Numerical prediction of damage mechanisms of E-Glass/epoxy composite material against ballistic impact of 7.62 MS projectile

2020 ◽  
pp. 204141962096702
Author(s):  
Venkata Ramudu Bodepati ◽  
Jayarami Reddy C ◽  
Madhu Vemuri
Keyword(s):  
Composite Material ◽  
Failure Modes ◽  
Epoxy Composite ◽  
Damage Mechanism ◽  
Ballistic Impact ◽  
Experimental Results ◽  
Analytical Models ◽  
Specific Strength ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

The fibre reinforced polymer matrix composite materials have acquired more credibility over other materials like metals and ceramics due to their high specific strength. Numerical simulations of ballistic impact of 7.62 mild steel projectile on various thicknesses of plain woven E-Glass/epoxy composite material were performed. Residual velocity and ballistic limit of the composite material were determined numerically and the results are compared with that of experiments published elsewhere. The numerical and experimental results are in good agreement. The numerical results are also compared with Recht-Ipson (R-I) and Gellert et al analytical models and are found to be in good correlation. Various failure mechanisms such as two stage damage mechanism namely dishing in target materials less than 10mm and indentation followed by dishing in target materials greater than 10 mm, delamination, and fibre and matrix failure modes of the composite material were studied and compared with the analytical models and experimental results. The wave propagation mechanisms and the damage phenomena are also studied and correlated.

scholarly journals Comparison of Analytical Approaches Predicting the Compressive Strength of Fibre Reinforced Polymers

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2517 ◽  
Author(s):  
Christian Leopold ◽  
Sergej Harder ◽  
Timo Philipkowski ◽  
Wilfried Liebig ◽  
Bodo Fiedler
Keyword(s):  
Compressive Strength ◽  
Prediction Accuracy ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Experimental Results ◽  
Analytical Models ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Analytical Approaches

Common analytical models to predict the unidirectional compressive strength of fibre reinforced polymers are analysed in terms of their accuracy. Several tests were performed to determine parameters for the models and the compressive strength of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP). The analytical models are validated for composites with glass and carbon fibres by using the same epoxy matrix system in order to examine whether different fibre types are taken into account. The variation in fibre diameter is smaller for CFRP. The experimental results show that CFRP has about 50% higher compressive strength than GFRP. The models exhibit significantly different results. In general, the analytical models are more precise for CFRP. Only one fibre kinking model’s prediction is in good agreement with the experimental results. This is in contrast to previous findings, where a combined modes model achieves the best prediction accuracy. However, in the original form, the combined modes model is not able to predict the compressive strength for GFRP and was adapted to address this issue. The fibre volume fraction is found to determine the dominating failure mechanisms under compression and thus has a high influence on the prediction accuracy of the various models.

scholarly journals Strengthening of Precast RC Frame to Mitigate Progressive Collapse by Externally Bonded CFRP Sheets Anchored with HFRP Anchors

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jianwu Pan ◽  
Xian Wang ◽  
Fang Wu
Keyword(s):  
Failure Modes ◽  
Progressive Collapse ◽  
Analytical Models ◽  
Strengthening Effect ◽  
Rc Frame ◽  
Concrete Frames ◽  
Catenary Action ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Currently, the robustness of precast reinforced concrete frames is attracting wide attention. However, avoiding “strong beams and weak columns” during strengthening against progressive collapse is a key problem. To discuss this problem, an experimental study on two 1/2-scale precast frame subassemblages under a pushdown loading regime was carried out in this paper. One specimen was strengthened with carbon fibre-reinforced polymer (CFRP) sheets on the beam sides. The middle parts of the CFRP sheets were anchored with hybrid fibre-reinforced polymer (HFRP) anchors. Another specimen was not strengthened. The failure mechanisms, failure modes, and strengthening effect are discussed. The strengthening effect is very obvious in the early catenary action stage. No shearing failure develops on HFRP anchors, which proves that the anchoring method is effective. Based on the experimental results, analytical models and preventive strengthening design and construction measures to mitigate progressive collapse of the precast RC frame are proposed.

scholarly journals Strengthening of Hollow Square Sections under Compression Using FRP Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
M. C. Sundarraja ◽  
P. Sriram ◽  
G. Ganesh Prabhu
Keyword(s):  
Failure Modes ◽  
Deformation Behaviour ◽  
Three Dimensional ◽  
Local Buckling ◽  
Experimental Results ◽  
Frp Composites ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

