A Novel 3-D Braiding Technology, Complex Shape Preforms and Composites

2002 ◽  
Author(s):  
Alexander Bogdanovich ◽  
Dmitri Mungalov
Keyword(s):  
Cross Section ◽  
Composite Structures ◽  
Complex Shape ◽  
Mechanical Characterization ◽  
Industrial Scale ◽  
Glass Composites ◽  
Box Beams ◽  
Switch Mechanism ◽  
Unlimited Variety

A brief overview of 3-D braiding technology and its two major branches, “row and column” and “rotary” braiding, opens the paper. An innovative 3-D braiding process that has been recently patented and implemented in a fully automated multi-modular industrial scale machine is introduced next. The machine enables producing complex, continuously variable shape preforms for composite structures. Each module of the machine incorporates some number of horngears with four yarn carriers placed on each of them. A novel gate switch mechanism, based on the gripping fork controlled rotation, provides smooth transfer of yarn carriers between adjacent horngears. Each gripping fork is controlled individually, thus allowing fabricating practically unlimited variety of complex cross section 3-D braided preforms. Examples of manufactured braided products include rectangular bars, T-, I- and J-stiffeners, box-beams, hollow tubes, etc. Results and discussion of mechanical characterization of 3-D braided carbon and E-glass composites conclude the paper.

USE OF SPATIOTEMPORAL DIAGRAMS TO CHARACTERIZE A SILO DISCHARGING PROCESS

2013 ◽  
Vol 37 (1) ◽  
pp. 53-70
Author(s):  
Blaise Nsom ◽  
Noureddine Latrache
Keyword(s):  
Cross Section ◽  
Flow Rate ◽  
Mechanical Characterization ◽  
Direct Method ◽  
Rectangular Cross Section ◽  
Small Scale ◽  
Flat Bottom ◽  
Shear Box ◽  
A Direct Method

To get a better knowledge of discharging flows of ensiled granular materials, a small scale silo was designed and built. It is equipped with a flat bottom and it has a rectangular cross section. Moreover, it is entirely transparent for image processing purpose. First of all, a physical and mechanical characterization of wood granules (inert materials) was performed using a shear box testing. Then, silo emptying flows were generated. Flow regimes and flow rate were determined using spatiotemporal diagrams extracted from images of the free surface of the ensiled material. The same method was then used to measure the flow rate of discharging flows of soya, colza and rye seeds which were characterized in a previous study. For each material studied, the flow rate measured with this non intrusive method was successfully compared with a direct method consisting in weighing a volume of grains discharged during a unit time and with Berveloo’s formula.

Behavior of composite advanced pore morphology foam

2011 ◽  
Vol 45 (26) ◽  
pp. 2823-2831 ◽  
Author(s):  
Matej Vesenjak ◽  
Franci Gačnik ◽  
Lovre Krstulović-Opara ◽  
Zoran Ren
Keyword(s):  
Mechanical Properties ◽  
Epoxy Matrix ◽  
Composite Structures ◽  
Mechanical Characterization ◽  
Experimental Testing ◽  
Compressive Loading ◽  
Metallic Foam ◽  
Pore Morphology ◽  
Computational Simulations

The mechanical characterization of advanced pore morphology (APM) foam, consisting of sphere-like metallic foam elements, is very limited since APM foam has been developed only recently. The purpose of this research was thus to determine the behavior of APM spheres and its composites when subjected to compressive loading. Single metallic APM spheres have been characterized with experimental testing and computational simulations, providing the basic properties and knowledge for an efficient composition of composite APM foam structures. Then, the APM foam elements were molded with epoxy matrix resulting in new composite structures. These composites have been adhered together with the epoxy resin achieving partial and syntactic morphology. The mechanical characterization of composite APM foam structures was based on experimental testing results with free and confined boundaries. The results of the performed research have shown valuable mechanical properties of the composite APM foam structures. Furthermore, they offer new possibilities for their use in general engineering applications.

