Experimental and Numerical Study of Basalt FRP Strip Strengthened RC Slabs under Impact Loads

2020 ◽  
Vol 20 (06) ◽  
pp. 2040001 ◽  
Author(s):  
Wensu Chen ◽  
Thong M. Pham ◽  
Mohamed Elchalakani ◽  
Huawei Li ◽  
Hong Hao ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Study ◽  
Impact Resistance ◽  
Basalt Fiber ◽  
Impact Behavior ◽  
Impact Loads ◽  
Quantitative Measurements ◽  
Rc Slabs ◽  
The Impact

Basalt fiber-reinforced polymer (BFRP) has been applied for strengthening concrete structures. However, studies on reinforced concrete (RC) slabs strengthened by BFRP strips under impact loads are limited in open literature. This study investigates the efficiency of using BFRP strips with various strengthening layouts and anchoring schemes on the impact resistance of RC slabs. A total of 11 two-way square slabs were prepared and tested, including one reference specimen without strengthening and ten slabs strengthened with BFRP strips and/or anchors. The RC slabs were impacted by a drop weight with increasing height until slab failure. The observed failure modes include punching shear failure, BFRP sheet debonding and reinforcement fracture. The failure modes and the effects of using various strengthening schemes on the impact resistant capacity of RC slabs were examined. The quantitative measurements, such as impact velocity, indentation depth and diameter, were compared and discussed. In addition, numerical studies were carried out by using LS-DYNA to simulate the impact tests of RC slabs with and without BFRP strengthening. With the calibrated numerical model, the impact behavior of slabs with various dimensions and strengthening layouts under different impact intensities can be predicted with good accuracy.

TRM Versus FRP as Strengthening Material for Improving Impact Resistance of RC Slabs

2016 ◽  
Author(s):  
Husain Abbas ◽  
Tarek Almusallam ◽  
Yousef Al-Salloum ◽  
Nadeem Siddiqui ◽  
Aref Abadel
Keyword(s):  
Experimental Testing ◽  
Impact Resistance ◽  
Single Layer ◽  
High Strength ◽  
Impact Loads ◽  
Local Damage ◽  
Cfrp Sheet ◽  
Ballistic Limit Velocity ◽  
Rc Slabs ◽  
The Impact

This study experimentally investigates the effectiveness of textile reinforced mortar (TRM) in controlling the local damage in reinforced concrete (RC) slabs subjected to impact loads. The results are then compared with that of conventional FRP strengthening of RC slabs. The impact tests were conducted using the strike of hemispherical nosed steel projectile on TRM- and FRP-strengthened RC slabs. The unstrengthened specimens considered as control were 600 mm square, 90 mm thick RC slabs. The slabs were reinforced with 8 mm diameter steel rebars at 100 mm c/c spacing both-ways. The slabs were strengthened by externally bonding single layer of Carbon FRP (CFRP) and two layers of TRM on the rear face of the slabs. In TRM strengthening, the textile contained equal quantity of high strength carbon fiber roved in two orthogonal directions. They were simply placed on the top of each other and bonded on a secondary polypropylene line. A commercial polymer modified cement mix was used as mortar in TRM strengthening. The velocity of 40 mm diameter steel projectile was varied within sub-ordinance range and the projectile was made to strike normal to the slab using a gas gun. Based on the experimental testing conducted in this study, it was observed that CFRP and TRM strengthening of RC slabs are effective in reducing the local damage in RC slabs from front and rear faces for the same impact velocity. Both TRM and CFRP strengthening cause increase in the ballistic limit velocity and the perforation energy of RC slabs. Moreover, the CFRP sheet and TRM layer considerably reduce the generation of secondary projectiles which are in the form of flying debris in un-strengthened RC slabs. Overall, among the two strengthening methods studied, the TRM strengthening of RC slabs is found to be either equally good or better than the CFRP strengthening in resisting impact loads.