The feasibility study on carbon fibre reinforced polymer (CFRP) fabrics in axial strengthening of hollow square sections (HSS) was investigated in this paper. CFRP was used as strips form with other parameters such as the number of layers and spacing of strips. Experimental results revealed that the external bonding of normal modulus CFRP strips significantly enhanced the load carrying capacity and stiffness of the hollow sections and also reduced the axial shortening of columns by providing external confinement against the elastic deformation. The increase in the CFRP strips thickness effectively delayed the local buckling of the above members and led to the inward buckling rather than outward one. Finally, three-dimensional nonlinear finite element modeling of CFRP strengthened hollow square sectionswas created by using ANSYS 12.0 to validate the results and the numerical results such as failure modes and load deformation behaviour fairly agreed with the experimental results.

scholarly journals EFFECT OF USING EXTERNAL GFRP PLATES ON STRUCTURALLY DEFICIENT RC BEAMS

2003 ◽  
Vol 9 (1) ◽  
pp. 36-44
Author(s):  
Hau Y. Leung ◽  
Ramapillai V. Balendran
Keyword(s):  
Failure Modes ◽  
Experimental Results ◽  
Deformation Capacity ◽  
Rc Beams ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Strength And Deformation

This paper presents some experimental results on the behaviour of flexure- and shear-deficient RC beams strengthened with external glass fibre reinforced polymer (GFRP) plates. Ten number of 2,5 m long over-designed, unplated under-design and plated under-designed beams were examined under four-point bending condition. Experimental results indicated that use of GFRP plates enhanced the strength and deformation capacity of the structurally deficient beams by altering their failure modes. Application of side plates on shear-deficient RC beams appeared to be more effective than using bottom plates on flexure-deficient RC beams. However, without any improvement on concrete compressive capacity, additional shear capacities provided to the beams under the action of side plates increased the likelihood of beam failure by concrete crushing. Simultaneous use of bottom and side plates on flexure- and shear-deficient RC beams could result in reduced deflection. The change in the neutral axis depth and GFRP strain was also addressed.

Durability of coral-reef-sand concrete beams reinforced with basalt fibre-reinforced polymer bars in seawater

2021 ◽  
pp. 136943322098166
Author(s):  
Wang Xin ◽  
Shi Jianzhe ◽  
Ding Lining ◽  
Jin Yundong ◽  
Wu Zhishen
Keyword(s):  
Coral Reef ◽  
Marine Environment ◽  
Failure Modes ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Basalt Fibre ◽  
Rc Structures ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

A combination of coral reef sand (CRS) concrete and fibre-reinforced polymer (FRP) bars provides an effective solution to the durability deficiency in conventional RC structures. This study experimentally investigates the durability of CRS concrete beams reinforced with basalt FRP (BFRP) bars in a simulated marine environment. Flexural tests are conducted on a total of fourteen CRS concrete beams aged in a cyclic wet-dry saline solution at temperatures of 25, 40 and 55°C. The variables comprise the types of reinforcement (steel and BFRP), the aging duration and the temperature. The failure modes, capacities, deflections and crack development of the beams are analysed and discussed. The results indicate that the ultimate load of the beams exhibits no degradation after aging, whereas the failure mode of the BFRP-CRS concrete beams transition from flexure to shear, which is caused by the degradation in the mechanical properties of the stirrups. The aged BFRP-CRS concrete beams show a substantial increase of over 70% in their initial stiffness compared with the control beams (beams without aging) and a substantial decrease in their crack width after aging due to the prolonged maturation of the concrete. Furthermore, a formula for calculating the shear capacity in the existing code is modified by a partial factor equal to 2, which can predict the capacity of a CRS concrete beam reinforced with BFRP bars in a marine environment.

