scholarly journals Analysis of Surface Defects in Composites Using Digital Image Correlation and Acoustic Emission

2018 ◽  
Vol 66 (5) ◽  
pp. 1217-1224
Author(s):  
Jaroslav Začal ◽  
Petr Dostál ◽  
Jakub Rozlivka ◽  
Martin Brabec
Keyword(s):  
Acoustic Emission ◽  
Composite Material ◽  
Composite Materials ◽  
Digital Image ◽  
Tensile Loading ◽  
Carbon Composite ◽  
Image Correlation ◽  
Damage Diagnostics ◽  
Carbon Composite Materials ◽  
Early Damage

This work employs the acoustic emission (AE) method for material state monitoring. AE presents a non‑destructive evaluation technique, which could be used for detection of microstructural changes in composite material. Work describes the process of acquisition of AE in tensile loading of carbon composite materials. In course of tensile stress, the composite was monitored with optical method, applying principles of digital image correction (DIC). Optical stereovision method enables calculation of field shift and field of proportional deformation at composite surface. The objective is analysis of damage in carbon composite materials and employ the methodology of AE signal processing for facilitation of early damage diagnostics and prediction of structural failure. For this purpose, the experimental setup was designed to obtain results from 50 nominally identical composite samples in tensile loading test. Force load applied on samples was synchronically recorded along with AE and image data. Experimental data were subsequently analysed in a way enabling the description of typical phenomena in course of every measurement. Results show that observation of AE sources could be employed in facilitation of early damage diagnostics and establishment of failure prognosis. It is about internal changes in composite material.

Cluster analysis of acoustic emission signals and tensile properties of carbon/glass fiber–reinforced hybrid composites

2019 ◽  
Vol 18 (5-6) ◽  
pp. 1686-1697 ◽  
Author(s):  
Wen-zheng Zhao ◽  
Wei Zhou
Keyword(s):  
Acoustic Emission ◽  
Digital Image Correlation ◽  
Glass Fiber ◽  
Digital Image ◽  
Hybrid Composites ◽  
Correlation Method ◽  
Tensile Loading ◽  
Image Correlation ◽  
Matrix Cracking ◽  
Woven Composites

Understanding the damage and failure of carbon/glass epoxy hybrid woven composites under tensile loading based on acoustic emission signals is a challenging task in their practical uses. In this study, an approach based on fuzzy c-means algorithm is proposed to process the acoustic emission signals from tensile loading of composites monitored by combining acoustic emission technology and digital image correlation method. The results show that the acoustic emission signals from tensile loading can be divided into three clusters. The three clusters correspond to three kinds of damage modes including matrix cracking, fiber/matrix debonding, delamination, and fiber breakage. By comparing the acoustic characteristics of these classes, a correlation procedure between the clusters and the damage mechanisms observed is proposed. Meanwhile, it can be found that debonding and fiber break signals for glass fiber correspond to a lower frequency range than that for carbon fiber. Moreover, the method combining acoustic emission and digital image correlation can effectively monitor the damage process of the specimen both on the inside and outside, which can provide a reference for the health monitoring of composite structure.

scholarly journals Carbon Fiber Composite Materials in Modern Day Automotive Production Lines: A Case Study

2013 ◽  
Author(s):  
Håkan Petersson ◽  
Damien Motte ◽  
Robert Bjärnemo
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Automotive Industry ◽  
Material Properties ◽  
Fiber Composite ◽  
Stable Process ◽  
Carbon Composite ◽  
Production Equipment ◽  
Production Lines ◽  
Carbon Composite Materials

New and innovative production equipment can be developed by introducing lightweight materials in modern day automotive industry production lines. The properties of these new materials are expected to result in improved ergonomics, energy savings, increased flexibility and more robust equipment, which in the end will result in enhanced productivity. Carbon composite materials are one such alternative that has excellent material properties. These properties are well documented, and the market for carbon composite materials is growing in many areas such as commercial aircrafts, sporting goods and wind turbines. However, when studying the use of carbon composite materials for production equipment in the automotive industry, it was found that there were few, if any, such examples. This paper focuses on innovative ways of making carbon composite materials available for designing automotive industry production equipment by introducing a design and material concept that combines flexibility, relatively low costs and high functionality. By reducing the weight by 60%, it was obvious that the operators were very positive to the new design. But just as important as the improvement of the ergonomic feature, the combination of low weight and material properties resulted in a more robust design and a more stable process of operation. The two main designs (two versions of the steel-based design were constructed) were developed sequentially, making it difficult to compare development costs since knowledge migrated from one project to the next. In this study, the gripper was manufactured in both carbon composite material and steel. The different designs were compared with reference to design costs, functionality, robustness, product costs and ergonomics. The study clearly shows that the composite material represents a favorable alternative to conventional materials, as the system combines superior properties without significantly increasing the cost of the equipment. This paper describes the approach in detail.

A novel method to prepare a nanotubes@mesoporous carbon composite material based on waste biomass and its electrochemical performance

2017 ◽  
Vol 5 (8) ◽  
pp. 3875-3887 ◽  
Author(s):  
Huanxin Li ◽  
Yi Gong ◽  
Chaopeng Fu ◽  
Haihui Zhou ◽  
Wenji Yang ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Mesoporous Carbon ◽  
Carbon Composite ◽  
Waste Biomass ◽  
Innovative Method ◽  
Carbon Composite Material ◽  
Plant Waste ◽  
Carbon Composite Materials ◽  
Novel Method

Hierarchical nanotubes@mesoporous carbon composite materials were controllably synthesized by an innovative method based on plant waste corncob and nitrogen source melamine via thermal treatment.

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