Experimental Investigation on the Low-Velocity Impact Damage of 3D Angle-Interlock Woven Composites

2012 ◽  
Vol 487 ◽  
pp. 793-797 ◽  
Author(s):  
Li Juan Yu ◽  
Li Min Jin ◽  
Zhi Lin Niu ◽  
Bao Zhong Sun ◽  
Yi Zhu Zheng ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Woven Composites ◽  
Low Velocity ◽  
Plane Shear ◽  
Velocity Impact ◽  
The Impact

In this paper, the low-velocity impact behavior of the 3D angle-interlock woven glass-fiber/epoxy composites (3DAWCs) were tested and analyzed under several levels of impact energies. The energy-time curves, deflection-time curves and load-deflection curves were obtained to show the impact damage behavior. It was found that the damage magnitude increases with the impact energy, and the composite structure can effectively reduce the in-plane shear failure. In addition, the failure modes were also photographed to illustrate the damage mechanisms of the3DAWCs.

IMPACT RESISTANCE PROPERTIES OF KEVLAR/GLASS FIBER HYBRID COMPOSITE LAMINATES

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Norazean Shaari ◽  
Aidah Jumahat ◽  
M. Khafiz M. Razif
Keyword(s):  
Glass Fiber ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Impact Damage ◽  
Impact Resistance ◽  
Impact Behavior ◽  
Slight Reduction ◽  
Depth Of Penetration ◽  
Damage Degree ◽  
The Impact

In this paper, the impact behavior of Kevlar/glass fiber hybrid composite laminates was investigated by performing the drop weight impact test (ASTM D7136). Composite laminates were fabricated using vacuum bagging process with an epoxy matrix reinforced with twill Kevlar woven fiber and plain glass woven fiber. Four different types of composite laminates with different ratios of Kevlar to glass fiber (0:100, 20:80, 50:50 and 100:0) were manufactured. The effect of Kevlar/glass fiber content on the impact damage behavior was studied at 43J nominal impact energy. Results indicated that hybridization of Kevlar fiber to glass fiber improved the load carrying capability, energy absorbed and damage degree of composite laminates with a slight reduction in deflection. These results were further supported through the damage pattern analysis, depth of penetration and X-ray evaluation tests. Based on literature work, studies that have been done to investigate the impact behaviour of woven Kevlar/glass fiber hybrid composite laminates are very limited. Therefore, this research concentrates on the effect of Kevlar on the impact resistance properties of woven glass fibre reinforced polymer composites.

scholarly journals Numerical Study of Hydrodynamic Impact on Bubbly Water

2015 ◽  
Author(s):  
Mehdi Elhimer ◽  
Aboulghit El Malki Alaoui ◽  
Kilian Croci ◽  
Céline Gabillet ◽  
Nicolas Jacques
Keyword(s):  
Volume Fraction ◽  
Numerical Study ◽  
Numerical Data ◽  
Void Volume Fraction ◽  
Bubbly Liquid ◽  
Impact Loads ◽  
Hydrodynamic Impact ◽  
Physical Mechanisms ◽  
The Impact ◽  
The Relationship

The phenomenon of slamming on a bubbly liquid has many occurrences in marine and costal engineering. However, experimental or numerical data on the effect of the presence of gas bubbles within the liquid on the impact loads are scarce and the related physical mechanisms are poorly understood. The aim of the present paper is to study numerically the relationship between the void volume fraction and the impact loads. For that purpose, numerical simulations of the impact of a cone on bubbly water have been performed using the finite element code ABAQUS/Explicit. The present results show the diminution of the impact loads with the increase of the void fraction. This effect appears to be related to the high compressibility of the liquid-gas mixture.

