An Alternative Mechanical Peel Testing Method for Composite Fiberglass Foam Core Sandwiches

1999 ◽  
Author(s):  
John L. Zych ◽  
Scott A. Adamick ◽  
Daniel K. Jones ◽  
Dru M. Wilson ◽  
Wayne A. Boyer
Keyword(s):  
Composite Structures ◽  
Peel Strength ◽  
Foam Core ◽  
Destructive Testing ◽  
Benchmark Data ◽  
Testing Method ◽  
Peel Testing ◽  
Novel Approach ◽  
Wide Range ◽  
Composite Designs

Abstract Nondestructive and destructive testing are vital in the composite material industry to determine the mechanical properties of different designs. This paper presents a novel approach to measuring the mechanical peel strength that may be used for a variety of fiberglass foam core sandwiches. The objective of this study was to develop a testing method that was simple and easily reproduced in other laboratories. The goal was to measure the mechanical peel strength using a device that may be used for a variety of sample sizes and materials. An additional goal was to provide benchmark data on the mechanical peel strength of two particular composite designs. The new testing method may have applications to a wide range of composite structures, and it may eventually lead to a new ASTM standard.

scholarly journals Piezoelectric Impedance-Based Non-Destructive Testing Method for Possible Identification of Composite Debonding Depth

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 621 ◽  
Author(s):  
Wongi S. Na ◽  
Jongdae Baek
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Structural Integrity ◽  
Structural Safety ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Electromechanical Impedance ◽  
Testing Method ◽  
Piezoelectric Impedance ◽  
Non Destructive

Detecting the depth and size of debonding in composite structures is essential for assessing structural safety as it can weaken the structure possibly leading to a failure. As composite materials are used in various fields up to date including aircrafts and bridges, inspections are carried out to maintain structural integrity. Although many inspection methods exist for detection damage of composites, most of the techniques require trained experts or a large equipment that can be time consuming. In this study, the possibility of using the piezoelectric material-based non-destructive method known as the electromechanical impedance (EMI) technique is used to identify the depth of debonding damage of glass epoxy laminates. Laminates with various thicknesses were prepared and tested to seek for the possibility of using the EMI technique for identifying the depth of debonding. Results show promising outcome for bringing the EMI technique a step closer for commercialization.

Novel quantitative non-destructive testing method for composite structures

1998 ◽  
Vol 30 (3-4) ◽  
pp. 299-304 ◽  
Author(s):  
Jin-long Chen ◽  
Yu-wen Qin ◽  
Hong-wei Ji ◽  
Xin-hua Ji
Keyword(s):  
Composite Structures ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Method ◽  
Non Destructive

Non-Destructive Testing of Thermoplastic Carbon Composite Structures

2020 ◽  
Vol 2020 (1) ◽  
pp. 34-52
Author(s):  
Rafał Szymański
Keyword(s):  
Composite Structures ◽  
Ultrasonic Method ◽  
Composite Panel ◽  
Aviation Industry ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Pulse Technique ◽  
Thermoplastic Matrix ◽  
The Subject ◽  
Non Destructive

AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.

scholarly journals Responsive and Personalized Web Layouts with Integer Programming

2021 ◽  
Vol 5 (EICS) ◽  
pp. 1-23
Author(s):  
Markku Laine ◽  
Yu Zhang ◽  
Simo Santala ◽  
Jussi P. P. Jokinen ◽  
Antti Oulasvirta
Keyword(s):  
Integer Programming ◽  
Web Design ◽  
Web Pages ◽  
Web Page Design ◽  
Automated Generation ◽  
Novel Approach ◽  
Wide Range ◽  
Responsive Design ◽  
Responsive Web Design ◽  
Page Design

Over the past decade, responsive web design (RWD) has become the de facto standard for adapting web pages to a wide range of devices used for browsing. While RWD has improved the usability of web pages, it is not without drawbacks and limitations: designers and developers must manually design the web layouts for multiple screen sizes and implement associated adaptation rules, and its "one responsive design fits all" approach lacks support for personalization. This paper presents a novel approach for automated generation of responsive and personalized web layouts. Given an existing web page design and preferences related to design objectives, our integer programming -based optimizer generates a consistent set of web designs. Where relevant data is available, these can be further automatically personalized for the user and browsing device. The paper includes presentation of techniques for runtime adaptation of the designs generated into a fully responsive grid layout for web browsing. Results from our ratings-based online studies with end users (N = 86) and designers (N = 64) show that the proposed approach can automatically create high-quality responsive web layouts for a variety of real-world websites.

scholarly journals Defects and uncertainties of adhesively bonded composite joints

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Sadik Omairey ◽  
Nithin Jayasree ◽  
Mihalis Kazilas
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Production Efficiency ◽  
Adhesive Bonding ◽  
Detection Methods ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Wide Range ◽  
Bonded Composite

