Investigation of the bond behavior of flax FRP strengthened RC structures through double lap shear testing

In recent years, steel reinforced polymer (SRP) composites have emerged as a new technology for structural strengthening, and several researches have validated the effectiveness of SRP for masonry strengthening. Research has been carried out to study the bond behavior of SRP composites applied to a masonry substrate. However, how the moist and salt on masonry surface will affect bond, which is the weak link in real strengthening applications, is little known yet. This study aims at investigating the bond behavior of SRP composites applied to moist and salt-laden masonry blocks that were subjected to an artificial weathering protocol. Single-lap shear tests were conducted to determine the bond behavior, while ion chromatography provided the salts distribution of weathered specimens to interpret some results of the shear tests.

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Three Dimensional, Linear and Nonlinear Finite Element Modeling of FRP to Concrete Pull-Off Test

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.147.92 ◽

2011 ◽

Vol 147 ◽

pp. 92-98

Author(s):

Majid Noori Hamedani

Keyword(s):

Finite Element ◽

Stress Distribution ◽

Three Dimensional ◽

Nonlinear Finite Element ◽

Rc Structures ◽

Bond Behavior ◽

3 Dimensional ◽

Reinforced Polymer ◽

Concrete Layer ◽

Set Up

External bonding of fiber reinforced polymer (FRP) sheets to concrete is a popular method of strengthening reinforced concrete (RC) structures. A simple test was set-up in order to simulate the process of debonding in this type of strengthening. The set-up is simulating the bond behavior of strengthened RC structures. In the recent researches it was found out that bond behavior and actual stress distribution is a 3 dimensional phenomenon. This paper is presenting more details about pull-off tests by applying 3-D and nonlinear finite element models. As a first step linear model has been generated to show general stress distribution in the test, in a second step nonlinear model is implemented in order to predict the behavior of pull-off tests more accurately. Tests have shown that at ultimate load, deboning occurs within a concrete layer near the bond surface. Therefore, the paper is focusing on using a more realistic concretebehavior in the model.

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Deformation analysis of lap-shear testing of solder joints

Acta Materialia ◽

10.1016/j.actamat.2005.02.024 ◽

2005 ◽

Vol 53 (9) ◽

pp. 2633-2642 ◽

Cited By ~ 67

Author(s):

Y.-L. Shen ◽

N. Chawla ◽

E.S. Ege ◽

X. Deng

Keyword(s):

Solder Joints ◽

Deformation Analysis ◽

Shear Testing ◽

Lap Shear

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Application of Acoustic Emission Technique for Bond Characterization in FRP-Masonry Systems

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.624.534 ◽

2014 ◽

Vol 624 ◽

pp. 534-541 ◽

Cited By ~ 1

Author(s):

Bahman Ghiassi ◽

Els Verstrynge ◽

Paulo B. Lourenço ◽

Daniel V. Oliveira

Keyword(s):

Acoustic Emission ◽

Failure Mode ◽

Failure Modes ◽

Clear Distinction ◽

Acoustic Emission Technique ◽

Emission Data ◽

Bond Behavior ◽

Damage Propagation ◽

Lap Shear ◽

Bond Tests

The acoustic emission (AE) technique is used for investigating the interfacial fracture and damage propagation in GFRP-and SRG-strengthened bricks during debonding tests. The bond behavior is investigated through single-lap shear bond tests and the fracture progress during the tests is recorded by means of AE sensors. The fracture progress and active debonding mechanisms are characterized in both specimen types with the aim of AE outputs. Moreover, a clear distinction between the AE outputs of specimens with different failure modes, in both SRG-and GFRP-strengthened specimens, is found which allows characterizing the debonding failure mode based on acoustic emission data.

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Ultrasonic Welding of Glass Fiber Reinforced Polypropylene

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.557-559.1313 ◽

2012 ◽

Vol 557-559 ◽

pp. 1313-1316

Author(s):

Jian Guang Zhang ◽

Krishan.K. Chawla ◽

Uday.K. Vaidya

Keyword(s):

Glass Fiber ◽

Ultrasonic Welding ◽

Maximum Strength ◽

Weld Strength ◽

Fiber Reinforced ◽

Shear Testing ◽

Polypropylene Composites ◽

Lap Shear ◽

Glass Fiber Reinforced ◽

Weld Time

Glass fiber reinforced polypropylene composites were joined by ultrasonic welding, employing various weld conditions. Single-lap shear testing was used to evaluate the effect of weld time and weld pressure on the weld performance. The weld strength increased with increasing weld time and weld pressure until a plateau or maximum strength was reached. The required weld time to obtain a complete weld became shorter when the weld pressure was increased. As lower weld pressure was applied, a complete weld could not be obtained unless relatively longer weld times were employed. A welding map, showing conditions of weld time and weld pressure to get a good weld, was obtained.

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