scholarly journals Mechanical Properties of GFRPs Exposed to Tensile, Compression and Tensile–Tensile Cyclic Tests

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 898
Author(s):  
Mariana Domnica Stanciu ◽  
Horațiu Teodorescu Drăghicescu ◽  
Ioan Călin Roșca

Currently there are many applications for the use of composites reinforced with fiberglass mat and fabrics with polyester resin: automotive, aerospace, construction of wind turbines blades, sanitary ware, furniture, etc. The structures made of composites have a complex geometry, can be simultaneously subjected to tensile–compression, shear, bending and torsion. In this paper we analyzed the mechanical properties of a polyester composite material reinforced with glass fiber (denoted GFRP) of which were carried out two types of samples: The former contains four layers of plain fabric (GFRP-RT500) and the second type contains three layers of chopped strand mat (GFRP-MAT450). The samples were subjected to tensile, compression and tensile–tensile cyclic loading. The results highlight the differences between the two types of GFRP in terms of initial elastic modulus, post yield stiffness and viscoelastic behavior under cyclic loading. Thus, it was observed that the value of the modulus of elasticity and the value of ultimate tensile stress are approximately twice higher in the case of GFRP-RT500 than for the composite reinforced with short fibers type GFRP-MAT450. The tensile–tensile cyclic test highlights that the short glass fiber-reinforced composite broke after the first stress cycle, compared to the fabric-reinforced composite in which rupture occurred after 15 stress cycles. The elasticity modulus of GFRP-RT500 decreased by 13% for the applied loading with the speed of 1 mm/min and by 15% for a loading speed of 20 mm/min.

Author(s):  
Lebogang Lebea ◽  
Harry M Ngwangwa ◽  
Dawood Desai ◽  
Fuluphelo Nemavhola

The initial stability after implantology is paramount to the survival of the dental implant and the surface roughness of the implant plays a vital role in this regard. The characterisation of surface topography is a complicated branch of metrology, with a huge range of parameters available. Each parameter contributes significantly towards the survival and mechanical properties of 3D-printed specimens. The purpose of this paper is to experimentally investigate the effect of surface roughness of 3D-printed dental implants and 3D-printed dogbone tensile samples under areal height (Ra) parameters, amplitude parameters (average of ordinates), skewness (Rsk) parameters and mechanical properties. During the experiment, roughness values were analysed and the results showed that the skewness parameter demonstrated a minimum value of 0.596%. The 3D-printed dental implant recorded Ra with a 3.4 mm diameter at 43.23% and the 3D-printed dental implant with a 4.3 mm diameter at 26.18%. Samples with a complex geometry exhibited a higher roughness surface, which was the greatest difficulty of additive manufacturing when evaluating surface finish. The results show that when the ultimate tensile stress (UTS) decreases from 968.35 MPa to 955.25 MPa, Ra increases by 1.4% and when UTS increases to 961.18 MPa, Ra increases by 0.6%. When the cycle decreases from 262142 to 137433, Ra shows that less than a 90.74% increase in cycle is obtained. For 3D-printed dental implants, the higher the surface roughness, the lower the mechanical properties, ultimately leading to decreased implant life and poor performance.


2018 ◽  
Vol 877 ◽  
pp. 50-53 ◽  
Author(s):  
Vinayashree ◽  
R. Shobha

Aluminium composites are in predominant use due to their lower weight and high strength among the MMC’s. Aluminium 6061 is selected as matrix and E-glass fiber is selected as reinforcement. Fabrication of composite is done by stir casting method. Each fabrication carries the E-glass reinforcement content varied from 2% to 10%. The present article attempts to evaluate the mechanical properties of E-glass fibre reinforced composite and study the effect of reinforcement on the matrix alloy through mechanical properties. When compared to ascast mechanical properties the UTS has increased from 74.28 N/sq mm to 146.8 N/sq mm for a composite at 6% E-glass. The hardness of as-cast has also increased from 22 RHB to 43 RHB at 6% E-glass and the wear of composite has exhibited a decreasing tend with increase in reinforcement content along the sliding distance. The results are analyzed in certain depth in the current paper. The mechanical properties of composites have improved with the increase in the weigh percentage of glass fiber in the aluminium matrix.


2013 ◽  
Vol 48 (24) ◽  
pp. 3025-3034 ◽  
Author(s):  
Ilias Mouallif ◽  
Abdelkhalek Latrach ◽  
M’hamed Chergui ◽  
Abdelkader Benali ◽  
Mohammed Elghorba ◽  
...  

2017 ◽  
Vol 7 (1.1) ◽  
pp. 78
Author(s):  
C. Thiruvasagam ◽  
S. Prabagaran ◽  
P. Suresh

The research paper involves fiber composites form a special category materials that are contributing to present swaping of manufactured  hybrid  which finds traditional and non traditional applications. The study explains which are accentuates and optimizing for the recently recognized snake grass standard materials. In this article, the prospecting performance characterization of SG fiber is selected and contrasted as per the ASTM standard. This study additionally manages the examination apply different phenomena of this stages in Jute and snake as fortifications utilized index ended a try. Experiments have been conducted on normal Filaments, snake grass, Glass Fiber and Jute to analyse their Mechanical properties. The common strands are orchestrated in the flat and vertical heading as transferred quality on all sides. Microstructural analysis of these hybrid composite is observed using Scanning  Electron Microscope that reveals bonding and Filament breaksge, Voids and Fiber decover which are further investigated.


2020 ◽  
Vol 978 ◽  
pp. 277-283
Author(s):  
Kishore Kumar Mahato ◽  
Krishna Chaitanya Nuli ◽  
Krishna Dutta ◽  
Rajesh Kumar Prusty ◽  
Bankim Chandra Ray

Fiber reinforced polymeric (FRP) composite materials are currently used in numerous structural and materials related applications. But, during their in-service period these composites were exposed to different changing environmental conditions. Present investigation is planned to explore the effect of thermal shock exposure on the mechanical properties of nanoTiO2 enhanced glass fiber reinforced polymeric (GFRP) composites. The samples were conditioned at +70°C temperature for 36 h followed by further conditioning at – 60°C temperature for the similar interval of time. In order to estimate the thermal shock influence on the mechanical properties, tensile tests of the conditioned samples were carried out at 1 mm/min loading rate. The polymer phase i.e. epoxy was modified with different nanoTiO2 content (i.e. 0.1, 0.3 and 0.5 wt. %). The tensile strength of 0.1 wt.% nanoTiO2 GFRP filled composites exhibited higher ultimate tensile strength (UTS) among all other composites. The possible reason may be attributed to the good dispersion of nanoparticles in polymer matrix corresponds to proper stress transfer during thermal shock conditioning. In order to access the variations in the viscoelastic behavior and glass transition temperature due to the addition of nanoTiO2 in GFRP composite and also due to the thermal shock conditioning, dynamic mechanical thermal analysis (DMTA) measurements were carried out. Different modes of failures and strengthening morphology in the composites were analyzed under scanning electron microscope (SEM).


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