scholarly journals A Comparison between Interlaminar and In-plane Shear Strength of Unidirectional Glass Fibre-epoxy

1994 ◽  
Vol 3 (2) ◽  
pp. 096369359400300 ◽  
Author(s):  
Michael R. Wisnom ◽  
M. I. Jones

Short beam shear tests have been carried out on square cross-section specimens cut from a 32 ply plate. By rotating the beams through 90° both interlaminar and in-plane strength can be measured with identical specimens. The in-plane shear strength was found to be at least 10% higher than the interlaminar strength.

2018 ◽  
Vol 5 (4) ◽  
pp. 603-613
Author(s):  
M. Rajanish ◽  
◽  
N. V. Nanjundaradhya ◽  
Ramesh S. Sharma ◽  
H. K. Shivananda ◽  
...  

AIAA Journal ◽  
2002 ◽  
Vol 40 (11) ◽  
pp. 2368-2370
Author(s):  
Kunigal Shivakumar ◽  
Felix Abali ◽  
Adrian Pora

2020 ◽  
Vol 55 (1) ◽  
pp. 27-38
Author(s):  
Yasuka Nassho ◽  
Kazuaki Sanada

The purpose of this study is to improve interlaminar shear strength and self-healing efficiency of spread carbon fiber (SCF)/epoxy (EP) laminates containing microcapsules. Microencapsulated healing agents were embedded within the laminates to impart a self-healing functionality. Self-healing was demonstrated on short beam shear specimens, and the healing efficiency was evaluated by strain energies of virgin and healed specimens. The effects of microcapsule concentration and diameter on apparent interlaminar shear strength and healing efficiency were discussed. Moreover, damaged areas after short beam shear tests were examined by an optical microscope to investigate the relation between the microstructure and the healing efficiency of the laminates. The results showed that the stiffness and the apparent interlaminar shear strength of the laminates increased as the microcapsule concentration and diameter decreased. However, the healing efficiency decreased with decreasing the microcapsule concentration and diameter.


Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1188 ◽  
Author(s):  
Zvonek ◽  
Sirjovova ◽  
Branecky ◽  
Plichta ◽  
Skacel ◽  
...  

All reinforcements for polymer-matrix composites must be coated with a suitable material in the form of a thin film to improve compatibility and interfacial adhesion between the reinforcement and the polymer matrix. In this study, plasma nanotechnology was used to synthetize such functional nanocoatings using pure tetravinylsilane (TVS) and its mixtures with oxygen gas (O2) as precursors. The plasma-coated glass fibers (GFs) were unidirectionally embedded in a polyester resin to produce short composite beams that were analyzed by a short-beam-shear test to determine the shear strength characterizing the functionality of the nanocoatings in a GF/polyester composite. The developed plasma nanocoatings allowed controlling the shear strength between 26.2–44.1 MPa depending on deposition conditions, i.e., the radiofrequency (RF) power and the oxygen fraction in the TVS/O2 mixture. This range of shear strength appears to be sufficiently broad to be used in the design of composites.


2020 ◽  
pp. 002199832094893
Author(s):  
Gayatri Vineela Marrivada ◽  
Phaneendra Kiran Chaganti ◽  
Ravindran Sujith

The aim of this research work is to study the mechanical behaviour of dry triaxially braided glass fibre sleeves and its composites experimentally and analytically. The braided glass fibre sleeves for three angles 30°, 45° and 60° were fabricated on a modified maypole vertical braider following a regular braid architecture. Tensile, flexural, short beam shear and impact tests were performed to evaluate the mechanical properties of the composites. A numerical model was developed, which can be used to find the elastic properties and mechanical strength values of the dry braided fabric and its composites. It was observed that the tensile, flexural and interlaminar properties of 30° specimens were more compared to 45° and 60°. The difference between the estimated and experimental values were found to be an average of 8% for tensile moduli and 24% for the tensile strength.


2020 ◽  
pp. 096739112096845
Author(s):  
Ana Carolina Mendes Quintanilha Silva Santos ◽  
Francisco Maciel Monticeli ◽  
Heitor Ornaghi ◽  
Luis Felipe de Paula Santos ◽  
Maria Odila Hilário Cioffi

This work has been developed for a comparative purpose concerning the processing and respective mechanical performance of CFRP composites processed by resin transfer molding (RTM) and compression molding (CM) techniques. Thermal and viscosimetric tests before processing certified the optimal parameter procedure. Both composites were submitted to short-beam shear tests and through microscopy to determine failure mechanisms. CM specimens presented a decrease of 27% in shear strength caused by the presence of macro porosity that induced crack initiation and connection of different delamination plies, causing the speeding up of crack propagation and jump of the interlaminar layer. The low capillary effect and higher viscous force were responsible for macro porosity, inducing heterogeneous impregnation in CM and to the direction reduce in mechanical behavior. On the other hand, more homogeneous impregnation in RTM specimens was responsible for the absence of macro porosity, ensuring higher values of shear strength and lower void volume fraction.


1985 ◽  
Vol 22 (1) ◽  
pp. 136-142 ◽  
Author(s):  
F. S. Shuri ◽  
D. D. Driscoll ◽  
S. J. Garner

Two large-scale in situ shear tests were conducted at a damsite in western Canada. The rock at the site is a Cretaceous shale containing a thin clay seam tentatively identified as a bedding-plane shear zone. The material in this seam is significantly weaker than the intact rock and influences the design of certain features of the dam and structures. In order to provide shear strength data for design, two large blocks of shale were sheared along the clay seam. These tests differed from conventional in situ shear tests in two significant ways: the rate of shear displacement was strictly controlled, and pore pressures (both positive and negative) in the shear zone were carefully monitored throughout the test. This note presents the material properties of the shear zone, describes the test equipment and techniques, and discusses the results obtained. Key words: shear strength, in situ testing, pore pressure, shale.


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