Experimental and numerical study of the impact behavior of SMC plates

1999 ◽  
Vol 47 (1-4) ◽  
pp. 551-561 ◽  
Author(s):  
Sang-Min Lee ◽  
Jae-Seung Cheon ◽  
Yong-Taek Im
Keyword(s):  
Numerical Study ◽  
Impact Behavior ◽  
The Impact

Improving the Impact Resistance of Reinforced Concrete

2014 ◽  
Vol 919-921 ◽  
pp. 1924-1929 ◽  
Author(s):  
Husain Abbas ◽  
Tarek Almusallam ◽  
Yousef Al-Salloum
Keyword(s):  
Reinforced Concrete ◽  
Split Hopkinson Pressure Bar ◽  
Impact Resistance ◽  
Concrete Structures ◽  
Material Behavior ◽  
Analytical Models ◽  
Impact Loads ◽  
Hopkinson Pressure Bar ◽  
Hybrid Fibers ◽  
The Impact

The strategic concrete structures are often required to resist impact loads arising from the projectile strike, falling weight, blast generated missile etc. The existing structures found deficient in resisting these loads are required to be retrofitted whereas the upcoming structures are required to be designed for expected impact loads. This paper explores the ways of strengthening existing reinforced concrete (RC) structures using externally bonded carbon fiber reinforced polymer (CFRP) sheets and improving the impact resistance of concrete by mixing hybrid fibers in its production. The impact response of concrete structures is assessed using experiments involving the impact of projectiles of different nose shapes on slab specimens. The material behavior at high strain rate is established using split Hopkinson pressure bar (SHPB) testing at varying strain rates. Analytical models are developed for predicting penetration depth, scabbing thickness, ballistic limit velocity and ejected mass. The experimental results were also validated through numerical modeling using LS-DYNA.

scholarly journals Effect of Mold Temperature on the Impact Behavior and Morphology of Injection Molded Foams Based on Polypropylene Polyethylene–Octene Copolymer Blends

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 894 ◽  
Author(s):  
Santiago Muñoz-Pascual ◽  
Eduardo Lopez-Gonzalez ◽  
Cristina Saiz-Arroyo ◽  
Miguel Angel Rodriguez-Perez
Keyword(s):  
Impact Resistance ◽  
Mold Temperature ◽  
Impact Behavior ◽  
Critical Parameters ◽  
Crystalline Morphology ◽  
Copolymer Blends ◽  
Opposite Trend ◽  
Izod Impact ◽  
Injection Molded ◽  
The Impact

In this work, an isotactic polypropylene (PP) and a polyethylene–octene copolymer (POE) have been blended and injection-molded, obtaining solids and foamed samples with a relative density of 0.76. Different mold temperature and injection temperature were used. The Izod impact strength was measured. For solids, higher mold temperature increased the impact resistance, whereas in foams, the opposite trend was observed. In order to understand the reasons of this behavior, the morphology of the elastomeric phase, the crystalline morphology and the cellular structure have been studied. The presence of the elastomer near the skin in the case of high mold temperature can explain the improvement produced with a high mold temperature in solids. For foams, aspects as the elastomer coarsening in the core of the sample or the presence of a thicker solid skin are the critical parameters that justify the improved behavior of the materials produced with a lower mold temperature.

scholarly journals Failure Modes of a Reticulated Dome in a Small Airplane Crash

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
L. Lin ◽  
Y. X. Ren ◽  
M. Y. Huang ◽  
X. D. Zhi ◽  
D. Z. Wang
Keyword(s):  
Failure Modes ◽  
Impact Resistance ◽  
Test Subject ◽  
Engineering Research ◽  
Airplane Crash ◽  
Reticulated Domes ◽  
Small Airplanes ◽  
Span 60 ◽  
The Impact ◽  
Roof Sheathing

Since the 9/11 incident, many engineering research works have been conducted on the impact resistance of large-span space structures. In the present study, a small airplane, Bombardier Challenger 850, was chosen as the test subject. An airplane crash on a single-layered Kiewitt-8 reticulated dome with span 60 m considering roof sheathing effect was simulated using ANSYS/LS-DYNA software. The principles of establishing the numerical model of small airplanes were determined. In addition, the impact styles of small airplane and impact positions on the dome were investigated. The failure modes of reticulated dome with roof sheathing due to small airplane crash were identified. Furthermore, the failure modes between reticulated domes with and without roof sheathing were compared and the effect of roof sheathing on the failure modes of reticulated dome under a small airplane crash was investigated.

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