Comparison of Intensity Method and Counting Method in Measurement of Fiber Orientation Angle Distribution Using Image Processing

2007 ◽  
Vol 544-545 ◽  
pp. 207-210
Author(s):  
Jin Woo Kim ◽  
Dong Gi Lee

The fiber reinforced composites has high specific strength and stiffness than metallic material and are an anisotropic material whose mechanical properties, such as strength and elasticity, change with their fiber orientation state, the fiber length, the fiber aspect ratio, fiber mat structure, etc. Above all, the fiber orientation angle distribution state of fiber reinforced composite is fundamental element of mechanical properties. So, many researches on this element have been conducted by means of nondestructive method currently. The fiber distribution state is measured by intensity difference of pixel using image processing and these methods are intensity method by calculating of intensity value of pixel and counting method by calculating of fiber quantity. In this research, the fiber orientation simulation picture was constructed by plotter according to change of fiber’s diameter, length and orientation. The fiber orientation distribution state was measured by this intensity information. The fiber orientation angle distribution state measured by intensity method and counting method was compared with fiber orientation function calculation value.

2006 ◽  
Vol 324-325 ◽  
pp. 415-418
Author(s):  
Jin Woo Kim ◽  
Dong Gi Lee

While mold fiber reinforced composite material to problem of occasion that high temperature compression molding, flow length in mold is overlong or when flow meets with resistance in side of mold, fiber orientation happens and big change occurs in strength or quality. Thus, in compression molding that use fiber reinforced composite material, orientation state of fiber in moldings is the most basic element that quotes various properties of matter values. Therefore, to clear orientation state of fiber establishing measurement of fiber orientation angle distribution is very important while give correction of molding condition decision, mechanical quality of moldings and guide about material design. In the study, the fiber orientation distribution of simulation figure plotted by PC is measured using image processing in order to examine the accuracy of intersection counting method. The fiber orientation function measured by intersection counting method using image processing is compared with the calculated fiber orientation function. The results show that the measured value of fiber orientation function using intersection counting method is lower than the calculated value, because the number of intersection between the scanning line and the fiber with smaller fiber aspect ratio is counted less than with larger fiber aspect ratio.


2006 ◽  
Vol 326-328 ◽  
pp. 1817-1820
Author(s):  
Jin Woo Kim ◽  
Dong Gi Lee

Measurement of fiber orientation distribution state is very important constituent to find out decision of processing condition of product or mechanical special quality of moldings in fiber reinforced polymer composite material. Therefore, reliable measurement method of fiber orientation angle distribution is established, and need researcher about simplicity measuring method urgently the nondestructiveness. In this research, to investigate about accuracy of fiber orientation angle distribution measurement of fiber reinforced composite material by intensity method, find fiber orientation function value that is measure of fiber orientation distribution state constructing fiber orientation simulation picture by plotter changing diameter and length and orientation state of fiber. Recognize this fiber orientation simulation picture by image scanner, and measure fiber orientation angle distribution state by this realized intensity information. This time, I wish to measure reliable fiber orientation angle distribution comparing fiber orientation function calculation value saving in the advance with fiber orientation function value that is measured by intensity method. The results show that measurement accuracy of the fiber orientation angle distribution by intensity method is affected by the fiber aspect ratio when the total length of oriented fiber is same. The average gradient of fiber orientation function is 0.94 for 1000mm of the total fiber length and is 0.93 for 2000mm when the fiber aspect ratio is over 50. Measurement accuracy by intensity method is about 94% and the reliable data can be obtained by intensity method.


1998 ◽  
Vol 7 (4) ◽  
pp. 096369359800700 ◽  
Author(s):  
VK Ganesh ◽  
S Ramakrishna ◽  
HJ Leck

A method of fabricating fiber-reinforced composite based functionally gradient material is described in this paper. The material has continuously varying mechanical properties along the length. The continuous variation of the mechanical properties is achieved by continuously varying the fiber orientation using the braiding process. The test results indicate an elastic modulus increase by about 42% from the largest braid angle to the smallest braid angle for the material system and the orientation angle considered in the present study.


