Plasma Modification of Graphite Fibers and Its Effect on Composite Properties.

1983 ◽  
Author(s):  
G. Dagli ◽  
N. H. Sung
Keyword(s):  
Plasma Modification ◽  
Graphite Fibers ◽  
Composite Properties

Design of Pipeline Composite Repairs: From Lab Scale Tests to FEA and Full Scale Testing

2014 ◽  
Author(s):  
Remy Her ◽  
Jacques Renard ◽  
Vincent Gaffard ◽  
Yves Favry ◽  
Paul Wiet
Keyword(s):  
Finite Element ◽  
Full Scale ◽  
Combined Loading ◽  
Material Strength ◽  
Repair System ◽  
Loading Conditions ◽  
Original Design ◽  
Composite Repair ◽  
Repair Systems ◽  
Composite Properties

Composite repair systems are used for many years to restore locally the pipe strength where it has been affected by damage such as wall thickness reduction due to corrosion, dent, lamination or cracks. Composite repair systems are commonly qualified, designed and installed according to ASME PCC2 code or ISO 24817 standard requirements. In both of these codes, the Maximum Allowable Working Pressure (MAWP) of the damaged section must be determined to design the composite repair. To do so, codes such as ASME B31G for example for corrosion, are used. The composite repair systems is designed to “bridge the gap” between the MAWP of the damaged pipe and the original design pressure. The main weakness of available approaches is their applicability to combined loading conditions and various types of defects. The objective of this work is to set-up a “universal” methodology to design the composite repair by finite element calculations with directly taking into consideration the loading conditions and the influence of the defect on pipe strength (whatever its geometry and type). First a program of mechanical tests is defined to allow determining all the composite properties necessary to run the finite elements calculations. It consists in compression and tensile tests in various directions to account for the composite anisotropy and of Arcan tests to determine steel to composite interface behaviors in tension and shear. In parallel, a full scale burst test is performed on a repaired pipe section where a local wall thinning is previously machined. For this test, the composite repair was designed according to ISO 24817. Then, a finite element model integrating damaged pipe and composite repair system is built. It allowed simulating the test, comparing the results with experiments and validating damage models implemented to capture the various possible types of failures. In addition, sensitivity analysis considering composite properties variations evidenced by experiments are run. The composite behavior considered in this study is not time dependent. No degradation of the composite material strength due to ageing is taking into account. The roadmap for the next steps of this work is to clearly identify the ageing mechanisms, to perform tests in relevant conditions and to introduce ageing effects in the design process (and in particular in the composite constitutive laws).

scholarly journals Effect of calcination temperature on silica-asphalt composite properties using amorphous rice husk silica

2021 ◽  
Vol 1751 ◽  
pp. 012071
Author(s):  
S. Sembiring ◽  
A. Riyanto ◽  
I. Firdaus ◽  
Junaidi ◽  
R. Situmeang
Keyword(s):  
Calcination Temperature ◽  
Rice Husk ◽  
Rice Husk Silica ◽  
Composite Properties

scholarly journals Repurposed/recycled discontinuous carbon fiber organosheet development and composite properties

2021 ◽  
Vol 4 ◽  
pp. 100092
Author(s):  
Philip R. Barnett ◽  
Colby L. Gilbert ◽  
Dayakar Penumadu
Keyword(s):  
Carbon Fiber ◽  
Composite Properties

scholarly journals Antibacterial Properties of Plasma-Activated Perfluorinated Substrates with Silver Nanoclusters Deposition

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 182
Author(s):  
Petr Slepička ◽  
Silvie Rimpelová ◽  
Nikola Slepičková Kasálková ◽  
Dominik Fajstavr ◽  
Petr Sajdl ◽  
...  
Keyword(s):  
Surface Properties ◽  
Antibacterial Properties ◽  
Argon Plasma ◽  
Antimicrobial Effect ◽  
Silver Nanoclusters ◽  
Plasma Modification ◽  
Material Surface ◽  
Silver Deposition ◽  
Force Microscopy ◽  
Atomic Force

This article is focused on the evaluation of surface properties of polytetrafluoroethylene (PTFE) nanotextile and a tetrafluoroethylene-perfluoro(alkoxy vinyl ether) (PFA) film and their surface activation with argon plasma treatment followed with silver nanoclusters deposition. Samples were subjected to plasma modification for a different time exposure, silver deposition for different time periods, or their combination. As an alternative approach, the foils were coated with poly-L-lactic acid (PLLA) and silver. The following methods were used to study the surface properties of the polymers: goniometry, atomic force microscopy, and X-ray photoelectron microscopy. By combining the aforementioned methods for material surface modification, substrates with antibacterial properties eliminating the growth of Gram-positive and Gram-negative bacteria were prepared. Studies of antimicrobial activity showed that PTFE plasma-modified samples coated with PLLA and deposited with a thin layer of Ag had a strong antimicrobial effect, which was also observed for the PFA material against the bacterial strain of S. aureus. Significant antibacterial effect against S. aureus, Proteus sp. and E. coli has been demonstrated on PTFE nanotextile plasma-treated for 240 s, coated with PLLA, and subsequently sputtered with thin Ag layer.

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