Digital Sequence and Virtual Path Construction-Based Impact Imaging Method for Onboard Monitoring of Aerospace Composite Structures

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Yuanqiang Ren ◽  
Lei Qiu ◽  
Shenfang Yuan ◽  
Xiaodong Lin
Keyword(s):  
Composite Structures ◽  
Impact Resistance ◽  
Guided Wave ◽  
Imaging Method ◽  
Virtual Path ◽  
Monitoring Methods ◽  
Accurate Localization ◽  
Impact Monitoring ◽  
Hardware System ◽  
The Impact

Abstract Because of the rapidly growing use and poor impact resistance of composite materials, impact monitoring of composite structures has become more and more important, especially for aerospace engineering applications. Among the existing impact monitoring methods, piezoelectric transducer (PZT) network and guided wave-based imaging method has proved to be an effective structural health monitoring (SHM) technology. However, the pursuit of accurate localization of ordinary impact imaging methods comes at a cost, the high requirement for the SHM hardware system making these methods inapplicable for onboard impact monitoring. In order to realize accurate impact monitoring of aerospace composite structures onboard, this paper proposes a digital sequence and virtual path construction-based impact imaging method, which is simple enough to work in a digital impact monitor with a greatly simplified hardware system. The monitor is used to convert the impact response signals of PZTs into digital sequences, based on which the method first recognizes the impact occurring sub-region. Then, the virtual pitch–catch paths of the recognized sub-region are innovatively defined and constructed to estimate the impact-induced influence on these paths so that the path-synthesis imaging algorithm-based impact imaging can be performed with little computation cost. To verify the feasibility and effectiveness of the proposed method, a total of 90 impacts are applied on a composite unmanned aerial vehicle (UAV) wing, and experimental results show the good performance of accurate impact imaging and localization.

scholarly journals Effect of Thermal Ageing on the Impact Damage Resistance and Tolerance of Carbon-Fibre-Reinforced Epoxy Laminates

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 160 ◽  
Author(s):  
Irene García-Moreno ◽  
Miguel Caminero ◽  
Gloria Rodríguez ◽  
Juan López-Cela
Keyword(s):  
Carbon Fibre ◽  
Residual Strength ◽  
Composite Structures ◽  
Impact Resistance ◽  
Thermal Ageing ◽  
Low Velocity Impact ◽  
Impact Tests ◽  
Compression After Impact ◽  
Structural Applications ◽  
The Impact

Composite structures are particularly vulnerable to impact, which drastically reduces their residual strength, in particular, at high temperatures. The glass-transition temperature (Tg) of a polymer is a critical factor that can modify the mechanical properties of the material, affecting its density, hardness and rigidity. In this work, the influence of thermal ageing on the low-velocity impact resistance and tolerance of composites is investigated by means of compression after impact (CAI) tests. Carbon-fibre-reinforced polymer (CFRP) laminates with a Tg of 195 °C were manufactured and subjected to thermal ageing treatments at 190 and 210 °C for 10 and 20 days. Drop-weight impact tests were carried out to determine the impact response of the different composite laminates. Compression after impact tests were performed in a non-standard CAI device in order to obtain the compression residual strength. Ultrasonic C-scanning of impacted samples were examined to assess the failure mechanisms of the different configurations as a function of temperature. It was observed that damage tolerance decreases as temperature increases. Nevertheless, a post-curing process was found at temperatures below the Tg that enhances the adhesion between matrix and fibres and improves the impact resistance. Finally, the results obtained demonstrate that temperature can cause significant changes to the impact behaviour of composites and must be taken to account when designing for structural applications.

scholarly journals Modeling Analysis of Guided Ultrasonic Waves in Composite Plates with Impact Damage

