In-Plane Shake-Table Testing of GFRP-Strengthened Concrete Masonry Walls

2007 ◽  
Vol 23 (1) ◽  
pp. 223-237 ◽  
Author(s):  
Martin Turek ◽  
Carlos E. Ventura ◽  
Steven Kuan
Keyword(s):  
Failure Modes ◽  
Concrete Block ◽  
Masonry Walls ◽  
Shake Table ◽  
Shake Table Tests ◽  
Glass Fiber Reinforced Plastic ◽  
Earthquake Records ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Ultimate Failure

In-plane shake-table tests were performed on eight full-scale unreinforced concrete block walls. Three of the walls were left as plain unreinforced masonry and five were strengthened using glass-fiber-reinforced plastic (GFRP) strips in four different configurations. All walls were first subjected to design-level earthquake records to determine the improvement obtained from the addition of the GFRP. The walls were then subjected to extreme-level earthquake records to examine the ultimate failure modes and the effects of the various GFRP configurations on the response of the walls. It was observed that all strengthened specimens performed well during the design-level shaking, and three of the four GFRP configurations also performed well during the extreme-level shaking. The tests showed that the use of vertical GFRP strips alone is able to improve the in-plane performance of URM walls. The strips were also able to control the failure modes, and prevent collapse after severe damage, improving significantly the life safety performance of URM walls.

Experimental study on shear performance of improved high-performance polymer cement mortar–glass fiber reinforced plastic reinforced masonry wall

2021 ◽  
pp. 136943322110463
Author(s):  
Jinli Qiao ◽  
Bo Liu ◽  
Yanyan Li ◽  
Shengyue Li ◽  
Wenbin Zhang
Keyword(s):  
Shear Strength ◽  
Failure Mode ◽  
High Performance ◽  
Failure Modes ◽  
Ductile Failure ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Glass Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic

The improved high-performance polymer cement mortar (PCM) and glass fiber reinforced plastic (GFRP) system reinforcement was used in the research to strengthen and repair the masonry structure, so as to improve its bond stress, anchoring force, and integral performance without changing the original structure and further study the shear performance of masonry structure strengthened by the combination of the two. The optimum ratio of improved high-performance PCM was determined by analyzing the bend-press ratio of PCM test block. Improved high-performance PCM and GFRP were combined to strengthen the damaged masonry wall, and a five-piece masonry wall composed of “improved high-performance PCM+ with or without GFRP+ different original wall failure modes before reinforcement” was designed. Through diagonal loading shear test, the shear strength, vertical displacement, horizontal relative displacement, and failure models of masonry walls were obtained, and the effects of five different reinforcement methods and different materials on shear strength, stiffness, ductility, and failure modes of masonry walls were studied. The results show that compared with the unreinforced original wall, the shear strength of the masonry wall reinforced with the improved O4PCM is 43.5% higher, and its stiffness is also greatly improved, but the failure mode is still brittle failure; the shear strength of masonry walls strengthened by O4PCM and GFRP is 6.5% higher than that of masonry walls strengthened by O4PCM alone, and the stiffness is also increased. Its failure mode changes from brittle failure to ductile failure; with a failure mode of ductile failure, the shear strength of masonry walls strengthened by P4PCM and GFRP and that strengthened by P6PCM and GFRP are 4.8% and 12.7% higher than that strengthened by O4PCM and GFRP, respectively, and the stiffness is also increased compared with that strengthened by O4PCM and GFRP. After experimental comparison, it is the best scheme to strengthen masonry wall with improved P6PCM and GFRP.

A STUDY ON THE PUSHOVER TEST AND NUMERICAL ANALYSIS OF GFRP FRAMES

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Yeou-Fong Li ◽  
Bo-Shiang Wang ◽  
Jian-Yu Lai
Keyword(s):  
Numerical Analysis ◽  
Failure Modes ◽  
Pushover Analysis ◽  
Analysis Software ◽  
Braced Frame ◽  
Glass Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Gfrp Composite ◽  
Column Joint

This paper presents the use of glass fiber reinforced plastic (GFRP) composite material to produce a structure frame; the behaviors of the GFRP frames were analyzed by using pushover test and a numerical analysis software. Double-web FRP I-beams are used for the beams and columns of the frame, and joints made from metal and FRP. Three types of frame specimens were involved: an un-braced frame, a compression-braced frame and a tension-braced frame for each joint type. The joints were bonded to the frame components using epoxy resin but also adding bolts in the beam-column joint. The pushover test was used to investigate the mechanical behaviors and failure modes of the GFRP frames. The analysis software SAP2000 was used for the pushover analysis of the GFRP frames, and it was shown that the ultimate strength and force-displacement relationships of the analytical results were similar to that of the experimental ones.

Comparison of Failure Modes of Piping Systems With Wall Thinning Subjected to In-Plane, Out-of-Plane, and Mixed Mode Bending Under Seismic Load: An Experimental Approach

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Izumi Nakamura ◽  
Akihito Otani ◽  
Masaki Shiratori
Keyword(s):  
Dynamic Behavior ◽  
Failure Modes ◽  
Seismic Load ◽  
Piping System ◽  
Shake Table ◽  
Shake Table Tests ◽  
Wall Thinning ◽  
Piping Systems ◽  
Out Of Plane ◽  
Plane Bending

Pressurized piping systems used for an extended period may develop degradations such as wall thinning or cracks due to aging. It is important to estimate the effects of degradation on the dynamic behavior and to ascertain the failure modes and remaining strength of the piping systems with degradation through experiments and analyses to ensure the seismic safety of degraded piping systems under destructive seismic events. In order to investigate the influence of degradation on the dynamic behavior and failure modes of piping systems with local wall thinning, shake table tests using 3D piping system models were conducted. About 50% full circumferential wall thinning at elbows was considered in the test. Three types of models were used in the shake table tests. The difference of the models was the applied bending direction to the thinned-wall elbow. The bending direction considered in the tests was either of the in-plane bending, out-of-plane bending, or mixed bending of the in-plane and out-of-plane. These models were excited under the same input acceleration until failure occurred. Through these tests, the vibration characteristic and failure modes of the piping models with wall thinning under seismic load were obtained. The test results showed that the out-of-plane bending is not significant for a sound elbow, but should be considered for a thinned-wall elbow, because the life of the piping models with wall thinning subjected to out-of-plane bending may reduce significantly.

The Importance of Material Structure in the Laser Cutting of Glass Fiber Reinforced Plastic Composites

1995 ◽  
Vol 117 (1) ◽  
pp. 133-138 ◽  
Author(s):  
G. Caprino ◽  
V. Tagliaferri ◽  
L. Covelli
Keyword(s):  
Experimental Data ◽  
Glass Fiber ◽  
Laser Cutting ◽  
Material Structure ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic

A previously proposed micromechanical formula, aiming to predict the vaporization energy Qv of composite materials as a function of fiber and matrix properties and fiber volume ratio, was assessed. The experimental data, obtained on glass fiber reinforced plastic panels with different fiber contents cut by a medium power CO2 cw laser, were treated according to a procedure previously suggested, in order to evaluate Qv. An excellent agreement was found between experimental and theoretical Qv values. Theory was then used to predict the response to laser cutting of a composite material with a fiber content varying along the thickness. The theoretical predictions indicated that, in this case, the interpretation of the experimental results may be misleading, bringing to errors in the evaluation of the material thermal properties, or in the prediction of the kerf depth. Some experimental data were obtained, confirming the theoretical findings.

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