AbstractThe increasing use of fibre reinforced polymer composite materials in a wide range of applications increases the use of similar and dissimilar joints. Traditional joining methods such as welding, mechanical fastening and riveting are challenging in composites due to their material properties, heterogeneous nature, and layup configuration. Adhesive bonding allows flexibility in materials selection and offers improved production efficiency from product design and manufacture to final assembly, enabling cost reduction. However, the performance of adhesively bonded composite structures cannot be fully verified by inspection and testing due to the unforeseen nature of defects and manufacturing uncertainties presented in this joining method. These uncertainties can manifest as kissing bonds, porosity and voids in the adhesive. As a result, the use of adhesively bonded joints is often constrained by conservative certification requirements, limiting the potential of composite materials in weight reduction, cost-saving, and performance. There is a need to identify these uncertainties and understand their effect when designing these adhesively bonded joints. This article aims to report and categorise these uncertainties, offering the reader a reliable and inclusive source to conduct further research, such as the development of probabilistic reliability-based design optimisation, sensitivity analysis, defect detection methods and process development.

scholarly journals Density Guarantee on Finding Multiple Subgraphs and Subtensors

2021 ◽  
Vol 15 (5) ◽  
pp. 1-32
Author(s):  
Quang-huy Duong ◽  
Heri Ramampiaro ◽  
Kjetil Nørvåg ◽  
Thu-lan Dam
Keyword(s):  
Lower Bound ◽  
State Of The Art ◽  
The State ◽  
The Other ◽  
Exact Methods ◽  
Practical Solution ◽  
Novel Approach ◽  
Wide Range ◽  
Real World Datasets ◽  
Tensor Data

Dense subregion (subgraph & subtensor) detection is a well-studied area, with a wide range of applications, and numerous efficient approaches and algorithms have been proposed. Approximation approaches are commonly used for detecting dense subregions due to the complexity of the exact methods. Existing algorithms are generally efficient for dense subtensor and subgraph detection, and can perform well in many applications. However, most of the existing works utilize the state-or-the-art greedy 2-approximation algorithm to capably provide solutions with a loose theoretical density guarantee. The main drawback of most of these algorithms is that they can estimate only one subtensor, or subgraph, at a time, with a low guarantee on its density. While some methods can, on the other hand, estimate multiple subtensors, they can give a guarantee on the density with respect to the input tensor for the first estimated subsensor only. We address these drawbacks by providing both theoretical and practical solution for estimating multiple dense subtensors in tensor data and giving a higher lower bound of the density. In particular, we guarantee and prove a higher bound of the lower-bound density of the estimated subgraph and subtensors. We also propose a novel approach to show that there are multiple dense subtensors with a guarantee on its density that is greater than the lower bound used in the state-of-the-art algorithms. We evaluate our approach with extensive experiments on several real-world datasets, which demonstrates its efficiency and feasibility.

scholarly journals Towards Reduced CNNs for De-Noising Phase Images Corrupted with Speckle Noise

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 255
Author(s):  
Marie Tahon ◽  
Silvio Montresor ◽  
Pascal Picart
Keyword(s):  
Phase Error ◽  
Speckle Noise ◽  
Experimental Conditions ◽  
Benchmark Data ◽  
Wide Range ◽  
Phase Images ◽  
Different Depths ◽  
Phase Data ◽  
Do So

Digital holography is a very efficient technique for 3D imaging and the characterization of changes at the surfaces of objects. However, during the process of holographic interferometry, the reconstructed phase images suffer from speckle noise. In this paper, de-noising is addressed with phase images corrupted with speckle noise. To do so, DnCNN residual networks with different depths were built and trained with various holographic noisy phase data. The possibility of using a network pre-trained on natural images with Gaussian noise is also investigated. All models are evaluated in terms of phase error with HOLODEEP benchmark data and with three unseen images corresponding to different experimental conditions. The best results are obtained using a network with only four convolutional blocks and trained with a wide range of noisy phase patterns.

scholarly journals An Advanced Educational Tool for Digital Forensic Engineering

2016 ◽  
Vol 11 (03) ◽  
pp. 15 ◽  
Author(s):  
Primož Cigoj ◽  
Borka Jerman Blažič
Keyword(s):  
Digital Forensics ◽  
Real Life ◽  
University Education ◽  
Educational Tool ◽  
Digital Tool ◽  
College And University ◽  
Novel Approach ◽  
Wide Range ◽  
E Learning ◽  
Forensic Engineering

This paper presents a novel approach to education in the area of digital forensics based on a multi-platform cloud-computer infrastructure and an innovative computer based tool. The tool is installed and available through the cloud-based infrastructure of the Dynamic Forensic Education Alliance. Cloud computing provides an efficient mechanism for a wide range of services that offer real-life environments for teaching and training cybersecurity and digital forensics. The cloud-based infrastructure, the virtualized environment and the developed educational tool enable the construction of a dynamic e-learning environment making the training very close to reality and to real-life situations. The paper presents the Dynamic Forensic Digital tool named EduFors and describes the different levels of college and university education where the tool is introduced and used in the training of future investigators of cybercrime events.

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