2018 ◽  
Vol 7 (4.26) ◽  
pp. 175
Author(s):  
Noorfaten Asyikin Ibrahim ◽  
Bibi Intan Suraya Murat
Keyword(s):  
Composite Structures ◽  
Impact Damage ◽  
Composite Plates ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Fe Model ◽  
Element Analysis ◽  
Damage Area ◽  
Guided Ultrasonic Waves ◽  
The Impact

This paper investigates the propagation of guided ultrasonic waves and the interaction with impact damage in composite plates using a full three-dimensional Finite Element analysis. Impact damage in the composite plate was modeled as rectangular- and T-shaped delaminations. In order to provide guidelines for extending the modeling of realistic multimode impact damage, the impact damage was modeled as a combination of the delamination and reduced materials properties. The information obtained from these methods was compared to the experimental results around the damage area for a validation. There was a reasonable similarity between the experimental and FE results. The FE simulations can effectively model the scattering characteristics of the A0 mode wave propagation in anisotropic composite plates. This suggests that the simplified and easy-to-implement FE model could be used to represent the complex impact damage in composite plates. This could be useful for the improvement of the FE modeling and performance of guided wave methods for the in-situ NDE of large composite structures. 

scholarly journals Guided Waves for Damage Detection in Complex Composite Structures: The Influence of Omega Stringer and Different Reference Damage Size

2020 ◽  
Vol 10 (9) ◽  
pp. 3068
Author(s):  
Jochen Moll ◽  
Christian Kexel ◽  
Jens Kathol ◽  
Claus-Peter Fritzen ◽  
Maria Moix-Bonet ◽  
...  
Keyword(s):  
Composite Structures ◽  
Guided Waves ◽  
Fiber Composite ◽  
Composite Plates ◽  
Guided Wave ◽  
Probability Of Detection ◽  
Carbon Fiber Composite ◽  
Technical Validation ◽  
Pod Analysis ◽  
The Impact

The third dataset dedicated to the Open Guided Waves platform aims at carbon fiber composite plates with an additional omega stringer at constant temperature conditions. The two structures used in this work are representative for real aircraft components. Comprehensive measurements were recorded in order to study (I) the impact of the omega stringer on guided wave propagation, and (II) elliptical reference damages of different sizes located at three separate positions on the structure. Measurements were recorded for narrowband excitation (5-cycle toneburst with varying carrier frequencies) and broadband excitation (using chirp waveforms). The paper presents the results of a technical validation including numerical modelling, and enables further research, for example related to probability of detection (POD) analysis.

Impact response of nanoparticle reinforced 3D woven spacer/epoxy composites at cryogenic temperatures

2021 ◽  
pp. 002199832110370
Author(s):  
Ferhat Yıldırım ◽  
Ahmet Caner Tatar ◽  
Volkan Eskizeybek ◽  
Ahmet Avcı ◽  
Mustafa Aydın
Keyword(s):  
Composite Structures ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Woven Composites ◽  
Cryogenic Temperatures ◽  
Low Velocity ◽  
Impact Performance ◽  
Fiber Reinforced Polymer Composites ◽  
3D Woven Composites ◽  
The Impact

Fiber-reinforced polymer composites serving in harsh conditions must maintain their performance during their entire service. The cryogenic impact is one of the most unpredictable loading types, leading to catastrophic failures of composite structures. This study aims to examine the low-velocity impact (LVI) performance of 3D woven spacer glass-epoxy composite experimentally under cryogenic temperatures. LVI tests were conducted under various temperatures ranging from room temperature (RT) to −196°C. Experimental results reveal that the 3D composites gradually absorbed higher impact energies with decreasing temperature. Besides, the effect of multi-walled carbon nanotube and SiO2 nanofiller reinforcements of the matrix on the impact performance and the damage characteristics were further assessed. Nanofiller modification enhanced the impact resistance up to 30%, especially at RT. However, the nanofiller efficiency declined with decreasing temperature. The apparent damages were visually examined by scanning electron microscopy to address the damage formation. Significant outcomes have been achieved with the nanofiller modification regarding the new usage areas of 3D woven composites.

