Numerical Simulation of Low Velocity Impact on Pin-Reinforced Foam Core Sandwich Panel

2017 ◽  
Vol 742 ◽  
pp. 673-680
Author(s):  
M. Adli Dimassi ◽  
Axel S. Herrmann
Keyword(s):  
Sandwich Structures ◽  
Element Model ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Industrial Sectors ◽  
Out Of Plane ◽  
Scale Modelling ◽  
Cohesive Zone Elements ◽  
The Impact

The use of sandwich structures is well established in industrial sectors where high stiffness and strength combined with lightweight are required, like in marine, wind turbine and railway applications. However, the vulnerability of sandwich structures to low-velocity impacts limits its use in primary aircraft structures. Pin reinforcement of the foam core enhances the out-of-plane properties and the damage tolerance of the foam core. In this paper, a finite element model is proposed to predict the impact behaviour of pin-reinforced sandwich structure. An approach based on the building block approach was used to develop the model. Multi-scale modelling in the impact region that considers the delamination of the face sheet using cohesive zone elements was employed to increase the accuracy of the simulation. Impact tests were performed to validate the numerical model. A good agreement between numerical and experimental results in terms of contact-force displacement history and failure mode was found.

Theoretical and experimental analysis for the impact response of glass fibre reinforced aluminium honeycomb sandwiches

2016 ◽  
Vol 20 (1) ◽  
pp. 42-69 ◽  
Author(s):  
Vincenzo Crupi ◽  
Emre Kara ◽  
Gabriella Epasto ◽  
Eugenio Guglielmino ◽  
Halil Aykul
Keyword(s):  
Experimental Data ◽  
Sandwich Structures ◽  
Low Velocity Impact ◽  
Balance Model ◽  
Model Parameters ◽  
Low Velocity ◽  
Internal Damage ◽  
Limit Loads ◽  
Load Carrying ◽  
The Impact

Honeycomb sandwich structures are increasingly used in the automotive, aerospace and shipbuilding industries where fuel savings, increase in load carrying capacity, vehicle safety and decrease in gas emissions are very important aspects. The aim of this study was to develop the theoretical methods, initially proposed by the authors and by other researchers for the prediction of low-velocity impact responses of sandwich structures. The developed methods were applied to sandwich structures with aluminium honeycomb cores and glass-epoxy facings for the assessment of impact parameters and for the prediction of limit loads. The values of model parameters were compared with data reported in literature and the predictions of the limit loads were validated by means of the experimental data. Good achievement was obtained between the results of the theoretical models and the experimental data. The failure mode and the internal damage of the sandwich panels have been investigated using 3D computed tomography, which allowed the evaluation of parameters of energy balance model, and infrared thermography, which allowed the detection of the temperature evolution of the specimens during the tests. The experimental and theoretical results demonstrated that the use of glass-epoxy reinforcement on aluminium honeycomb sandwiches enhances the energy absorption and load carrying capacities.

scholarly journals The low-velocity impact and compression after impact (CAI) behavior of foam core sandwich panels with shape memory alloy hybrid face-sheets

2019 ◽  
Vol 26 (1) ◽  
pp. 517-530 ◽  
Author(s):  
Ye Wu ◽  
Yun Wan
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Sandwich Panels ◽  
Image Correlation ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Velocity Impact ◽  
Compression After Impact ◽  
The Impact

AbstractDue to the properties of shape memory effect and super-elasticity, shape memory alloy (SMA) is added into glass fiber reinforced polymer (GFRP) face-sheets of foam core sandwich panels to improve the impact resistence performance by many researchers. This paper tries to discuss the failure mechanism of sandwich panels with GF/ epoxy face-sheets embedded with SMA wires and conventional 304 SS wire nets under low-velocity impact and compression after impact (CAI) tests. The histories of contact force, absorbed energy and deflection during the impact process are obtained by experiment. Besides, the failure modes of sandwich panels with different ply modes are compared by visual inspection and scanning electron microscopy (SEM). CAI tests are conducted with the help of digital image correlation (DIC) technology. Based on the results, the sandwich panels embedded with SMA wires can absorb more impact energy, and show relatively excellent CAI performance. This is because the SMA wires can absorb and transmit the energy to the outer region of GFRP face-sheet due to the super-elasticity-behavior. The failure process and mechanism of the CAI test is also discussed.

