Identification of Shear Properties for Woven Fiber Reinforced Polymer Simulation

2016 ◽  
Author(s):  
Dongyang Yang ◽  
Benoit Stalin ◽  
Yong Xia ◽  
Qing Zhou
Keyword(s):  
Strain Field ◽  
Compressive Strain ◽  
Strain Curve ◽  
Image Correlation ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Shear Tests ◽  
Shear Properties ◽  
Polymer Simulation ◽  
Reinforced Polymer

Finite element simulation of composite materials is still challenging as anisotropy of the material brings difficulty in accurately identifying shear properties for modeling. In this study, ±45° tensile tests, Iosipescu shear tests, rail shear tests and Arcan shear tests are conducted to obtain the engineering shear stress-strain curve of woven fiber reinforced polymer. Digital image correlation method is adopted to obtain the strain field of the specimens. It is indicated that Iosipescu shear tests introduce a strain field close to pure shear state while the other three test types introduce relatively large tensile strain or compressive strain. Shear properties obtained from Iosipescu tests are used to calibrate an extensively used composite material model, Matzenmiller-Lubliner-Taylor (MLT) model. The calibrated MLT model is then verified by simulating Arcan tests with different loading angles. The simulations indicate that MLT model gives reliable predictions on Arcan tests with smaller loading angles, while it overestimates the force-displacement responses at larger loading angles.

Behavior and modeling of post-heated circular concrete specimens repaired with fiber-reinforced polymer composites

2021 ◽  
pp. 136943322110585
Author(s):  
Seyed Mehrdad Elhamnike ◽  
Rasoul Abbaszadeh ◽  
Vahid Razavinasab ◽  
Hadi Ziaadiny
Keyword(s):  
Strain Curve ◽  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Concrete Members ◽  
Frp Composites ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites

Exposure of buildings to fire is one of the unexpected events during the life of the structure. The heat from the fire can reduce the strength of structural members, and these damaged members need to be strengthened. Repair and strengthening of concrete members by fiber-reinforced polymer (FRP) composites has been one of the most popular methods in recent years and can be used in fire-damaged concrete members. In this paper, in order to provide further data and information about the behavior of post-heated circular concrete columns confined with FRP composites, 30 cylindrical concrete specimens were prepared and subjected under four exposure temperatures of 300, 500, 700, and 900. Then, specimens were repaired by carbon fiber reinforced polymer composites and tested under axial compression. Results indicate that heating causes the color change, cracks, and weight loss of concrete. Also, with the increase of heating temperature, the shape of stress–strain curve of FRP-retrofitted specimens will change. Therefore, the main parts of the stress–strain curve such as ultimate stress and strain and the elastic modulus will change. Thus, a new stress–strain model is proposed for post-heated circular concrete columns confined by FRP composites. Results indicate that the proposed model is in a good agreement with the experimental data.

Development of Creep Test Method for Thermoplastic Fiber-Reinforced Polymer Composite Tubes Under Pure Hoop Loading Condition

2019 ◽  
Author(s):  
Hai G. M. Doan ◽  
Hossein Ashrafizadeh ◽  
Pierre Mertiny
Keyword(s):  
Creep Behavior ◽  
Axial Loading ◽  
Test Method ◽  
Image Correlation ◽  
Fiber Reinforced Polymer ◽  
Time Dependent ◽  
Loading Conditions ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Dependent Behavior

Abstract Piping made from thermoplastic fiber reinforced polymer composites (TP-FRPCs) is receiving increasing attention in the oil and gas industry. Creep and time-dependent behavior is one of the main factors defining the service life of TP-FRPC structures. The lifetime and time-dependent behavior of TP-FRPC structures can be predicted using simulation tools, such as finite element analysis, to aid in the design optimization by modeling the long-term behavior of the material. Composite material time-dependent properties are required inputs for such models. While there is previous research available on creep testing of TP-FRPCs in laminate geometry, such tests may not enable accurate determination of the composite properties due to edge effects. On the other hand, coupons with tubular geometry not only provide improved load distribution between the fibers and matrix with minimal end effects, they also enable certain loading conditions experienced during typical piping operations such as internal pressure. In this study, a testing method to capture the creep behavior of tubular TP-FRPC specimens subjected to multi-axial loading conditions was developed. Tubular coupons were prototyped by an automated tape placement process. Strain was measure using digital image correlation technique and strain gauges. The development of the test setup forms the foundation for further testing of tubular TP-FRPC coupons at different multi-axial loading conditions. As a preliminary test, the creep behavior of a TP-FRPC tube subjected to pure hoop stress condition was evaluated using the developed testing process.

scholarly journals Creep Testing of Thermoplastic Fiber-Reinforced Polymer Composite Tubular Coupons

