scholarly journals The Flexural Fatigue Behavior of Honeycomb Sandwich Composites Following Low Velocity Impacts

2020 ◽  
Vol 10 (20) ◽  
pp. 7262
Author(s):  
Murat Yavuz Solmaz ◽  
Tolga Topkaya
Keyword(s):  
Impact Damage ◽  
Damping Ratio ◽  
Sheet Material ◽  
Low Velocity Impact ◽  
Face Sheet ◽  
Low Velocity ◽  
Velocity Impact ◽  
Flexural Fatigue ◽  
Honeycomb Sandwich ◽  
The Face

This study experimentally investigated the flexural fatigue behaviors of honeycomb sandwich composites subjected to low velocity impact damage by considering the type and thickness of the face sheet material, the cell size and the core height parameters. Carbon-fiber reinforced composite and the aluminum alloy was used as the face sheet material. First, the static strength of undamaged and damaged specimens was determined by three-point bending loads. Secondly, the fatigue behaviors of the damaged and undamaged specimens were determined. Low velocity impact damage decreased the flexural strength and fatigue lives but increased the damping ratio for all specimens. Maximum damping ratio values were observed on specimens with a aluminum face sheet.

Low-velocity impact behaviour of titanium honeycomb sandwich structures

2017 ◽  
Vol 20 (8) ◽  
pp. 1009-1027 ◽  
Author(s):  
Zonghong Xie ◽  
Wei Zhao ◽  
Xinnian Wang ◽  
Jiutao Hang ◽  
Xishan Yue ◽  
...  
Keyword(s):  
Contact Force ◽  
Sandwich Structures ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Honeycomb Sandwich ◽  
The Impact ◽  
Maximum Contact ◽  
Positive Effect

Titanium honeycomb sandwich structures are gradually used in newly developed aircrafts in China. In this study, low-velocity impact tests on the titanium honeycomb sandwich structures were carried out to obtain the impact dynamic response and investigate the typical impact damage modes and parameters including the depths and diameters of the facesheet indentation and the core crushing region. The test results showed that the maximum contact force, the diameter and depth of the indentation had strong positive correlations to the impact energy. Numerical analysis was also conducted to study the low-velocity impact behaviour of the titanium honeycomb sandwich structures by using parametric finite element models that contained all the geometric and the structural details of the titanium honeycomb cores. The numerical results successfully captured the typical low-velocity impact damage modes of the titanium sandwich structures, similar to those observed in the tests. The predicted impact dynamic response also agreed very well with the test data. By using the validated finite element models, a parameter sensitivity study on the effects of the structural parameters on the low-velocity impact damage behaviour of the titanium sandwich structures was conducted. The parametric analysis results showed that the impactor diameter, the facesheet thickness and the core cell wall thickness had positive effect on the maximum contact force, and negative effect on the indentation depth, while the height of the honeycomb core had positive effect on the contact force, but little influence on the indentation depth.

scholarly journals The Low Velocity Impact Response of Foam Core Sandwich Panels with a Shape Memory Alloy Hybrid Face-Sheet

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2076 ◽  
Author(s):  
Hao Li ◽  
Zhenqing Wang ◽  
Zhengwei Yu ◽  
Min Sun ◽  
Yanfei Liu
Keyword(s):  
Impact Damage ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Face Sheet ◽  
Foam Core ◽  
Low Velocity ◽  
Damage Resistance ◽  
Velocity Impact ◽  
Bottom Face ◽  
The Impact

Most foam core sandwich panels are sensitive to the impact load because of the poor toughness of thin composite face-sheets and the low strength of foam core. Superelastic shape memory alloy (SMA) wires have been applied to enhance the impact damage resistance of composite laminates in recent decades. To improve the impact damage resistance of foam core sandwich panels and to protect the foam core, SMA wires were incorporated into the face-sheets of foam core sandwich panels in this work. Eight new types of SMA hybrid sandwich panels were designed, and low-velocity impact tests were carried out at an impact energy of 35 J. The damage morphology of the impacted sandwich panels was identified by visual inspection and scanning electron microscope technology. Results indicate that the impact damage resistance of the SMA hybrid sandwich panels is enhanced. The damage area in the hybrid sandwich panels is greatly reduced and a decrease of 85.63% can be reached in the bottom face-sheet. The maximum contact force has an improvement of 28.15% when the two layers of SMA wires are incorporated into the bottom face-sheet.