Effect of Foam Core Density and Facesheet Thickness on the Low Velocity Impact Response of Foam Core Sandwich Composites

2000 ◽  
Author(s):  
M. Motuku ◽  
R. M. Rodgers ◽  
S. Jeelani ◽  
U. K. Vaidya
Keyword(s):  
Impact Energy ◽  
Maximum Load ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Core Density ◽  
Failure Characteristics ◽  
Velocity Impact ◽  
The Impact

Abstract The effect of foam core density and facesheet thickness on the low velocity impact response and damage evolution in homogeneous foam core sandwich composites was studied. The failure characteristics, initiation and evolution of damage as well as the effect of impact energy were investigated. A Dynatup 8210 Impact Test Machine was utilized to conduct the low-velocity impact tests. Characterization of the impact response was performed by comparing the impact load histories, impact plots and failure characteristics. Fractography analysis was conducted through the use of scanning electron microscopy (SEM) and optical microscopy. Three types of foam cores with different densities, namely Airlite B12.5, Rohacell IG-71R63 and Airex R63.5 foam cores, were used to study the effect of core density. Considering four groups of facesheets made of different layers of cross-ply carbon prepregs performed the effect of facesheet thickness. For all the facesheet thicknesses (0.011-0.894-cm thick) and impact energy (11-40 J) range considered in this study, the maximum load (Pm), deflection-at-maximum load (δm) and time-to-maximum load (tm) exhibited strong influence or dependence on the type of foam core as opposed to the facesheet thickness. The energy-to-maximum load (Em), total energy absorbed (Et) and total energy-to-impact energy (Et/Eimp) ratio became less sensitive on the foam core density (or type) with increasing facesheet thickness. A transition point from foam core to facesheet controlled impact behavior as a function of impact energy level was observed. The impact parameters varied either linearly or parabolically with impact energy depending on the impact energy level, type of foam core and facesheet thickness. Excellent repeatability of impact data was generally obtained with increase in foam core density.

Study on the Residual Compressive Strength of a Composite Sandwich Panel with Foam Core after Low Velocity Impact

2012 ◽  
Vol 430-432 ◽  
pp. 484-487 ◽  
Author(s):  
Zong Hong Xie ◽  
Jiang Tian ◽  
Jian Zhao ◽  
Wei Li
Keyword(s):  
Compressive Strength ◽  
Failure Criterion ◽  
Sandwich Panel ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Velocity Impact ◽  
Residual Compressive Strength ◽  
Composite Sandwich ◽  
The Impact

The residual compressive strength of a foam core sandwich panel after low-velocity impact was studied by using experimental and analytical methods. The test specimens were compressed uniaxially after they were subjected to a low-velocity-impact. From the observation in the test, one can conclude that the subsequent core crushing around the impact region is the major failure mode in the sandwich structure. A failure criterion named Damage Propagation Criterion was proposed to predict the residual compressive load bearing capability of the low-velocity impacted composite sandwich panel. The characteristic value used in this failure criterion can be calculated by an analytical model developed or by conducting the Sandwich Compression after Impact test.

Numerical Simulation of Compression-After-Impact Process of Composite Laminates

2012 ◽  
Vol 525-526 ◽  
pp. 265-268
Author(s):  
Biao Li ◽  
Ya Zhi Li ◽  
Xi Li ◽  
Zhen Hua Yao
Keyword(s):  
Composite Laminates ◽  
Element Model ◽  
Low Velocity Impact ◽  
Cohesive Elements ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Process ◽  
Compression After Impact ◽  
Out Of Plane ◽  
Plane Compression

The residual compressive strength of composite laminates subjected to low-velocity impact (CAI) was analyzed using the ABAQUS/Explicit package through a two-step calculation. The finite element model was composed of solid elements and interfacial cohesive elements. The out of plane low-velocity impact process was simulated in the first step and the results of which were taken as the input for the second step of the in-plane compression, until the collapse of the laminate. The usefulness of the explicit solution algorithm in dealing with the quasi-static procedure of the in-plane compression was investigated by examining the effect of different initial velocities of the compression loading on CAI values. The simulation results agree well with the experimental results.

