scholarly journals The Bending Responses of Sandwich Panels with Aluminium Honeycomb Core and CFRP Skins Used in Electric Vehicle Body

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yong Xiao ◽  
Yefa Hu ◽  
Jinguang Zhang ◽  
Chunsheng Song ◽  
Xiangyang Huang ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Vehicle Body ◽  
Stacking Sequence ◽  
Honeycomb Core ◽  
Fibre Direction ◽  
Element Analysis ◽  
Honeycomb Sandwich ◽  
Carbon Fibre Reinforced Plastic

The aim of this paper was to investigate bending responses of sandwich panels with aluminium honeycomb core and carbon fibre-reinforced plastic (CFRP) skins used in electric vehicle body subjected to quasistatic bending. The typical load-displacement curves, failure modes, and energy absorption are studied. The effects of fibre direction, stacking sequence, layer thickness, and loading velocity on the crashworthiness characteristics are discussed. The finite element analysis (FEA) results are compared with experimental measurements. It is observed that there are good agreements between the FEA and experimental results. Numerical simulations and experiment predict that the honeycomb sandwich panels with ±30° and ±45° fibre direction, asymmetrical stacking sequence (45°/−45°/45°/−45°), thicker panels (0.2 mm∼0.4 mm), and smaller loading velocity (5 mm/min∼30 mm/min) have better crashworthiness performance. The FEA prediction is also helpful in understanding the initiation and propagation of cracks within the honeycomb sandwich panels.

Research on Energy Absorption Characteristics of Honeycomb Sandwich Panels

2011 ◽  
Vol 299-300 ◽  
pp. 30-33
Author(s):  
Shu Juan Hou ◽  
Li Li Ren ◽  
Duo Dong
Keyword(s):  
Optimal Design ◽  
Energy Absorption ◽  
Optimization Design ◽  
Sandwich Panels ◽  
Weight Ratio ◽  
Vehicle Body ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Honeycomb Sandwich ◽  
Absorption Characteristics

Due to the excellent mechanical properties combined with high strength to weight ratio, honeycomb sandwich panels (HSP) are used increasingly in aerospace, automobile and marine industries. In order to improve the crashworthiness of vehicle body, it is of great significance to study the energy absorption characteristics of the components. For this reason, specific energy absorption (SEA: the energy absorption per unit mass) of HSP was selected to be the objective function in order to find an optimal design of HSP under impact loading. The explicit finite element analysis (FEA) was used to derive response surface (RS) model of SEA, and a single-objective optimization was performed to get the optimal design. Before the optimization design of HSP, the energy-absorptions of HSP and the honeycomb core (HC) were compared with each other. It was found that HSP could absorb much more impact energy than HC due to the stabilizing effect of the face sheets during the process of crushing.

scholarly journals Dynamic Analysis of Honeycomb Sandwich Beam with Multiple Debonds

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
B. Saraswathy ◽  
R. Ramesh Kumar ◽  
Lalu Mangal
Keyword(s):  
Analytical Solution ◽  
Transient Analysis ◽  
Sandwich Beam ◽  
Beam Theory ◽  
Beam Length ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Fast Fourier Transform Analysis ◽  
Honeycomb Sandwich ◽  
Nonlinear Transient

Analytical formulation for the evaluation of frequency of CFRP sandwich beam with debond, following the split beam theory, generally underestimates the stiffness, as the contact between the honeycomb core and the skin during vibration is not considered in the region of debond. The validation of the present analytical solution for multiple-debond size is established through 3D finite element analysis, wherein geometry of honeycomb core is modeled as it is, with contact element introduced in the debond region. Nonlinear transient analysis is followed by fast Fourier transform analysis to obtain the frequency response functions. Frequencies are obtained for two types of model having single debond and double debond, at different spacing between them, with debond size up to 40% of beam length. The analytical solution is validated for a debond length of 15% of the beam length, and with the presence of two debonds of same size, the reduction in frequency with respect to that of an intact beam is the same as that of a single-debond case, when the debonds are well separated by three times the size of debond. It is also observed that a single long debond can result in significant reduction in the frequencies of the beam than multiple debond of comparable length.