Improvement of Biocomposite Performance under Low-Velocity Impact Test - A Review

2021 ◽  
Vol 893 ◽  
pp. 67-74
Author(s):  
Usha Kiran Sanivada ◽  
Gonzalo Mármol ◽  
Francisco P. Brito ◽  
Raul Fangueiro
Keyword(s):  
Composite Structures ◽  
Impact Test ◽  
Impact Resistance ◽  
Vital Role ◽  
Low Velocity Impact ◽  
Efficient Design ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Tests ◽  
The Impact

The study of the impact energy and the composite behaviour plays a vital role in the efficient design of composite structures. Among the various categories of impact tests, it is essential to study low-velocity impact tests as the damage generated due to these loads is often not visible to the naked eye. The internal damages can reduce the strength of the composites and hence the impact behaviour must be addressed specifically for improving their applications in the transport industry. The main aim of this paper is to provide a comprehensive review of the work focusing on the assessment of biocomposites performance under low impact velocity, the different deformations, and damage mechanisms, as well the methods to improve the impact resistance.

Research on Dynamic Cumulative Damage Effect of Metal Rubber and Stress Wave Propagation Characteristics of Layered Composite Structure

2021 ◽  
Vol 13 (5) ◽  
pp. 981-990
Author(s):  
Youchun Zou ◽  
Chao Xiong ◽  
Junhui Yin ◽  
Kaibo Cui ◽  
Huiyong Deng ◽  
...  
Keyword(s):  
Stress Wave ◽  
Composite Structure ◽  
Composite Structures ◽  
Impact Resistance ◽  
Layered Composite ◽  
Damage Effect ◽  
Stress Wave Propagation ◽  
Metal Rubber ◽  
Layered Composite Structures ◽  
The Impact

The development of protective materials and structures is of great significance for improving the impact resistance, penetration resistance and spalling resistance of military equipment. At present, the layered composite structure has been widely used due to its good protective performance. In this paper, a special elastic porous material-metal rubber (MR) with excellent cushioning and damping properties was used to prepare high-performance layered composite structures. To begin with, the dynamic mechanical response and the dynamic cumulative damage effect of MR were studied through Split-Hopkinson Pressure Bar (SHPB) tests. Then, the failure form and stress wave propagation characteristics of the layered composite structures were investigated through SHPB tests and finite element method. The results show that repeated impacts can enhance the compactness of MR, thereby increasing the ultimate bearing capacity and energy absorption capacity, which is beneficial for MR to resist repeated impacts. The MR in composite structures can reduce ceramic damage, attenuate stress wave and smooth stress distribution. The titanium alloy on the back of the ceramic will aggravate the damage of the ceramic, and ultra-high molecular weight polyethylene on the back of the ceramic provides cushioning for the ceramic. Therefore, the impact resistance of the composite structure can be improved by adding MR and the reasonable arrangement of materials, and the SiC/UHMWPE/MR/TC4 composite structure has relatively reasonable stress distribution and better protection performance.

Real-Time Impact Monitoring of Composites for Ship Applications

2015 ◽  
Vol 813 ◽  
pp. 72-77 ◽  
Author(s):  
Ming Yu Lu ◽  
Hai Nan Yang ◽  
Xin Lin Qing ◽  
Zhong Qing Su ◽  
Li Min Zhou
Keyword(s):  
Real Time ◽  
Lead Zirconate Titanate ◽  
Power Distribution ◽  
Composite Structures ◽  
Impact Damage ◽  
Aviation Industry ◽  
Load History ◽  
Processing Scheme ◽  
Impact Monitoring ◽  
The Impact