The Sensitivity of the Foam-Core Parameters under Impact Loading

2012 ◽  
Vol 525-526 ◽  
pp. 289-292
Author(s):  
Fei Xu ◽  
Min Ge Duan
Keyword(s):  
Impact Resistance ◽  
Low Velocity Impact ◽  
Core Material ◽  
Foam Core ◽  
Sandwich Composites ◽  
Low Velocity ◽  
Fea Model ◽  
The Face ◽  
Damage Process ◽  
The Impact

This study presents the numerical investigation of the low-velocity impact for the foam-cored sandwich composites. Firstly, the proposed FEA model is validated by comparing the results between simulation and test. The user subroutine VUMAT and the crushable foam model are chosen to describe the damage of the face sheets and the characteristics of the foam material, respectively. The detailed damage process of the sheets and the foam is clearly shown. The sensitivity of seven parameters related to foam-core material are studied. It is shown that the yield strength, the fracture strain and the fracture displacement have significant effects on the impact-resistance of the foam-cored sandwich composites.

scholarly journals Experimental analysis of impact and post-impact behaviour of inserts in Carbon sandwich structures

2017 ◽  
Vol 21 (1) ◽  
pp. 135-153 ◽  
Author(s):  
Laurent Mezeix ◽  
Simon Dols ◽  
Christophe Bouvet ◽  
Bruno Castanié ◽  
Jean-Paul Giavarini ◽  
...  
Keyword(s):  
Sandwich Structures ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Failure Patterns ◽  
Impact Tests ◽  
Compression After Impact ◽  
Post Impact ◽  
Pull Through ◽  
Failure Scenario ◽  
The Impact

In aeronautics, honeycomb sandwich structures are widely used for secondary structures such as landing gear doors, flaps or floors, and for primary structures in helicopters or business jets. These structures are generally joined by using local reinforcements of the insert type. In the present study, 50 J low velocity impact tests were performed on inserts using a drop-weight device and the impact response and failure patterns were analysed. Impacted specimens were then pull-through tested to failure. Some of the tests were stopped before final failure in order to obtain precise details on the failure scenario. It was shown that, in the cases studied, the residual strength after impact was very high (about 90%) in comparison to the large reductions habitually observed in compression after impact tests.

scholarly journals Numerička analiza dinamičkog ponašanja kompozitnog saćastog panela ispunjenog cevčicama pod dejstvom udarnog opterećenja male brzine u ravni panela

2021 ◽  
Vol 49 (4) ◽  
pp. 969-976
Author(s):  
Younes Djemaoune ◽  
Branimir Krstić ◽  
Boško Rašuo ◽  
Stefan Rašić ◽  
Daniel Radulović ◽  
...  
Keyword(s):  
Model Simulation ◽  
Numerical Study ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Explicit Finite Element ◽  
Impact Performance ◽  
Honeycomb Sandwich ◽  
Out Of Plane ◽  
Plane Direction ◽  
The Impact

Honeycomb sandwich structures, composed of many regularly arranged hexagonal cores and two skins, show excellent impact performance due to strong energy absorption capability under impact loads. In this paper, a numerical study of low velocity impact on honeycomb sandwich panels filled with circular tubes in the in-plane direction was performed. To calibrate the numerical model, simulation results in the out-of-plane direction are compared with the experimental ones. The numerical modelling of the drop weight test was carried out using the nonlinear explicit finite element code Abaqus/Explicit. The impact responses are presented as the contact force between the impactor and the panel versus the time. It was concluded that the filled honeycomb panel absorbs the same amount of impact energy in a shorter time than an empty one. In addition, the deflections of the front and back face-sheets are investigated. The panel degradation and the stress distribution during the crushing are also discussed.

The perforation resistance of sandwich structures subjected to low velocity projectile impact loading

2012 ◽  
Vol 116 (1186) ◽  
pp. 1247-1262 ◽  
Author(s):  
J. Zhou ◽  
Z. W. Guan ◽  
W. J. Cantwell
Keyword(s):  
Sandwich Structures ◽  
Sandwich Panels ◽  
Impact Testing ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Analysis Package ◽  
The Impact

Abstract This article presents the findings of a study to investigate the impact perforation resistance of sandwich structures. The dynamic response of sandwich panels based on PVC foam cores has been evaluated by determining the energy to perforate the panels. The impact response of the sandwich structures was predicted using the finite element analysis package Abaqus/Explicit. The validated FE models were also used to investigate the effect of oblique loading and to study the impact response of sandwich panels subjected to a pressure differential equivalent to flying at an altitude of 10,000m. Low velocity impact testing has shown that the energy to perforate the sandwich panels is dependent on the properties of the core. It has been shown that increasing the density of the crosslinked PVC foams by a factor of two yielded a 600% increase in the perforation resistance of the sandwich structures. At higher densities, the crosslinked foam sandwich structures offered a superior perforation resistance to the linear PVC structures. The numerical analysis accurately predicted the perforation energies of the sandwich panels, as well as the prevailing failure mechanisms following impact. Finally, it has been shown that sandwich panels impacted at high altitude offer a similar perforation resistance to those tested at sea level.

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