Neutron darkfield imaging of fiber composites

2021 ◽  
Vol 63 (7) ◽  
pp. 623-629
Author(s):  
André Hilger ◽  
Nikolay Kardjilov ◽  
Axel Lange ◽  
Andreas Kupsch ◽  
Manfred P. Hentschel ◽  
...  
Keyword(s):  
Fiber Composites ◽  
Fiber Direction ◽  
Basic Principles ◽  
X Ray ◽  
Glass Fiber Composites ◽  
Reinforced Plastics ◽  
Strong Signal ◽  
Fiber Reinforced Plastics ◽  
Darkfield Imaging ◽  
Signal Response

Abstract While X-ray based darkfield imaging with grating interferometers is already widely used, darkfield imaging with neutrons has still a relatively small user community focused mostly on magnetic materials. Here, we demonstrate the application of neutron darkfield imaging byTalbot-Lau type grating interferometry to fiber reinforced plastics. Common carbon and glass fiber composites have been investigated including characteristic damage structures. The darkfield images show a strong signal response caused by fiber delamination, suitable fiber direction, particles, pores and cracks. The basic principles of neutron darkfield imaging applied to fiber composites are highlighted.

scholarly journals Residual Stress Evaluation of Short-Fiber Reinforced Plastics by X-Ray Diffraction

2014 ◽  
Vol 996 ◽  
pp. 951-957
Author(s):  
Keisuke Tanaka ◽  
Yuuki Koike ◽  
Yoshiaki Akiniwa
Keyword(s):  
Skin Layer ◽  
Short Fiber ◽  
Fiber Direction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reinforced Plastics ◽  
Stress Partitioning ◽  
The Matrix ◽  
Partitioning Coefficients ◽  
Fiber Reinforced Plastics

The X-ray diffraction method is used to evaluate the residual stress in injection-molded plates of short-fiber reinforced plastics (SFRP) made of crystalline thermoplastics, polyphenylene sulphide (PPS), reinforced by carbon fibers with 30 mass%. The stress in the matrix in the skin layer was determined using Cr-Kα radiation with the sin2 ψ method. The X-ray evaluation of stress in carbon fibers was not possible because of high texture. A new method was proposed to evaluate the macrostress in SFRP from the measurement of the matrix stress. According to micromechanics analysis of SFRP, the matrix stresses in the fiber direction and perpendicular to the fiber direction, and shear stress can be expressed as linear functions of the applied (macro-) stresses in the fiber direction and perpendicular to the fiber direction, and shear stress. The proportional constants are named stress-partitioning coefficients. Using skin-layer strips cut parallel, perpendicular and 45° to the molding direction, the stress in the matrix was evaluated under the uniaxial applied stress and the stress-partitioning coefficients of the above equations were determined. Once the relations between the macrostress and matrix stress are established, the macrostress in SFRP can be evaluated from the measurements of the matrix stresses using X-rays.

Experimental Study on Delamination during Trimming of CFRP

2015 ◽  
Vol 1089 ◽  
pp. 331-336 ◽  
Author(s):  
Qing Liang Chen ◽  
Jing Wen Zhou ◽  
Xue Mei Chen ◽  
Yan Chen ◽  
Yu Can Fu
Keyword(s):  
Experimental Study ◽  
Carbon Fiber ◽  
Great Influence ◽  
Fiber Direction ◽  
Type I ◽  
Cfrp Laminates ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Inclined Angle

Carbon fiber reinforced plastics (CFRP) laminates with different top/bottom fiber direction angle (stacking sequences of each ply) are trimmed at various workpiece inclined angles. Four types of delamination are studied and discussed. The results indicate that fiber direction has great influence on the type of delamination and the workpiece inclined angle determines the proportion of each type of delamination expect a special cast that the delamination form turns into type I/II when the workpiece inclined angle is 58.6o. Stacking sequences of each ply have great influence on the numbers of damaged plies and the 0o fiber direction ply has the ability to prevent the development of damaged ply.

Milling of Carbon Fiber Reinforced Plastics

2009 ◽  
Vol 83-86 ◽  
pp. 49-55 ◽  
Author(s):  
Luis Norberto López de Lacalle ◽  
Aitzol Lamikiz
Keyword(s):  
Carbon Fiber ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Left Hand ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Cutting Length ◽  
Fiber Reinforced Plastics ◽  
Definition Of ◽  
Milling Tools

This work presents the main results of several tests carried out to define the best milling tools for routing carbon fiber reinforcement plastics, mainly in use for airframes. The new milling tools are shaped by multiple left-hand and right-hand helical edges, which form small pyramidal edges along the cutting length. Several carbide substrates and coatings were tested. After the analysis of tests and modifications on the tool prototypes, the final results allow the definition of routing endmills optimized for carbon fiber composites.