2014 ◽  
Vol 887-888 ◽  
pp. 1246-1250 ◽  
Author(s):  
Zhi Kai Li ◽  
Dong Lu ◽  
Qiang Wang ◽  
Yong Bo Wu

This work is focused on the study of orthogonal cutting of carbon fiber reinforced composite. A model based on finite element was developed. Through defining ultimate stresses of fiber tension cracking and fiber compression bucking, ultimate stresses of matrix longitudinal tensile and shear damage. Cutting forces obtained from the FE simulation matches well with the experimental observations. Than analysis cracking and crushing phenomenon of matrix in different fiber orientation, the influence of fiber orientation on sub-surface damage was studied, it shows that the cracking of sub-surface damage value increased with the increase of fiber orientation angle.


2015 ◽  
Vol 776 ◽  
pp. 253-259
Author(s):  
Winarto ◽  
W. Eddy ◽  
R. Liza ◽  
H. Syamsul

This research has been carried out in order to analyse the possibility of fiberglass woven roving used as an alternative material for the hull of of fishing boat. The standard used in this analyzing process was the Standard of Biro Klasifikasi Indonesia (BKI), especially to find how the forces applied to the boat. Once the forces were found, they would be applied to justify the possibility mentioned above. The justification process was done by theoretically analyzing the mechanical properties of some fiberglass woven roving composites using mathematical software. The composites have been made by varying the mixture volume fraction between 0% - 100% within 10% interval, fiber orientation angle between 0o – 90o within 5o interval, and then the results which met the requirements according to BKI Standard would be justified by the results obtained from experimental analysis. Based on the experimental analysis results, it could be stated that the fiberglass woven roving with composition of 40% - 60% and fiber orientation angle 0o can be used as an alternative material for the hull of fishing boat.


2020 ◽  
Vol 10 (11) ◽  
pp. 3693
Author(s):  
Linxian Gong ◽  
Lei Nie ◽  
Yan Xu

Soil reinforcement with natural or synthetic fibers enhances its mechanical behavior in various applications. Fiber-reinforced sands (FRS) can be relatively anisotropic because of the fiber self-weight and the compaction technique. However, the microscopic mechanisms underlying the anisotropy are still poorly understood. This study used a discrete element approach to analyze the microscopic mechanisms underlying the strength anisotropy of FRS due to fiber orientation. Analysis of contact networks revealed that the optimum fiber orientation angle is perpendicular to the main direction of strong contact force in direct shear testing. These fibers produced the largest increase in shear zone thickness, normal force around the fiber body, effective contact area, tensile force along fibers, and energy storage/dissipation. This study is valuable for further understanding of the mechanical behaviors of FRS.


2018 ◽  
Vol 37 (13) ◽  
pp. 905-916 ◽  
Author(s):  
Qinglong An ◽  
Jie Chen ◽  
Xiaojiang Cai ◽  
Tingting Peng ◽  
Ming Chen

Carbon fiber reinforced polymer has been used as a major material for primary load-bearing structural components in aviation industry. But its poor heat resistance is an important factor affecting the machining performance, because high cutting temperature above glass transition temperature of resin matrix (normally 300°C or below) may lead to the degradation of the resin matrix. In this study, orthogonal machining experiments were conducted to investigate the effects of cutting parameters, cutting tool geometric parameters, and material parameters on cutting temperature, and the prediction model of cutting temperature about fiber orientation angle ( θ) was built. Cutting temperature was measured by semiartificial thermocouple method. The experimental results revealed that the influence of cutting parameters on cutting temperature was not affected by fiber orientation angle of carbon fiber reinforced polymer. Cutting tool geometric parameters have little effect on cutting temperature. Unlike metal materials, cutting temperature was greatly influenced by θ. Cutting temperature for θ < 90° was significantly higher than that for θ > 90°. The maximum temperature occurred at θ = 90°. The influence of fiber orientation angle was shown in two aspects: changing the springback of unidirectional-carbon fiber reinforced polymer laminates in cutting process, changing material removal mechanism, which affected cutting temperature eventually.


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