scholarly journals Local fiber orientation from X-ray region-of-interest computed tomography of large fiber reinforced composite components

2019 ◽  
Vol 183 ◽  
pp. 107786 ◽  
Author(s):  
Thomas Baranowski ◽  
Dascha Dobrovolskij ◽  
Kilian Dremel ◽  
Astrid Hölzing ◽  
Günter Lohfink ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Fiber Orientation ◽  
Region Of Interest ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
X Ray ◽  
Reinforced Composite ◽  
Large Fiber ◽  
Local Fiber

Region-of-Interest X-Ray Tomography for the Non-Destructive Characterization of Local Fiber Orientation in Large Fiber Composite Parts

2019 ◽  
Vol 809 ◽  
pp. 587-593
Author(s):  
Simon Zabler ◽  
Katja Schladitz ◽  
Kilian Dremel ◽  
Jonas Graetz ◽  
Dascha Dobrovolskij
Keyword(s):  
Computed Tomography ◽  
Spatial Resolution ◽  
Fiber Orientation ◽  
Fiber Composite ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Anisotropic Thermal Conductivity ◽  
Local Fiber

To detect and characterize materials defects in fiber composites as well as for evaluatingthe three-dimensional local fiber orientation in the latter, X-ray micro-CT is the preferred methodof choice. When micro computed tomography is applied to inspect large components, the method isreferred to as region-of-interest computed tomography. Parts can be as large as 10 cm wide and 1 mlong, while the measurement volume of micro computed tomography is a cylinder of only 4 − 5 mmdiameter (typical wall thickness of fiber composite parts). In this report, the potentials and limits ofregion-of-interest computed tomography are discussed with regard to spatial resolution and precisionwhen evaluating defects and local fiber orientation in squeeze cast components. The micro computedtomography scanner metRIC at Fraunhofer‘s Development Center X-ray Technology EZRT deliversregion-of-interest computed tomography up to a spatial resolution of 2 μm/voxel, which is sufficientfor determining the orientation of natural or synthetic fibers, wood, carbon and glass. The mean localfiber orientation is estimated on an isotropic structuring element of approximately 0.1 mm length bymeans of volume image analysis (MAVI software package by Fraunhofer ITWM). Knowing the exactlocal fiber orientation is critical for estimating anisotropic thermal conductivity and materials strength.

Robotic Manufacturing of Near-Net Shaped Short-Fiber Reinforced Composites With Functional Properties

2009 ◽  
Author(s):  
Antony Paul ◽  
Jeffery M. Gallagher ◽  
Raymond J. Cipra ◽  
Thomas Siegmund
Keyword(s):  
Mechanical Properties ◽  
Fiber Orientation ◽  
Fiber Composite ◽  
Imaging Techniques ◽  
Short Fiber ◽  
Robotic Arm ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Geometric Data ◽  
Reinforced Composite

Fiber reinforced composite materials are now frequently being used over conventional materials for their ability to achieve tailored properties and performance characteristics. With the recent advancements in manufacturing techniques, short-fiber composites are coming into prominence in this sector, with their cost advantage and their capability for large throughput. Randomness of fiber orientation is inherent to short fiber composite manufacturing processes. In order to effectively manipulate the mechanical properties of a short-fiber reinforced composite, it is imperative to adequately control the orientation of the fibers during the deposition stage. A process is currently developed to acquire geometrical data of the target object and to utilize it to create a short-fiber reinforced component with controlled fiber orientation. The topological data acquisition of the object is made possible using non-contact 3D imaging techniques. The geometric data is then transferred to a commercial CAD package for the added capability to manipulate the geometry as may be required for specific applications. Subsequently, geometric data constitutes the basis of path planning for the tooling processes. In our process, a novel rapidly re-configurable tooling and molding technology is employed by which a 6-axis robotic arm is used to sculpt a pin-device vacuum surface. After the tooling is completed, the robotic arm will use a deposition nozzle to orient a steady stream of initially random short-fiber from a feeder into a unidirectional output, onto the tool surface. By controlling the position and orientation of the deposition nozzle, it is possible to control the orientation and density of fiber in each section of the near-net shaped composite pre-form. The fiber pre-form is then impregnated with a suitable matrix medium and cured to create the required component. The outlined process is thus capable of manufacturing a near-net shaped short-fiber reinforced component with highly specific mechanical properties. One of the many applications envisaged using this process is the manufacture of custom form-fitting braces, masks and guards for use in healthcare products. A patient intervention can have his or her features acquired using stereo-imaging and have corrective measures incorporated into the device prior to manufacturing. By controlling the orientation and density of the fiber at different portions of the device, it is possible to provide adequate support at specific areas or to restrict movement in specific directions while providing compliance to movement in the others.

scholarly journals Fiber Reinforced Composite Based Functionally Gradient Materials

1998 ◽  
Vol 7 (4) ◽  
pp. 096369359800700 ◽  
Author(s):  
VK Ganesh ◽  
S Ramakrishna ◽  
HJ Leck
Keyword(s):  
Mechanical Properties ◽  
Fiber Orientation ◽  
Orientation Angle ◽  
Gradient Material ◽  
Material System ◽  
Test Results ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Functionally Gradient

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.

Numerical Simulation of the Orthogonal Cutting of Carbon Fiber Reinforced Composite Material

2014 ◽  
Vol 887-888 ◽  
pp. 1246-1250 ◽  
Author(s):  
Zhi Kai Li ◽  
Dong Lu ◽  
Qiang Wang ◽  
Yong Bo Wu
Keyword(s):  
Carbon Fiber ◽  
Fiber Orientation ◽  
Orthogonal Cutting ◽  
Orientation Angle ◽  
Surface Damage ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Fiber Orientation Angle ◽  
Carbon Fiber Reinforced

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.

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