Reliability of damage mechanism localisation by acoustic emission on glass/epoxy composite material plate

2012 ◽  
Vol 94 (5) ◽  
pp. 1483-1494 ◽  
Author(s):  
Salah-Eddine Mechraoui ◽  
Abdelouahed Laksimi ◽  
Salim Benmedakhene
Keyword(s):  
Acoustic Emission ◽  
Composite Material ◽  
Epoxy Composite ◽  
Damage Mechanism

scholarly journals High Velocity Impact Test on Glass Fibre Reinforced Polymer (GFRP) Using a Single Stage Gas Gun (SSGG) - An Experimental Based Approach

2014 ◽  
Vol 564 ◽  
pp. 376-381 ◽  
Author(s):  
N. Razali ◽  
Mohamed Thariq Hameed Sultan ◽  
S.N.A. Safri ◽  
Shahnor Basri ◽  
Noorfaizal Yidris ◽  
...  
Keyword(s):  
Composite Material ◽  
Impact Test ◽  
Impact Force ◽  
Specimen Thickness ◽  
Gas Gun ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
The Impact

The aim of this work is to study the effect of thickness and type of bullet in impact test on structures made from a composite material. The composite material used in this study was Glass Fibre Reinforced Polymer (GFRP). This material was fabricated to produce laminated plate specimens with dimension of 100 mm × 100 mm and 6, 8, 10, and 12 mm thickness. The impact test was performed using a Single Stage Gas Gun (SSGG) with blunt, hemispherical, and conical types of bullets. The gas gun pressure was set to 5, 10, 15 and 20 bar. In the tests, gas gun pressure, bullet type and specimen thickness were varied to ascertain the influence of these parameters on the materials response. The relation between impact force with gas pressure, type of bullets and specimens thickness are presented and discussed. The best thickness for GFRP was identified according to the impact results. From the impact tests conducted, it was found that at the same amount of pressure, the higher the thickness, the bigger the impact force because as the specimen thickness increases, the amount of impact force absorbed by the specimen is higher.

scholarly journals Behavior of Hybrid CFRP Laminated Thin-Walled Beams: Experimental, Numerical, and Analytical Evaluations

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
A. M. Yosri ◽  
Gouda M. Ghanem ◽  
Mohamed A. E. Salama ◽  
Majed Alzara ◽  
Mohamed A. Farouk ◽  
...  
Keyword(s):  
Experimental Results ◽  
Fiber Reinforced Polymer ◽  
Core Material ◽  
Steel Beams ◽  
Specific Strength ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Hybrid Beams ◽  
Thin Walled ◽  
Strength And Stiffness

The aim of this paper is to assess the structural behavior of hybrid thin-walled beams which were fabricated using laminated carbon fiber reinforced polymer (CFRP). Seven hybrid (CFRP) I-beams were fabricated, instrumented, then have been tested under monotonic four-point loading in order to evaluate their behavior up to failure. In constructing the I-beam specimens which were evaluated in this study, plywood core was implemented on both the web and flanges. Several important parameters were conducted in this study considering changing both of the ply orientations and stacking sequences of laminated fibers, also changing the shear span-to-depth ratio (a/d) of the specimens. The experimental results showed that stacking sequence is the most significant parameter that influences both flexural strength and stiffness of the hybrid beams. Also, the experimental results promoted the effectiveness of the core material for enhancing the flexure (bending) stiffness of beams. Then, these results were compared with a previous simulated study which used the finite element modeling to model the beams. Also, in order to evaluate the efficiency of the CRFP beams, the results were compared to similar steel beams having the same dimensions of the CFRP beams. As compared to steel beams, the load carrying capacity of the laminated beams is being high compared with steel beams when taking into consideration their specific strength ratio.

Green Composites for Potential Substitution of E-Glass Composites and Plastics

2018 ◽  
pp. 187-204
Keyword(s):  
Natural Fiber ◽  
Epoxy Composite ◽  
Thermoplastic Composite ◽  
Fiber Reinforced Polymer ◽  
Green Composites ◽  
Glass Composites ◽  
Specific Strength ◽  
Reinforced Polymer ◽  
Specific Modulus ◽  
Weave Fabric

This chapter provides a comparative study of the mechanical properties for different natural fiber composites. These composites consist of natural fiber 8-harness stain weave fabric reinforcing an epoxy matrix. The analytical model discussed in Chapter 5 is used to evaluate the elastic and ultimate strengths properties. The comparison is made according to the calculated specific modulus and specific strength. The Natural Fiber Reinforced Polymer (NFRP) composites are compared together according to their categories and yet compared to a similar E-glass/epoxy composite. In addition, a polypropylene and a thermoplastic composite are used also as reference materials. It is shown that some NFRP especially those belonging to the Bast and Leaf categories provide better properties than the plastics and also the E-glass/epoxy composite. Overall the Flax/epoxy composite could be considered the optimum choice in terms of properties since it has high specific modulus and strength.

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