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4637 ◽  
Author(s):  
Hai Giang Minh Doan ◽  
Pierre Mertiny
Keyword(s):  
Creep Testing ◽  
Image Correlation ◽  
Fiber Reinforced Polymer ◽  
Ductile Material ◽  
Fiber Reinforced ◽  
Dimensional Changes ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Research Findings ◽  
Axial Compressive Stress

Thermoplastic fiber-reinforced polymer composites (TP-FRPC) are gaining popularity in industry owing to characteristics such as fast part fabrication, ductile material properties and high resistance to environmental degradation. However, TP-FRPC are prone to time-dependent deformation effects like creep under sustained loading, which can lead to significant dimensional changes and affect the safe operation of structures. Previous research in this context has focused, mainly, on testing of flat coupons. In this study, a creep testing method for TP-FRPC tubular coupons was developed. Specimens were fabricated using tape winding and subjected to well-defined loading conditions, i.e., pure hoop tensile and pure axial compressive stress. Strain gauges and digital image correlation were both employed for strain measurements and were found to be in good agreement. The evolution of strain rate, Poisson’s ratio and creep compliance were investigated. The prediction of experimental data by the Burgers model and the Findley’s power law model were explored. The research findings suggest that the developed experimental and analysis approach provides valuable information for the design of material systems and structures.

scholarly journals Short-Term Analysis of Adhesive Types and Bonding Mistakes on Bonded-in-Rod (BiR) Connections for Timber Structures

2021 ◽  
Vol 11 (6) ◽  
pp. 2665
Author(s):  
Jure Barbalić ◽  
Vlatka Rajčić ◽  
Chiara Bedon ◽  
Michal K. Budzik
Keyword(s):  
Fracture Mechanics ◽  
Design Procedure ◽  
Image Correlation ◽  
Fiber Reinforced Polymer ◽  
Special Focus ◽  
Timber Structures ◽  
Fiber Reinforced ◽  
Pull Out ◽  
Reinforced Polymer ◽  
The Impact

Bonded-in rods (BiR) represent a structural connection type that is largely used for new timber structures and rehabilitation (repair or reinforcement) of existing structural members. The technology is based on steel / Fiber Reinforced Polymer (FRP) / Glass Fiber Reinforced Polymer (GFRP) rods bonded into predrilled holes in timber elements. The mechanical advantages of BiRs include high local force capacity, improved strength, a relatively high stiffness and the possibility of ductile behaviour. They also offer aesthetic benefits, given that rods are hidden in the cross sections of wooden members. As such, BiR connections are regarded as a solution with great potential, but still uncertain design formulations. Several research projects have dealt with BiRs, but a final definition of their mechanics and a universal design procedure is still missing. This research study explores the typical fracture mechanics modes for BiR connections. A special focus is given to the evaluation of the impact of adhesive bonds under various operational conditions (i.e., moisture content of timber). A total of 84 specimens are tested in pull-out setup, and investigated with the support of digital image correlation (DIC). The reliability of empirical equations and a newly developed analytical model in support of design, based on linear elastic fracture mechanics (LEFM), is also assessed.

scholarly journals Effect of Different Bond Parameters on the Mechanical Properties of FRP and Concrete Interface

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2466
Author(s):  
Comfort Mensah ◽  
Zhenqing Wang ◽  
Alex Osei Bonsu ◽  
Wenyan Liang
Keyword(s):  
Ultimate Load ◽  
Image Correlation ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Bond Slip ◽  
Reinforced Polymer ◽  
Peak Shear Stress ◽  
Concrete Blocks ◽  
Length Width ◽  
Concrete Interface

This paper presents double shear tests performed to investigate factors influencing the bond behavior between basalt fiber-reinforced polymer (BFRP), glass fiber-reinforced polymer (GFRP) laminate, and concrete blocks. In detail, thirty-six twin concrete blocks strengthened with the aforementioned FRP types were tested to evaluate the influence of FRP length, width, and thickness, and their bonding behavior. The 2D-DIC (digital image correlation) technique and several strain gauges bonded along the laminate were used to measure the strain distributions of the FRP-to-concrete interface. The failure mode, ultimate load, load–slip, strain distribution, and bond–slip relationships between the laminates and concrete were analyzed. Furthermore, bond–slip curves were compared with some other existing literature models. The results from the experiment showed that the ultimate load, peak bond stress, and slip increased with the increase in the BFRP and GFRP laminates length, width, and thickness. The values of peak shear stress and the corresponding maximum shear slip were significantly different because of the above-mentioned factors’ influence on them. The bond interface that contributes to the bearing of the shear load may grow to an extent and later shift from the loaded end when debonding progresses. Finally, the fractured surfaces of the failed FRP laminates were examined using scanning electron microscope (SEM), revealing that FRP rupture, debonding in concrete, and debonding in an adhesive–concrete interface were the main failure types.

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