scholarly journals Ballistic Resistance of Honeycomb Sandwich Panels under In-Plane High-Velocity Impact

2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
Chang Qi ◽  
Shu Yang ◽  
Dong Wang ◽  
Li-Jun Yang
Keyword(s):  
Structural Parameters ◽  
Sandwich Panels ◽  
Unit Cell ◽  
Dynamic Responses ◽  
Honeycomb Core ◽  
Ballistic Resistance ◽  
Honeycomb Sandwich ◽  
Aluminum Honeycomb ◽  
Parametric Studies ◽  
Nonmonotonic Effects

The dynamic responses of honeycomb sandwich panels (HSPs) subjected to in-plane projectile impact were studied by means of explicit nonlinear finite element simulations using LS-DYNA. The HSPs consisted of two identical aluminum alloy face-sheets and an aluminum honeycomb core featuring three types of unit cell configurations (regular, rectangular-shaped, and reentrant hexagons). The ballistic resistances of HSPs with the three core configurations were first analyzed. It was found that the HSP with the reentrant auxetic honeycomb core has the best ballistic resistance, due to the negative Poisson’s ratio effect of the core. Parametric studies were then carried out to clarify the influences of both macroscopic (face-sheet and core thicknesses, core relative density) and mesoscopic (unit cell angle and size) parameters on the ballistic responses of the auxetic HSPs. Numerical results show that the perforation resistant capabilities of the auxetic HSPs increase as the values of the macroscopic parameters increase. However, the mesoscopic parameters show nonmonotonic effects on the panels' ballistic capacities. The empirical equations for projectile residual velocities were formulated in terms of impact velocity and the structural parameters. It was also found that the blunter projectiles result in higher ballistic limits of the auxetic HSPs.

Development of Composite Optical Bench Structures on a Satellite Considering Launch and Space Environments

2007 ◽  
Vol 334-335 ◽  
pp. 457-460 ◽  
Author(s):  
Cheol Kim ◽  
Sun Goo Kim ◽  
Yong Yun Kim
Keyword(s):  
Thermal Deformation ◽  
Natural Frequencies ◽  
Compressive Loading ◽  
Sandwich Panels ◽  
Polymeric Composite ◽  
Structural Testing ◽  
Stacking Sequence ◽  
Optical Bench ◽  
Element Analysis ◽  
Space Environments

Satellite structural components must be able to withstand various loading and environments that will experience during integration, tests, transportation, launch, and on-orbit operation. A polymeric composite optical bench that fixes delicate optical payloads such as a camera or a telescope was developed based on static strength, thermal deformation, and vibration. The optical bench consists of composite sandwich panels with and without a hole and composite struts with end fittings. In this paper, the optimum stacking sequence of the composite optical bench was calculated to minimize severe thermal deformations during orbital operation using a genetic algorithm and the finite element analysis. Then, the optimum design is evaluated whether it withstands launch loads (high inertia, vibration, etc.), that are not usually significant compared to orbital thermal loadings, or not. The thermal deformation of sandwich panels was minimized at the stacking sequence of [0/±45]s and that of composite struts was lowest at the angle of [02/90]s. There was no buckling in the compressive loading. By vibration analysis, the natural frequencies of the composite components were much higher than aluminum structures (i.e., sandwich panel: 10.7%; strut: 27.79%) and the stiffness condition expected was satisfied. Then, a composite optical bench was fabricated for tests and all analyses results were verified by structural testing. There were good correlations between two results. To increase the structural stiffness, several Nitinol shape memory alloy wires installed on it and the natural frequencies were measured.

scholarly journals High Temperature Mechanical Properties of a Vented Ti-6Al-4V Honeycomb Sandwich Panel

