scholarly journals Composite Materials. Effect of Interphase Properties on Initial Damage in Embedded Single Fiber Transverse Tensile Test.

1999 ◽  
Vol 48 (5) ◽  
pp. 446-453 ◽  
Author(s):  
Kazuaki NISHIYABU ◽  
Atsushi YOKOYAMA ◽  
Masaru ZAKO
Keyword(s):  
Composite Materials ◽  
Tensile Test ◽  
Single Fiber ◽  
Transverse Tensile ◽  
Initial Damage

Short Carbon Fibers Composites With High Filler Contents Rheology and Mechanical Properties

1999 ◽  
Author(s):  
Y. Schmitt ◽  
C. Paulick ◽  
Y. Bour ◽  
F. X. Royer
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Tensile Test ◽  
Carbon Fibers ◽  
Polymer Materials ◽  
Complex Geometries ◽  
Small Ratio ◽  
The Matrix ◽  
Short Carbon

Abstract The control of the quality of mixture based on very short carbon fibers and epoxyde resins leads to suitable mixture for molding of complex geometries. A gain in fluidity is obtained if the suspensions are treated by ultrasounds and simultaneously stirred under vacuum. Addition in a very small ratio of microbubbles in the mixture allows to obtain a viscosity less than those of the matrix alone. For many polymer materials the gain of fluidity can be of 20 to 25% with size and concentration of the microspheres thoroughly chosen. A certain number of new resins is developped to elaborate composite materials with specific mechanical properties close to standard aluminium. Tensile test an ultimate stress are used to quantify the improvements of the mechanical properties. Fillers concentrations up to 30 % are obtained.

Rheological Study on Multiple Fiber Suspensions for Fiber Reinforced Composite Materials Processing

2011 ◽  
Author(s):  
Dongdong Zhang ◽  
Douglas E. Smith ◽  
David A. Jack ◽  
Stephen Montgomery-Smith
Keyword(s):  
Composite Materials ◽  
Hydrodynamic Forces ◽  
Single Fiber ◽  
Hydrodynamic Interactions ◽  
Materials Processing ◽  
Fiber Suspensions ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Mechanical Contacts

This paper studies the rheological properties of a semi-dilute fiber suspension for short fiber reinforced composite materials processing. For industrial applications, the volume fraction of short fibers could be large for semi-dilute and concentrated fiber suspensions. Therefore, fiber-fiber interactions consisting of hydrodynamic interactions and direct mechanical contacts could affect fiber orientations and thus the rate of fiber alignment in the manufacturing processing. In this paper, we study the semi-dilute fiber suspensions, i.e. the gap between fibers becomes closer, and hydrodynamic interactions becomes stronger, but the physical/mechanical contacts are still rare. We develop a three-dimensional finite element approach for simulating the motions of multiple fibers in low-Reynolds-number flows typical of polymer melt flow. We extend our earlier single fiber model to consider hydrodynamic interactions between fibers. This approach computes the hydrodynamic forces and torques on fibers by solving governing equations of motion in fluid. The hydrodynamic forces and torques result from two scenarios: gross fluid motion and hydrodynamic interactions from other fibers. Our approach seeks fibers’ velocities that zero the hydrodynamic torques and forces acting on the fibers by the surrounding fluid. Fiber motions are then computed using a Runge-Kutta approach to update fiber positions and orientations as a function of time. This method is quite general and allows for solving multiple fiber suspensions in complex fluids. Examples with fibers having various starting positions and orientations are considered and compared with Jeffery’s single fiber solution (1922). Meanwhile, we study the effect of the presence of a bounded wall on fiber motions, which is ignored in Jeffery’s original work. The possible reasons why fiber motions observed in experiments align slower than those predicted by Jeffery’s theory are discussed in this paper.

