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.

Nondestructive Methods for the Damage Assessment of Cylindrically Curved Composite Laminates Subjected to Low-Velocity Impact

2002 ◽  
Author(s):  
Oh-Yang Kwon ◽  
Jung-Kyu Jun ◽  
Yuris A. Dzenis
Keyword(s):  
Composite Laminates ◽  
Damage Assessment ◽  
Impact Damage ◽  
Acoustic Microscopy ◽  
Low Velocity Impact ◽  
Layer By Layer ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact ◽  
Maximum Contact

Curved composite laminates appeared to be more vulnerable than flat ones to rapid transverse loading. Damage induced by low-velocity impact on the cylindrically curved composite laminates has been experimentally investigated. Graphite/epoxy shells with the radius of curvatures of 150 mm showed quite different impact response and damage behavior from that of flat laminate. Under the same impact energy level, the maximum contact force varied with the radius of curvatures, which is directly related to the impact damage. Delamination was distributed rather evenly at each interface along the thickness direction of curved laminates on the contrary to the case of flat laminates, where delamination is typically concentrated at the interfaces away from the impact point. Due to the presence of curvature, the acoustic microscopy could not be directly applied to the layer-by-layer assessment of delamination damage. As an alternative, the penetrant-enhanced X-radiography (PEXR) was introduced and the results from PEXR were compared with those from destructive examination of the cross-section by scanning electron microscopy.

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.

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.

Low Velocity Impact on Fiber Reinforced Geocomposites

2016 ◽  
Vol 827 ◽  
pp. 145-148 ◽  
Author(s):  
Sneha Samal ◽  
David Reichmann ◽  
Iva Petrikova ◽  
Bohdana Marvalova
Keyword(s):  
Impact Damage ◽  
Acoustic Vibration ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Behaviour ◽  
Reinforced Composite ◽  
Before And After ◽  
Two Parameters ◽  
The Impact

Low velocity impact strength of the fabric reinforced geocomposite has investigated in this article. Various fabrics such as carbon and E-glass were considered for reinforcement in geopolymer matrix. The primary two parameters such as low velocity, impact damage modes are explained on the E-glass and carbon based fabric geocomposite. The onset mode of damage to failure mode is examined through C-scan analysis. The quality of the composite is observed using c-scan with acoustic vibration mode of sensor before and after impact test. Then the effect of fabric and matrix on the impact behaviour is discussed. Residual strength of the composite is measured to determine post impact behaviour. It has been observed that resistance properties of E-glass reinforced composite is better than carbon fabric reinforced composite.

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.

scholarly journals Assessment of low-velocity impact damage in composites by the measure of second-harmonic guided waves with the phase-reversal approach

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041988107 ◽  
Author(s):  
Weibin Li ◽  
Chang Jiang ◽  
Xinlin Qing ◽  
Liangbing Liu ◽  
Mingxi Deng
Keyword(s):  
Guided Waves ◽  
Second Harmonic ◽  
Impact Damage ◽  
Guided Wave ◽  
Second Order ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Phase Reversal ◽  
The Impact

Structural strength and integrity of composites can be considerably affected by the low-velocity impact damage due to the unique characteristics of composites, such as layering bonded by adhesive and the weakness to impact. For such damage, there is an urgent need to develop advanced nondestructive testing approaches. Despite the fact that the second harmonics could provide information sensitive to the structural health condition, the diminutive amplitude of the measured second-order harmonic guided wave still limits the applications of the second-harmonic generation–based nonlinear guided wave approach. Herein, laminated composites suffered from low-velocity impact are characterized by use of nonlinear guided waves. An enhancement in the signal-to-noise ratio for the measure of second harmonics is achieved by a phase-reversal method. Results obtained indicate a monotonic correlation between the impact-induced damage in composites and the relative acoustic nonlinear indicator of guided waves. The experimental finding in this study shows that the measure of second-order harmonic guided waves with a phase-reversal method can be a promising indicator to impact damage rendering in an improved and reliable manner.

Low-Velocity Impact Characteristics of Carbon Fiber Composites Lattice Core Sandwich Structures

2009 ◽  
Vol 79-82 ◽  
pp. 127-130 ◽  
Author(s):  
Shi Xun Wang ◽  
Lin Zhi Wu ◽  
Li Ma
Keyword(s):  
Carbon Fiber ◽  
Sandwich Structures ◽  
Impact Damage ◽  
Composite Plates ◽  
Fiber Composites ◽  
Low Velocity Impact ◽  
Carbon Fiber Composites ◽  
Low Velocity ◽  
Velocity Impact ◽  
Numerical Predictions

Since composite sandwich structures are susceptible to low-velocity impact damage, a thorough characterization of the loading and damage process during impact is important. In the present paper, the low-velocity impact response of carbon fiber composites lattice structures are investigated by experimental and numerical methods. Impact tests on composite plates are performed using an instrumented drop-weight machine (Instron 9250HV) and a new damage mode is observed. A three-dimensional finite element model is built by ABAQUS/Explicit and user subroutine (VUMAT) to predict the peak loading and simulate the complicated damage problem. It can be found that numerical predictions coincide well with experimental results.

Analysis on Low Velocity Impact Damage and Compressive Residual Strength of Composite Laminates

2014 ◽  
Vol 566 ◽  
pp. 463-467
Author(s):  
Pu Xue ◽  
H.H. Chen ◽  
W. Guo
Keyword(s):  
Experimental Data ◽  
Residual Strength ◽  
Composite Laminates ◽  
Damage Mechanics ◽  
Impact Damage ◽  
Numerical Results ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

This paper studies the impact damage under low velocity impact for composite laminates based on a nonlinear progressive damage model. Damage evolution is described by the framework of the continuum damage mechanics. The real impact damage status of composite laminates has been used to analyze the residual compressive strength instead of assumptions on damage area after impact. The validity of the methodologies has been demonstrated by comparing the numerical results with the experimental data available in literature. The delamination area has an error of 11.3%. The errors of residual strength and compressive displacement are 8.9% and 15%, which indicate that the numerical results matched well with the experimental data.

Impact Damage and Strength Reduction Behavior of Honeycomb Sandwich Structure Subjected to Low Velocity Impact

2006 ◽  
Vol 306-308 ◽  
pp. 279-284
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim
Keyword(s):  
Sandwich Structure ◽  
Impact Damage ◽  
Testing Machine ◽  
Strength Reduction ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Reduction Behavior ◽  
Velocity Impact ◽  
The Impact

The goals of the paper are to identify the impact damage and strength reduction behavior of sandwich structure, composed of carbon/epoxy laminates skin and Nomex core with two kinds of thickness (10 and 20mm). For these, low velocity impact tests were conducted using the instrumented impact-testing machine and damages are inspected by SAM. And then, subsequent static tests are conducted under flexural loading to identify the strength reduction behavior of the impacted sandwich structures. The impact damages are mainly delamination in carbon/epoxy skin and their behavior is mostly independent of core thickness. Also, their energy absorbing behavior is identified through calculating the energy absorbed by impact damage. Finally, the strength reduction behavior is evaluated through Caprino’s model, which was proposed on the unidirectional laminates.

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