Theoretical Analysis of Grinding Temperature Field for Carbon Fiber Reinforced Plastics

2010 ◽  
Vol 126-128 ◽  
pp. 52-57 ◽  
Author(s):  
Hang Gao ◽  
H.L. Ma ◽  
Yong Jie Bao ◽  
H.P. Yuan ◽  
Ren Ke Kang
Keyword(s):  
Temperature Field ◽  
Carbon Fiber ◽  
Theoretical Analysis ◽  
Fiber Direction ◽  
Grinding Temperature ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Grinding Temperature Field

A three-dimensional finite difference method (FDM) model of grinding temperature field for carbon fiber reinforced plastics (CFRP) was established, based on the homogenization of the thermal properties of the CFRP material. The effect of the fiber direction on grinding temperature distribution at different workpiece velocity was numerically simulated and analyzed. It is found that the effect of the fiber direction on grinding temperature field is remarkable in lower workpiece velocity but unapparent in higher workpiece velocity due to the anisotropy of CFRP material and the velocity of moving heat source. More than 230 °C surface grinding temperature, which will badly damage CFRP performance, may be produced in dry grinding according to the simulated analysis. During grinding the heat affected zone of CFRP is about 0.22 mm in depth direction. Furthermore, experimental results are well in agreement with those of the theoretical analysis.

MICROSTRUCTURAL CORRELATIONS IN SHORT-ALIGNED GLASS FIBER COMPOSITES

2021 ◽  
Author(s):  
CAMILO A. ROJAS G., ◽  
ERICH SCHÖBERL ◽  
MARCO L. LONGANA ◽  
STEPAN LOMOV ◽  
YENTL SWOLFS
Keyword(s):  
Orientation Distribution ◽  
Fiber Composites ◽  
Added Value ◽  
X Ray ◽  
Glass Fiber Composites ◽  
Fiber Orientation Distribution ◽  
Measurable Parameter ◽  
Recycled Fiber ◽  
X Ray Computed ◽  
Fiber Breaks

Research shows that in unidirectional composites, fiber breaks and clusters of fiber breaks play a role in the failure onset of the composites [1]. So far, we know no attempts to the date have been made to analyze the fiber break development in short-aligned fiber composites, specifically using E-glass HYBON 2026. O[1]ur challenge is to determine whether there is a similar behavior in aligned short composites and its relationship with the microstructural parameter of fiber orientation distribution. This is important as it is measurable parameter to add value to recycled fiber composites. The more aligned the composite the higher mechanical properties and the higher the added value for recycling. We focused on using synchrotron x-ray computed tomography while performing hold-at-displacement scans to evaluate the fiber microstructure. We found the fiber breaks do not have the same orientation distribution as the non-broken fibers.

Position-Resolved Small-Angle X-ray Scattering of Complex Biological Materials

1997 ◽  
Vol 30 (5) ◽  
pp. 765-769 ◽  
Author(s):  
P. Fratzl ◽  
H. F. Jakob ◽  
S. Rinnerthaler ◽  
P. Roschger ◽  
K. Klaushofer
Keyword(s):  
Small Angle ◽  
Biological Materials ◽  
Fiber Composites ◽  
Fiber Direction ◽  
Mechanical Function ◽  
X Ray ◽  
Area Detector ◽  
X Ray Scattering ◽  
The Individual ◽  
Ray Scattering

Many biological materials, like bone or wood, are hierarchically organized and optimized at all levels for their specific mechanical function. At the lowest level, these materials are fiber composites, where the fiber direction as well as the size of the individual components varies considerably with position inside a given specimen. For bone or wood, some of these parameters can be readily obtained by small-angle X-ray scattering (SAXS) in a position-resolved way. A scanning-SAXS system based on a pinhole camera with rotating anode and area detector is presented, and first applications to the study of bone and wood are reported.

Glass Fiber Permeability Using the VARTM Process

2010 ◽  
Vol 97-101 ◽  
pp. 1772-1775 ◽  
Author(s):  
Yun Hae Kim ◽  
Dong Hun Yang ◽  
Chang Won Bae ◽  
Kyung Man Moon ◽  
Young Dae Jo ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Rate Control ◽  
Velocity Vector ◽  
Fiber Composites ◽  
Fiber Direction ◽  
Transfer Molding ◽  
Glass Fiber Composites ◽  
Reinforcement Fiber ◽  
Flow Rate Control ◽  
Vartm Process

This study investigated a flow rate control system for the vacuum-assisted resin transfer molding (VARTM) process. Using Darcy’s equation, the permeability of multiaxial glass fiber composites is predicted and experimentally confirmed. The resin velocity vector is inversely proportional to the fiber mat length and resin viscosity, but proportional to the fiber mat permeability. In this study, the permeability of the preform and viscosity of the epoxy resin were measured using multiaxial glass fiber by VARTM. The permeability and time for impregnation differed according to the fiber direction in the VARTM process. The results indicated the need for further study of reinforcement fiber permeability in VARTM processing design.

OS1816 A New X-Ray Method of Residual Stress Measurement of Short-Fiber Reinforced Plastics

2013 ◽  
Vol 2013 (0) ◽  
pp. _OS1816-1_-_OS1816-3_
Author(s):  
Keisuke TANAKA ◽  
Shohei TOKORO ◽  
Yuuki KOIKE ◽  
Noboru EGAMI ◽  
Yoshiaki AKINIWA
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Short Fiber ◽  
Residual Stress Measurement ◽  
Fiber Reinforced ◽  
Ray Method ◽  
X Ray ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics
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