The effect of interphase on residual thermal stresses. 1. Single fiber composite materials

1995 ◽  
Vol 30 (5) ◽  
pp. 417-425 ◽  
Author(s):  
V. Kushnevsky ◽  
G. Wacker ◽  
A. Chate ◽  
A. K. Bledzki
Keyword(s):  
Composite Materials ◽  
Thermal Stresses ◽  
Fiber Composite ◽  
Single Fiber ◽  
Fiber Composite Materials

Fatigue Life of Hybrid Composites (DGEBA)

2020 ◽  
Vol 398 ◽  
pp. 54-59
Author(s):  
Nisreen Mizher Rahma ◽  
Lubna Ghalib ◽  
Khalid Mershed Eweed
Keyword(s):  
Composite Materials ◽  
Tensile Test ◽  
Glass Fiber ◽  
Fatigue Limit ◽  
Fatigue Test ◽  
Hybrid Composite ◽  
Fiber Type ◽  
Second Stage ◽  
Number Of Layers ◽  
Two Stages

This study presents the experimental results of the influence of mechanical fatigue and tensile on hybrid composite materials. Epoxy with Novolac resin are used as matrix for the reinforced materials that consist of glass fiber type E. The slates made of hybrid composite materials for two proportions (80% epoxy, 20% Novolac) and (60% epoxy, 40% Novolac) were reinforced by three volume fractions (10%, 20% and 30%) of glass fiber type (E), where been manufacturing (6) panels of hybrid composite materials, all these panels cutting into two groups samples with dimension (70x 10) mm in order to execute the fatigue test and (150x20) mm for tensile test, according to the specifications of the device used.The process took place in two stages: The two stages include executing the fatigue and tensile test specimens with a ratio (80% epoxy, 20% Novolac) in the first stage and (60% epoxy, 40% Novolac) in the second stage for the volume fractions (10%, 20% and 30%) of glass fiber type (E) and comparison the results between them for each stage. The results obtained from fatigue test in the first stage showed that the number cycle for fatigue limit decreased when the load and the number of layers of reinforcing are increased. But in the tensile test for the samples the results showed that the value of the elongation increasing to the point of failure when the load increased for the same layers of reinforcement, as well as the value of elongation decreasing to a failure when increased the number of layers of reinforcing glass fibers type (E) for the same load. The results of tensile and fatigue test obtained from the second stage showed similar to the results in the first stage, but the cycle number of fatigue limit less value from the first stage and the stress was higher in the fatigue test. For tensile test the elongation values ​​less and the stress values higher for the same volume fraction of the reinforcement due to increase in the proportion of Novolac.

Possibility of Usage of Aluminium Rivet Nuts Connections in Composite Materials

2015 ◽  
Vol 240 ◽  
pp. 137-142 ◽  
Author(s):  
Radosław Bielawski ◽  
Michał Kowalik ◽  
Karol Suprynowicz ◽  
Paweł Pyrzanowski
Keyword(s):  
Composite Materials ◽  
Tensile Test ◽  
Composite Structures ◽  
Test Method ◽  
Damage Models ◽  
Constant Torque ◽  
Composite Damage ◽  
Composites Materials ◽  
Riveted Joints ◽  
Static Tensile

Development and application of composite materials in modern industry are very dynamic. Composite materials seem to be replacing steel and aluminium ones. Composites are a cheaper solution, with similar mechanical strengths. Generally, there are two types of joints in composite structures: mechanical and adhesively bonded ones. The aim of the study was to determine the feasibility of riveted joints in composites materials. Static tensile test method was used. In the test there was used one type of glass fabric (Interglas 92140) from which two types of composite samples were prepared. In each sample there was used the same type of fiber with the same fiber orientation – 3 layers. Samples had dimensions of 220x100 mm and thickness of approximately 1.5 mm. They were connected to each other with aluminium rivet nuts (from 1 to 3) and placed in a metal frame with a screw connection which was made of screws with nominal thread pitch M5. Screws were tightened with constant torque. It was to provide an axial force to the sample during the tensile test. The frame was placed between cross-bars of tensile machine INSTRON 8516. The samples were stretched at a speed of 0.05 mm/s at a distance up to 20 mm. During the tensile test displacement of the samples and pull force were registered. Depending on the fiber orientations and number of rivet nuts composite damage models were described. On the basis of the results the possibility of usage of aluminium rivet nuts connections in composite materials was determined.

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