the front-face weld geometry and back-face weld width (representation of the full penetration state), which has been reported earlier by the present authors, it is possible to use the front-face geometry as feedback of full penetration. Based on the dynamic modelling and the analysis of accepted adaptive control algorithms, an adaptive predictive decoupling controller is developed. Simulations and experiments under a variety of welding conditions have been conducted to verify the effectiveness of the proposed approach and controller.

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