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3008
Author(s):  
Lei Shang ◽  
Ye Wu ◽  
Yuchao Fang ◽  
Yao Li
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cell Walls ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Honeycomb Core ◽  
Compression Performance ◽  
High Temperature Mechanical Properties ◽  
Honeycomb Sandwich ◽  
The Face

For aerospace applications, honeycomb sandwich panels may have small perforations on the cell walls of the honeycomb core to equilibrate the internal core pressure with external gas pressure, which prevent face-sheet/core debonding due to pressure build-up at high temperature. We propose a new form of perforation on the cell walls of honeycomb sandwich panels to reduce the influence of the perforations on the cell walls on the mechanical properties. In this paper, the high temperature mechanical properties of a new vented Ti-6Al-4V honeycomb sandwich panel were investigated. A vented Ti-6AL-4V honeycomb sandwich panel with 35Ti-35Zr-15Cu-15Ni as the filler alloy was manufactured by high-temperature brazing. The element distribution of the brazed joints was examined by means of SEM (scanning electron microscopy) and EDS (energy-dispersive spectroscopy) analyses. Compared to the interaction between the face-sheets and the brazing filler, the diffusion and reaction between the honeycomb core and the brazing filler were stronger. The flatwise compression and flexural mechanical properties of the vented honeycomb sandwich panels were investigated at 20, 160, 300, and 440 °C, respectively. The flatwise compression strength, elastic modulus, and the flexural strength of the vented honeycomb sandwich panels decreased with the increase of temperature. Moreover, the flexural strength of the L-direction sandwich panels was larger than that of the W-direction sandwich panels at the same temperature. More importantly, the vented honeycomb sandwich panels exhibited good compression performance similar to the unvented honeycomb sandwich panels, and the open holes on the cell walls have no negative effect on the compression performance of the honeycomb sandwich panels in these conditions. The damage morphology observed by SEM revealed that the face-sheets and the brazing zone show ductile and brittle fracture behaviors, respectively.

Compression after impact behavior of titanium honeycomb sandwich structures

2017 ◽  
Vol 20 (5) ◽  
pp. 639-657 ◽  
Author(s):  
Wei Zhao ◽  
Zonghong Xie ◽  
Xiang Li ◽  
Xishan Yue ◽  
Junfeng Sun
Keyword(s):  
Failure Modes ◽  
Sandwich Structures ◽  
Impact Damage ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Failure Strength ◽  
Compressive Failure ◽  
Low Velocity ◽  
Honeycomb Sandwich

Titanium honeycomb sandwich structures are gradually used in several newly developed aircrafts in China. During the manufacturing process and aircraft service life, low-velocity impacts from foreign objects (typically stones, tools and hails, etc.), would quite likely happen and could not be completely avoided. In order to evaluate the influence of low-velocity impact damage on titanium honeycomb sandwich structures, unidirectional in-plane compression tests on both intact and impact damaged sandwich panels were conducted to obtain their failure modes and compressive failure strength. Test results showed that the low-velocity impact damage could cause the change in failure modes and a 9% to 15% decrease in the compressive failure strength. Different impact energy levels showed a limited influence on the compressive failure strength. Numerical analysis was conducted to study the compression after impact behavior of titanium sandwich panels. Parametric finite element models that contained all the geometric and the structural details of honeycomb core cells, as well as the indentation and the crushed core region, were developed in the analysis. The numerical results successfully exhibited the failure process of the intact and impact damaged titanium sandwich panels subjected to unidirectional in-plane compression, similar to what observed in the tests. The predicted compressive failure strength also agreed very well with the test data.

