Response of aluminum corrugated sandwich panels under foam projectile impact – Experiment and numerical simulation

2016 ◽  
Vol 19 (5) ◽  
pp. 595-615 ◽  
Author(s):  
Xin Li ◽  
Shiqiang Li ◽  
Zhihua Wang ◽  
Jinglei Yang ◽  
Guiying Wu
Keyword(s):  
Impact Velocity ◽  
Aluminum Foam ◽  
Sandwich Panels ◽  
Face Sheet ◽  
Front Face ◽  
Comparable Amount ◽  
Projectile Impact ◽  
The Face ◽  
Core Height ◽  
The Impact

The paper studied the dynamic response of square aluminum corrugated sandwich panels under projectile impact. The aluminum foam projectile was utilized to apply the impulse on the sandwich panels. In order to increase the applied impulse under controlled impact velocity ( V < 200 m/s), a cylindrical Nylon mass was adhered to the back of foam projectile. Corrugated sandwich panels with two different configurations were tested and their typical deformation modes were obtained in the experiment. Based on the experiment, corresponding numerical simulations were presented. The energy absorption and deformation mechanism of corrugated sandwich panels were studied through the simulation. The influence of impact velocity, thickness of face sheet and wall thickness of corrugated core were discussed. The results indicated that the corrugated sandwich panels with smaller core height produce larger deformation than the panels with larger core height. The face sheets of corrugated sandwich panel absorbed comparable amount of energy with the corrugated core. The velocity histories show that under the combined action of aluminum foam projectile and nylon back mass, a second peak velocity of front face sheet can be produced during the impact process, which is defined as “accelerating impact stage” in current study. The influence of “accelerating impact stage” to the response of structures is sensitive to the impact velocity.

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.

Numerical Modelling of Impact Behavior of Composite Sandwich Panel With Honeycomb Core

2019 ◽  
Author(s):  
Shah Alam ◽  
Aakash Bungatavula
Keyword(s):  
Sandwich Panel ◽  
Sheet Thickness ◽  
Face Sheet ◽  
Honeycomb Core ◽  
Impact Performance ◽  
Composite Sandwich ◽  
The Core ◽  
The Face ◽  
Core Height ◽  
The Impact

Abstract The goal of this paper is to find the best impact response of the composite sandwich panels with honeycomb core. The focus of the study is to find the effects of changing the face sheet thickness and the core height of the sandwich panel subjected to variable velocities on impact performance. Initially, honeycomb core sandwich panel with 1mm thick face sheet is modelled in Abaqus/explicit to calculate the energy absorption, residual velocity, and deformation at four different velocities. Then, the process is repeated by changing the face sheets thickness to 2mm and 3mm to see the effects of changing the thickness on the impact performance of a composite sandwich panel. The honeycomb core height is also changed to see its effect on the performance. In all models, Al 7039 is used in the core and T1000G is used in the face sheets.

Dynamic response of circular metallic sandwich panels under projectile impact

2016 ◽  
Vol 19 (5) ◽  
pp. 572-594 ◽  
Author(s):  
Peiwen Zhang ◽  
Xin Li ◽  
Tao Jin ◽  
Zhihua Wang ◽  
Longmao Zhao
Keyword(s):  
Dynamic Response ◽  
Sandwich Structure ◽  
Impact Resistance ◽  
Sandwich Panels ◽  
Face Sheet ◽  
Foil Thickness ◽  
Geometrical Configuration ◽  
Projectile Impact ◽  
Back Face ◽  
The Impact

The dynamic response of circular sandwich panels with aluminium honeycomb and corrugated cores under projectile impact was investigated experimentally and numerically. Impulse loaded on the panel was controlled by projectile launching velocity and the deformation process of sandwich panels was recorded by a high-speed camera in the experiments. Typical deformation/failure modes of face-sheets and cores were obtained and analysed. The back face-sheet deflections and strain histories of face-sheets were measured and discussed. A parametric study was conducted by LS-DYNA 3D to analyse the effect of geometrical configuration on energy absorption mechanism and back face-sheet permanent deflection of circular sandwich panels. The results indicated that the impact resistance of the structure was sensitive to geometrical configuration. Increasing face-sheet thickness and core relative density significantly improved sandwich structure impact resistance. Increasing foil thickness improved the panel impact resistance more efficiently than decreasing wall side length. The results have important reference value to guide engineering application of the sandwich structure subjected to impact loading.