Composites are getting more and more attention in the usage of major structures on ships owing to many advantages such as high specific strength and rigidity. However, composites are sensitive to impact, which indicates that the load-carrying capacity and stability of composite structures will decrease dramatically even for an invisible impact damage. Hence, a real-time impact monitoring system which has already been applied in aviation industry is important for reliability of ships, which inevitably encounter impacts during their lifetime due to different sources. This paper deals with the realization of an operational processing scheme to monitor the impact on composite structures, and estimate the impact location and load history by power distribution approach and system identification method. A PZT (piezoelectric lead zirconate titanate) sensor network was designed and employed to collect sensing signals for monitoring the impact. In the monitoring process, stress wave signals caused by impact were captured, and used to determine the impacted location and load history. Results demonstrate that the proposed method can be successfully applied in identifying the location and load history of impact on composite structures. The impact identification approach is of great significance for marine applications.

Effect of Strength Parameters and the Structure of Steel Cord Conveyor Belts on Belt Puncture Resistance

2014 ◽  
Vol 683 ◽  
pp. 119-124 ◽  
Author(s):  
Henryk Komander ◽  
Miroslaw Bajda ◽  
Grzegorz Komander ◽  
Gabriela Paszkowska
Keyword(s):  
Research Work ◽  
Impact Resistance ◽  
Conveyor Belt ◽  
Laboratory Research ◽  
Monitoring Methods ◽  
Strength Parameters ◽  
Puncture Resistance ◽  
Conveyor Belts ◽  
Steel Cord ◽  
The Impact

Conveyor belts transporting rock material are getting worn out mainly as a consequence of punctures and cuts caused by impacts of rock lumps in the belt loading zone. To enhance the operational durability of conveyor belts multidirectional actions intended to lower the dynamic load of belts, to increase the belt impact resistance and to monitor the belt condition are undertaken. Some significant improvements can be achieved by decreasing the material fall height, by implementation of transported material slides in transfer chutes and shock absorbing belt supports as well as by reducing rock lump sizes. To avoid extensive wear belt monitoring methods are being developed, so that belt defect numbers, sizes, and locations can be identified [1]. Implementation of monitoring prevents sudden belt tear and enables rational belt management by repairing and regenerating belts in the optimum time. Laboratory research programmes aim at identifying the relation of the dynamic stress and the belt fatigue strength [2,3]. Investigations of the effect of strength parameters and the structure of steel cord conveyor belts on their puncture resistance are carried out since many years [4,5,6,7]. High puncture resistance of a conveyor belt is one of the main assessment criteria of its operational durability. Research work on the impact of belt top cover thickness, cover rubber properties and type of belt crosswise reinforcements on the belt puncture resistance was undertaken in the Laboratory of Belt Transportation (LBT) of Wroclaw University of Technology [8].

Kernel Feature Space Based Low Velocity Impact Monitoring

2012 ◽  
Author(s):  
Yingtao Liu ◽  
Masoud Yekani Fard ◽  
Aditi Chattopadhyay
Keyword(s):  
Composite Structures ◽  
Impact Damage ◽  
Damage Index ◽  
Low Velocity Impact ◽  
Kernel Principal Component Analysis ◽  
Monitoring Methods ◽  
Low Velocity ◽  
Velocity Impact ◽  
Statistical Feature ◽  
The Impact

Impact damage has been identified as a critical form of defect that constantly threatens the reliability of composite structures, such as those used in aircrafts and naval vessels. Low energy impacts can introduce barely visible damage and cause structural degradation. Therefore, efficient structural health monitoring methods, which can accurately detect, quantify, and localize impact damage in complex composite structures, are required. In this paper a novel damage detection methodology is demonstrated for monitoring and quantifying the impact damage propagation. Statistical feature matrices, composed of features extracted from the time and frequency domains, are developed. Kernel Principal Component Analysis (KPCA) is used to compress and classify the statistical feature matrices. Compared with traditional PCA algorithm, KPCA method shows better feature clustering and damage quantification capabilities. A new damage index, formulated using Mahalanobis distance, is defined to quantify impact damage. The developed methodology has been validated using low velocity impact experiments with a sandwich composite wing.

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