Elastic Compression of a Fiber Network

1995 ◽  
Vol 62 (1) ◽  
pp. 223-226 ◽  
Author(s):  
S. Toll ◽  
J.-A. E. Manson
Keyword(s):  
Constitutive Equation ◽  
Aspect Ratio ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Orientation Distribution ◽  
Large Aspect Ratio ◽  
Transverse Compression ◽  
Fiber Network ◽  
Fiber Orientation Distribution ◽  
Uniform Diameter

A constitutive equation for a planar fiber network under transverse compression is derived allowing for an in-plane fiber orientation distribution. The fibers are assumed to be well dispersed in space and to have a large aspect ratio and uniform diameter. A compression experiment, performed on a glass-fiber network obtained by ashing a commercial composite preform, is accurately described by the theory.

Development of the layered structure in a double-gated glass fiber-reinforced polypropylene injection molding: Experimental and simulated results

2018 ◽  
Vol 37 (14) ◽  
pp. 945-959 ◽  
Author(s):  
MC Quintana ◽  
MP Frontini
Keyword(s):  
Glass Fiber ◽  
Layered Structure ◽  
Fiber Orientation ◽  
Flow Direction ◽  
Weld Line ◽  
Orientation Distribution ◽  
Simulation Software ◽  
Distribution Data ◽  
Melt Temperature ◽  
Fiber Orientation Distribution

The present study aims to experimentally validate numerical simulation of fiber orientation distribution performed by molding simulation software Moldex3D in a double-gated injection-molded glass fiber-filled (40 wt%) polypropylene box, by making a detailed comparison of predicted and experimentally measured fiber orientation distribution data. The modeling approach evaluated in this work consists in the implementation of the Folgar–Tucker rotary diffusion model with the invariant-based optimal fitting closure approximation for the fourth-order orientation tensor. The specimen used has a weld line in the center and sharp corners. This investigation characterizes in detail the development of the through-thickness layered structure at distinctive locations of the specimen. The sensitivity of fiber orientation distribution and the layered structure to changes upon injection time and melt temperature is also evaluated. The boxes display the typical layered laminate structure, with fibers aligned in the main flow direction near the walls (shell layer) and less oriented in the middle plane (core layer). The boxes injected at the lowest melt temperature display an additional skin layer. Unfortunately, simulation fails in predicting the five layers structure developed under these latter conditions. The grade of fiber orientation is deemed to be independent of process parameters but not the layered structure.

Correlation between fiber orientation distribution and mechanical anisotropy in glass-fiber-reinforced composite materials

2019 ◽  
Vol 39 (7) ◽  
pp. 653-660 ◽  
Author(s):  
Senji Hamanaka ◽  
Chisato Nonomura ◽  
Thanh Binh Nguyen Thi ◽  
Atsushi Yokoyama
Keyword(s):  
Glass Fiber ◽  
Fiber Orientation ◽  
Flexural Modulus ◽  
Orientation Distribution ◽  
Fiber Content ◽  
Mechanical Anisotropy ◽  
Bending Test ◽  
Flat Plates ◽  
Fiber Orientation Distribution ◽  
Injection Molded

Abstract This study investigates the correlation between the fiber orientation distribution along the thickness and mechanical anisotropy in injection-molded products using a thermoplastic resin reinforced by short fibers. To this end, polyamide-6 samples containing 15, 30, 50, and 65 wt% of short fiberglass were compounded, and flat plates with side gates were injection-molded. The fiber orientation distribution near the center of the plates was observed via X-ray computed tomography and that along the thickness was quantified via a fiber orientation tensor. Coupon test pieces were cut from the plates along the machine and transverse directions, and a three-point bending test was performed. Mechanical anisotropy was evaluated from the ratio of the flexural modulus in each direction. Evaluation results of the fiber orientation distribution and mechanical anisotropy were compared. As a result of the above investigation, a clear correlation was found between the fiber orientation distribution and mechanical anisotropy when the glass fiber content was 15–50 wt%. In the anisotropic expression under the condition of high glass fiber content (65 wt%), contributions of parameters other than the fiber orientation distribution became evident.

Effect of Fiber Aspect Ratio and Area Ratio Getting to Accuracy of Intensity Method in Fiber Orientation Angle Distribution Measurement

2006 ◽  
Vol 326-328 ◽  
pp. 1817-1820
Author(s):  
Jin Woo Kim ◽  
Dong Gi Lee
Keyword(s):  
Aspect Ratio ◽  
Fiber Orientation ◽  
Orientation Angle ◽  
Orientation Distribution ◽  
Angle Distribution ◽  
Fiber Aspect Ratio ◽  
Orientation Function ◽  
Fiber Orientation Distribution ◽  
Fiber Orientation Angle ◽  
Distribution State

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.

Effect of Fiber Orientation on the Tensile Strength in Fiber-Reinforced Polymeric Composite Materials

2005 ◽  
Vol 297-300 ◽  
pp. 2897-2902 ◽  
Author(s):  
Jin Woo Kim ◽  
Jung Ju Lee ◽  
Dong Gi Lee
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Fiber Orientation ◽  
Polymeric Composite ◽  
Orientation Distribution ◽  
Fiber Content ◽  
Fiber Reinforced ◽  
Composite Sheet ◽  
Content Ratio ◽  
Fiber Orientation Distribution

The study for strength calculation of one way fiber-reinforced composites and the study measuring precisely fiber orientation distribution were presented. However, because the DB that can predict mechanical properties of composite material and fiber orientation distribution by the fiber content ratio was not constructed, we need the systematic study for that. Therefore, in this study, we investigated what effect the fiber content ratio and fiber orientation distribution have on the strength of composite sheet after making fiber reinforced polymeric composite sheet by changing fiber orientation distribution with the fiber content ratio. The result of this study will become a guide to design data of the most suitable parts design or fiber reinforced polymeric composite sheet that uses the fiber reinforced polymeric composite sheet in industry spot, because it was conducted in terms of developing products. We studied the effect the fiber orientation distribution has on tensile strength of fiber reinforced polymeric composite material and achieved this results below. We can say that the increasing range of the value of fiber reinforced polymeric composite’s tensile strength in the direction of fiber orientation is getting wider as the fiber content ratio increases. It shows that the value of fiber reinforced polymeric composite’s tensile strength in the direction of fiber orientation 90° is similar with the value of polypropylene’s intensity when fiber orientation function is J= 0.7, regardless of the fiber content ratio. Tensile strength of fiber reinforced polymeric composite is affected by the fiber orientation distribution more than by the fiber content ratio.

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