Ballistic impact behaviors of aluminum alloy sandwich panels with honeycomb cores: An experimental study

2016 ◽  
Vol 20 (7) ◽  
pp. 861-884 ◽  
Author(s):  
QN Zhang ◽  
XW Zhang ◽  
GX Lu ◽  
D Ruan
Keyword(s):  
Aluminum Alloy ◽  
Energy Absorption ◽  
Impact Velocity ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Face Sheet ◽  
Ballistic Limit ◽  
Core Density ◽  
Impact Tests ◽  
Honeycomb Cores

To study the protection property of aluminum alloy sandwich panels with honeycomb cores under the attack of bullets or debris, quasi-static perforation, and ballistic impact tests were conducted, in which the thicknesses of the face sheet and core were 0.5–2.0 and 12.7 mm, respectively, while projectiles with diameter 7.5 mm and impact velocity 50–220 m/s were employed. Based on the experiments, the influences of impact velocity, face sheet thickness, core density as well as the nose shape of the projectiles were investigated. The results showed that in the impact tests, the sandwich panels dissipated much more energy than those in quasi-static perforation tests, and the energy absorption and ballistic limit of the sandwich panels increased with the increase of impact velocity. The influence of face sheet thickness was more remarkable than the core density, which was due to the relative density of honeycomb is too small. Although the increase of core density could induce the increase of energy absorption, this effect is more effective for thinner face sheet. Moreover, under the same impact velocity about 200 m/s and face sheet thickness 1.0 mm, the ballistic limit for conical-nosed projectile is highest, while it is lowest for flat-nosed projectile.

Dynamic Response of Metallic Y-Frame Core Sandwich Panels Subjected to Air Blast Loading: Numerical Investigation

2019 ◽  
Author(s):  
Ting Liu ◽  
Yuansheng Cheng ◽  
Jun Liu ◽  
Ganchao Chen ◽  
Changhai Chen ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Face Sheet ◽  
Front Face ◽  
Sandwich Plates ◽  
Air Blast ◽  
Solid Plate ◽  
Blast Performance ◽  
Air Blast Loading

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.

Dynamic Response of Sandwich Panels With a Flexible Core Under Simultaneous Low-Velocity Impacts of Multiple Small Masses

2006 ◽  
Author(s):  
K. Malekzadeh ◽  
M. R. Khalili
Keyword(s):  
Dynamic Response ◽  
Plate Theory ◽  
Sandwich Panels ◽  
Shear Deformation Theory ◽  
Core Layer ◽  
Contact Forces ◽  
Low Velocity ◽  
The Face ◽  
The Impact ◽  
Flexible Core

Dynamic response of sandwich panels with a flexible core under simultaneous low-velocity impacts of multiple small masses has investigated in this paper. The contact forces between the panel and the impactors are treated as the internal forces of the system. Shear deformation theory is used for the face sheets while three dimensional elasticity is used for the soft core. The fully dynamic effects of the core layer and the face-sheets are considered in this study. The results in multiple mass impacts over sandwich panels are presented based on proposed improved higher-order sandwich plate theory (IHSAPT). As no literature could be found on the impact of multiple impactors over sandwich panels, the present formulation is validated indirectly by comparing the response of two cases of double small masses and single small mass impacts based on Olsson’s wave control principle.