Low velocity impact and compression after impact behaviour of polyester pin-reinforced foam filled honeycomb sandwich panels

2021 ◽  
pp. 109963622199818
Author(s):  
RS Jayaram ◽  
VA Nagarajan ◽  
KP Vinod Kumar
Keyword(s):  
Impact Damage ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area ◽  
Compression After Impact ◽  
Honeycomb Sandwich ◽  
Foam Filled ◽  
The Impact

Hybridization of sandwich panels and their different components have drawn huge attention due to the significant improvement in their attributes. Hybrid core of ‘Polyester Pin-reinforced Foam filled Honeycomb Sandwich panels’ (PFHS) were fabricated and compared with unreinforced ‘Foam filled Honeycomb Sandwich panels’ (FHS) in terms of low velocity impact and Compression After Impact (CAI) performance. The impact damage area was calculated by employing MATLAB image processing technique. Incorporating through thickness pins for connecting faces and core is an effectual way to improve interfacial bonding, specific bending stiffness and also imparts out of plane properties for sandwich panels. The low velocity impact tests performed on the sandwich panels revealed that the polyester pin reinforcement in foam filled honeycomb sandwich panel improved the load bearing capacity, total absorbed energy and reduced the impact damage area significantly. In CAI test, debond, wrinkling of face sheet, and buckling of face sheet and core are the major modes of failure. The addition of the pins enhanced the compressive strength for all the impact energy levels.

Effect of Core Thicknesses on Impact Performance of Thermoplastic Honeycomb Core Sandwich Structure under Low-Velocity Impact Loading

2011 ◽  
Vol 471-472 ◽  
pp. 461-465
Author(s):  
Nurashikin Sawal ◽  
Md Akil Hazizan
Keyword(s):  
Impact Force ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Face Sheet ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area ◽  
Impact Performance ◽  
Core Thickness ◽  
The Impact

Low-velocity impact test on sandwich panels composed of aluminum face sheets and thermoplastic honeycomb cores have been performed to characterize the impact performance as a function of core thickness and drop heights. Impact parameters like maximum impact force, impact energy and impact damage area were evaluated and compared. Consequent damages were inspected visually on the impact surface as well as the rear surface. The experimental results found that panels with thicker core exhibited higher impact force than thinner core counterparts, allowing the panel to absorbed more energy. Higher degree of impact damage can be observed at elevated drop heights as most of the damage took the form of local core crushing, face sheet buckling and debonding between the face sheet and core,. Resulting damage area were different according to the core thickness as thicker core prone to absorbed more energy that lead to more damage propagation.

Impact Damage Resistance of Thin-Core Sandwich Structures Subjected to Low-Velocity Impact

2014 ◽  
Vol 684 ◽  
pp. 176-181
Author(s):  
Kai Lun Wang ◽  
Zhi Dong Guan ◽  
Jun Guo ◽  
Zeng Shan Li
Keyword(s):  
Sandwich Structures ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Resistance ◽  
Velocity Impact ◽  
The Core ◽  
The Face ◽  
The Impact ◽  
Impact Damages

This paper aims at evaluating the damage resistance of thin core sandwich structures, composed of aramid paper honeycomb core and carbon/ epoxy laminates face-sheets subjected to low velocity impact. The impact tests are performed using the instrumented impact-testing machine and resulting impact damages are inspected by Ultrasonic C-scan. In order to study the failure process of the core, which is important in the damage of the structures, flatwise compression test was carried out. Four parameters have been analyzed as follows: maximum load, total energy absorbed during impact, impact dent depth, and impact damage area. Nearly all impact force histories of panels have “twin peaks”, but the second peak of the 3mm-core structure is much larger than the first, which is quite different from others, when impact energy reached 5J, which were caused by the thickness of the core. Impact damages of thin-core sandwich structures are mainly delamination in the face-sheet and core crushing at low energy, and fiber breakage at relatively high energy. The damage processes of different groups of structures are essentially different and the impact resistance of the sandwich structure is greatly influenced by the face-sheet and core thickness.

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