Microtexture Studies of Extruded Aluminum Using Electron Backscatter Diffraction

2001 ◽  
Vol 7 (S2) ◽  
pp. 374-375
Author(s):  
S. R. Claves ◽  
W. Z. Misiolek ◽  
D. B. Williams
Keyword(s):  
Cross Section ◽  
Complex Shape ◽  
Electron Backscatter Diffraction ◽  
Rectangular Shape ◽  
Porthole Die ◽  
Electron Backscatter ◽  
Grain Orientations ◽  
Backscatter Diffraction ◽  
Longitudinal Welds

Electron backscatter diffraction (EBSD) is a powerful tool used for the characterization of deformed microstructures and has been successfully applied to determine the microtexture of specific regions of bulk samples. The work presented here is a continuation of previous analyses investigating the microstructural response of 6xxx aluminum extrudates to complex die designs. Specifically, the grain orientations across longitudinal welds produced from porthole dies is being studied.Previous work examined the cross section of a sample that was extruded using a specially designed die that would position the weld in the center of the part. This specimen, shown in Figure 1, is a simple, solid, rectangular shape produced under controlled conditions. The other sample being studied, seen in Figure 2, was part of an actual extrusion run, conducted with typical industrial parameters. This sample is part of a complex shape that uses a porthole die to produce hollow sections.

Fracture mechanical characterization of mica-filled epoxy glass composites under monotonic and cyclic loading

2018 ◽  
Vol 53 (6) ◽  
pp. 741-751
Author(s):  
Harish Kalyan Ram Pothukuchi ◽  
Peter Fuchs ◽  
Gerald Pinter ◽  
Steffen Stelzer
Keyword(s):  
Cyclic Loading ◽  
Mixed Mode ◽  
Mechanical Characterization ◽  
Fixed Ratio ◽  
Critical Energy ◽  
Weak Interface ◽  
Critical Energy Release Rate ◽  
Glass Composites ◽  
Winding Insulation

Stator insulations comprised of mica-filled epoxy glass composite materials are of paramount importance for the reliability of high-voltage rotating machines. The present work deals with the fracture mechanical characterization of the winding insulation under conditions of monotonic and cyclic loading. The identification and quantification of the weak interfaces in the material that will most likely result in the initiation and propagation of defects are investigated in detail. Material specimens are processed from insulation tapes, and tests are conducted under mode I, mode II and mixed mode (Fixed Ratio Mixed Mode) loading to characterize the weak interface. The influence of resin content on the strength of the weak interface is also investigated. The results give an indication of the delamination mechanism and a measure of the critical energy release rate in the insulation materials.

Mechanical Characterization of an Alternative Technique to Embed Sensors in Composite Structures: The Monitoring Patch

2011 ◽  
Vol 19 (3-4) ◽  
pp. 379-391 ◽  
Author(s):  
Mauricio Torres Arellano ◽  
Laurent Crouzeix ◽  
Francis Collombet ◽  
Bernard Douchin ◽  
Yves-Henri Grunevald
Keyword(s):  
Composite Structures ◽  
Mechanical Characterization ◽  
Alternative Technique

HRTEM simulation of interfacial structure in amorphous multilayers

1989 ◽  
Vol 47 ◽  
pp. 466-467
Author(s):  
Margaret L. Sattler ◽  
Michael A. O'Keefe
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Cross Section ◽  
High Resolution Electron Microscopy ◽  
Interfacial Structure ◽  
Multilayer Sample ◽  
Resolution Electron ◽  
Multilayered Materials ◽  
Simulated Images

Multilayered materials have been fabricated with such high perfection that individual layers having two atoms deep are possible. Characterization of the interfaces between these multilayers is achieved by high resolution electron microscopy and Figure 1a shows the cross-section of one type of multilayer. The production of such an image with atomically smooth interfaces depends upon certain factors which are not always reliable. For example, diffusion at the interface may produce complex interlayers which are important to the properties of the multilayers but which are difficult to observe. Similarly, anomalous conditions of imaging or of fabrication may occur which produce images having similar traits as the diffusion case above, e.g., imaging on a tilted/bent multilayer sample (Figure 1b) or deposition upon an unaligned substrate (Figure 1c). It is the purpose of this study to simulate the image of the perfect multilayer interface and to compare with simulated images having these anomalies.

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