Failure mode maps for four-point-bending of hybrid sandwich structures with carbon fiber reinforced plastic face sheets and aluminum foam cores manufactured by a polyurethane spraying process

2017 ◽  
Vol 21 (8) ◽  
pp. 2654-2679 ◽  
Author(s):  
Peter Rupp ◽  
Peter Elsner ◽  
Kay A Weidenmann
Keyword(s):  
Carbon Fiber ◽  
Failure Mode ◽  
Aluminum Foam ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Bending Tests ◽  
The Core ◽  
Four Point Bending ◽  
The Face ◽  
Spraying Process

This work focuses on failure mode maps of sandwich panels exposed to bending load, which were produced using a polyurethane spraying process. This process allows for an automated production of sandwich panels omitting a separate bonding step of the face sheets to the core. The investigated sandwich panels consisted of carbon fiber reinforced face sheets in various configurations, and four different core structures of aluminum foam or Nomex honeycomb. After production, measurements of the pores inside the core foam structures, the fiber package thickness inside the face sheets, and the density homogeneity of the core structure were made using X-ray computed tomography. The failure mode maps were based on the individual mechanical properties of the face sheets and the core, determined by mechanical testing. The critical forces determining the failure modes were partially modified to fit the application on foam core structures and face sheets with a porous matrix. The verification of the failure modes was performed with four-point bending tests. Since all tested configurations of sandwich specimens were produced using the same process route, the applied models for the creation of the failure mode maps could be verified for numerous parameter combinations. Except for two parameters with inconstant properties, the failure modes determined by the failure mode maps matched the observed failure modes determined by the bending tests.

High Velocity Impact Deformation of a Laser Welded Sandwich Panels

2013 ◽  
Vol 742 ◽  
pp. 19-23
Author(s):  
Yu Ping Sun ◽  
Zhi En Du ◽  
Hui Li ◽  
Jin Mei Li
Keyword(s):  
Impact Velocity ◽  
Sandwich Panel ◽  
Shear Failure ◽  
Sandwich Panels ◽  
Bottom Plate ◽  
High Velocity Impact ◽  
Impact Deformation ◽  
High Impact Velocity ◽  
The Impact ◽  
Partial Destruction

Underwater impact and explosion are the main methods that destroy the warships, it cause attention of countries with marine power. The all metal laser welded sandwich panels has the higher stiffness and better mechanical behavior, and be used to protect for warships against impact. This paper analyzed the displacement of sandwich panel on light impact object with different impact velocity , which show that: (1) The top plate penetrate at the impact velocity of 185m/s, then the bottom plate is penetrate when the impact velocity approaches to 275m/s. (2) The displacement of top plate is confined to the scope of 60mm along x-axis and 40mm along Y-axis from the impacting point at a high impact velocity, the failure mode of sandwich panel is serious partial destruction and obvious shear failure.

scholarly journals Why Impacted Yarns Break at Lower Speed Than Classical Theory Predicts

2011 ◽  
Vol 78 (5) ◽  
Author(s):  
James D. Walker ◽  
Sidney Chocron
Keyword(s):  
Impact Velocity ◽  
Classical Theory ◽  
Impact Speed ◽  
Projectile Impact ◽  
Theoretical Maximum ◽  
Theory Result ◽  
Single Yarn ◽  
The Impact ◽  
Good Agreement ◽  
Minimum Impact

Fabrics are an extremely important element of body armors and other armors. Understanding fabrics requires understanding how yarns deform. Classical theory has shown very good agreement with the deformation of a single yarn when impacted transversely. However, the impact speed at which a yarn breaks based on this classical theory is not correct; it has been experimentally noted that yarns break when impacted at a lower speed. This paper explores the mechanism of yarn breakage. The problem of the transverse strike of a yarn by a flat-faced projectile is analytically solved for early times. It is rigorously demonstrated that when a flat-faced projectile strikes a yarn, the minimum impact speed that breaks the yarn will always be at least 11% less than the classical-theory result. It is further shown that when the yarn in front of the projectile “bounces” off the projectile face due to the impact, the impact speed that breaks the yarn is further reduced. If the yarn bounces elastically off the projectile face at twice the impact velocity (the theoretical maximum), there is a 40% reduction in the projectile impact speed that breaks the yarn.

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