Trial Fabrication of Carbon Fiber-Reinforced Thermoplastic Honeycomb Sandwich Materials

2018 ◽  
Vol 774 ◽  
pp. 25-30
Author(s):  
Hitoshi Takagi ◽  
Kenya Nishimura ◽  
Antonio N. Nakagaito
Keyword(s):  
Carbon Fiber ◽  
Mechanical Performance ◽  
Sandwich Panels ◽  
Fiber Reinforced ◽  
Honeycomb Core ◽  
Honeycomb Sandwich ◽  
Carbon Fiber Reinforced ◽  
Honeycomb Cores ◽  
Flexural Tests ◽  
Sandwich Materials

This paper deals with a new fabrication technique of carbon fiber-reinforced thermoplastic (CFRTP) honeycomb cores and all-CFRTP honeycomb sandwich panels. The CFRTP core was made of plane woven carbon fiber-reinforced polypropylene prepreg sheets. The stacked CFRTP prepreg sheets were periodically hot-pressed at the node locations, and then expanded to form an all-CFRP honeycomb core. The resultant CFRTP honeycomb cores were glued with the same polypropylene-based plain-woven CFRTP skin plates. The mechanical performance of the all-CFRTP honeycomb sandwich panels was evaluated by flexural tests. The experimental results showed the effectiveness of proposed all-CFRTP sandwich panels.

scholarly journals Design and analysis of a light electric vehicle

2021 ◽  
Vol 12 (1) ◽  
pp. 345-360
Author(s):  
Chang-Sheng Lin ◽  
Chang-Chen Yu ◽  
Yue-Hao Ciou ◽  
Yi-Xiu Wu ◽  
Chuan-Hsing Hsu ◽  
...  
Keyword(s):  
Finite Element ◽  
Electric Vehicle ◽  
Load Condition ◽  
Vehicle Body ◽  
Vehicle Design ◽  
Element Analysis ◽  
The Real ◽  
The Stability ◽  
State Relay ◽  
Model Formation

Abstract. This paper discusses a systematic vehicle design process in which light weight is taken as the vehicle design objective, and the designed frame is analyzed in detail. The load condition of a vehicle under different circumstances is calculated according to the distances from the front and rear wheels to the centroid position. The stress on the components in the condition is analyzed by finite element analysis, the steering geometry of the vehicle is analyzed, and the vehicle's turning angle and radius are designed. The displacement of the vehicle under a load is calculated by rigidity analysis to determine the stability of the vehicle in motion. The experimental modal analysis of the real frame and the finite element method are verified mutually for the electric vehicle body-in-white (BIW) manufacturing process to determine the consistency of model formation and the real frame. In terms of the circuit design, we used no-fuse switches and fuses to provide overcurrent protection for the main power supply, and the chip is combined with an optically coupled circuit and current sensor, which is driven by a restriction controller for protection. Moreover, a solid-state relay (SSR) is used for current protection and for controlling the forward/reverse rotation of the motor.

Strength Characteristics and Deformation Behavior of Aluminum Honeycomb Sandwich Plates under Three-Point Bending Loads

2005 ◽  
Vol 297-300 ◽  
pp. 1503-1509
Author(s):  
Hyoung Gu Kim ◽  
Nak Sam Choi
Keyword(s):  
Failure Modes ◽  
Skin Layer ◽  
Strength Characteristics ◽  
Sandwich Plates ◽  
Honeycomb Core ◽  
Three Point Bending ◽  
Honeycomb Sandwich ◽  
Aluminum Honeycomb ◽  
Deformation Behaviors ◽  
Bending Loads

The strength characteristics as well as local deformation behaviors of honeycomb sandwich composite (HSC) structures under three-point bending loads were investigated in consideration of various failure modes such as skin layer yielding, interface-delamination as well as shear deformation and local buckling in the core layer. Various types of aluminum honeycomb core and skin layer were used for this study. Their finite-element simulation was performed to analyze stresses and deformation behaviors of honeycomb sandwich plates. The results were very comparable to the experimental ones. Consequently, thicker skin layer, smaller cell size of honeycomb core and less delamiantion had dominant effects on the improvement in strength and deformation behaviors of honeycomb sandwich plates.

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