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 Compressive Strength of Modified FRP Hybrid Bars

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1898
Author(s):  
Marek Urbański
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Basalt Fiber ◽  
Test Method ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Free Length ◽  
Compression Properties ◽  
Reinforced Polymer ◽  
Frp Bars

A new type of HFRP hybrid bars (hybrid fiber reinforced polymer) was introduced to increase the rigidity of FRP reinforcement, which was a basic drawback of the FRP bars used so far. Compared to the BFRP (basalt fiber reinforced polymer) bars, modification has been introduced in HFRP bars consisting of swapping basalt fibers with carbon fibers. One of the most important mechanical properties of FRP bars is compressive strength, which determines the scope of reinforcement in compressed reinforced concrete elements (e.g., column). The compression properties of FRP bars are currently ignored in the standards (ACI, CSA). The article presents compression properties for HFRP bars based on the developed compression test method. Thirty HFRP bars were tested for comparison with previously tested BFRP bars. All bars had a nominal diameter of 8 mm and their nonanchored (free) length varied from 50 to 220 mm. Test results showed that the ultimate compressive strength of nonbuckled HFRP bars as a result of axial compression is about 46% of the ultimate strength. In addition, the modulus of elasticity under compression does not change significantly compared to the modulus of elasticity under tension. A linear correlation of buckling load strength was proposed depending on the free length of HFRP bars.

scholarly journals Time-Dependent Behavior of Reinforced Polymer Concrete Columns under Eccentric Axial Loading

Materials ◽  
2012 ◽  
Vol 5 (11) ◽  
pp. 2342-2352 ◽  
Author(s):  
Valentino Berardi ◽  
Geminiano Mancusi
Keyword(s):  
Axial Loading ◽  
Concrete Columns ◽  
Time Dependent ◽  
Polymer Concrete ◽  
Reinforced Polymer ◽  
Dependent Behavior

Time-Dependent Deterioration of Carbon Fiber Reinforced Polymer Affected by Climatic Factors

2012 ◽  
Vol 457-458 ◽  
pp. 320-324
Author(s):  
Luo Yi ◽  
Xin Qian Peng ◽  
Quan Feng Wang ◽  
Yong Xin Yang
Keyword(s):  
Carbon Fiber ◽  
Climatic Factors ◽  
Fiber Reinforced Polymer ◽  
Time Dependent ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

Experimental study on the behavior of carbon fiber reinforced polymer sheets bonded to concrete

2006 ◽  
Vol 33 (11) ◽  
pp. 1438-1449 ◽  
Author(s):  
Ayman S Kamel ◽  
Alaa E Elwi ◽  
Roger J.J Cheng
Keyword(s):  
Carbon Fiber ◽  
Failure Mechanism ◽  
Test Method ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Bond Behavior ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

This paper presents a study on the interfacial behavior of carbon fiber reinforced polymer (CFRP) sheets when applied to concrete members as external reinforcement. Two bond test methods that are detailed in the paper were used in separate test series to study the bond behavior and failure mechanism of CFRP sheets bonded to concrete. A modified push-apart test method was proposed and tested. It was concluded that there existed an effective length beyond which there will be no increase in the ultimate capacity of the joint. An experimental test method to determine the effective bond length was also proposed and tested. The strains at the edge of the CFRP sheets are consistently higher than those at the center. The anchorage requirements for the CFRP sheets were also investigated in this study. Anchor sheets placed at 90° to the primary test sheets and bonded underneath the tested sheet showed better or equivalent overall bond behavior compared with those bonded on top of the tested sheet. The distance at which the anchor sheet is placed from the crack does not appear to change the bond behavior.Key words: bond, concrete, debonding, failure mechanism, carbon fiber reinforced polymer (CFRP) sheets, anchor sheets.

Development of a Novel Technique Using Finite Element Method to Simulate Creep in Thermoplastic Fiber Reinforced Polymer Composite Pipe Structures

2020 ◽  
Author(s):  
Hossein Ashrafizadeh ◽  
Ryan Schultz ◽  
Bo Xu ◽  
Pierre Mertiny
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Creep Rate ◽  
High Stress ◽  
Three Dimensional ◽  
Fiber Reinforced Polymer ◽  
Time Dependent ◽  
Fiber Reinforced ◽  
Anisotropic Properties ◽  
Reinforced Polymer

Abstract High strength-to-weight ratio, excellent corrosion resistance, flexibility, superior fatigue performance, and cost competitiveness have made thermoplastic fiber reinforced polymer composites (TP-FRPCs) a material of choice for the manufacture of pipe products for use in the oil and gas industry. The TP matrix not only protects the composite structure from brittle cracking caused by dynamic loads, it also provides improved flexibility for bending of pipes to enable easier field installation and reduces the requirement for pre-fabricated bent connections. Despite the attractive mechanical performance, the design, development and qualification evaluation of TP-FRPC components for a large portion relies on experimental testing. The time and expense of manufacturing new composite prototypes and performing full-scale testing emphasizes the value of a predictive modeling. But, modeling TP-FRPC structures is not a trivial task due to their anisotropic and time-dependent properties. In this study, a new technique based on the finite element method is proposed to model anisotropic time-dependent behavior of TP-FRPCs. In the proposed technique the composite mechanical properties are captured by superimposing the properties of two fictitious materials. To that end, two overlapping three-dimensional elements with similar nodes were assigned different material properties. One of the elements is assigned to have time-dependent properties to capture the viscoelastic behavior of the matrix while the other element is given linear anisotropic properties to account for the anisotropy induced by the fiber reinforcement. The model was calibrated using data from uniaxial tensile creep tests on coupons made from pure matrix resin and uniaxial tension tests on TP-FRPC tape parallel to the fiber direction. Combined time hardening creep formulation, ANSYS 19.2 implicit analysis, and ANSYS Composite PrepPost were employed to formulate the three-dimensional finite element model. The model was validated by comparison of model predictions with experimental creep strain obtained from TP FRPC tubes with ±45° fiber layups subjected to uniaxial intermediate and high stress for 8 hours. The results obtained showed that for the tubes subjected to intermediate stress, the model predicted the creep rate in the secondary region with less than 5% error. However, for tubes subjected to high stress, the model overestimated the creep rate with over 30% error. This behavior was due to large deformation at this high level of stress and inability of the model to capture fiber realignment towards the pipe longitudinal direction and, therefore, capture an increase in stiffness. Overall, comparison of the simulation results with experimental data indicated that the technique proposed can be used as a reliable model to account for deformations caused by secondary creep in the design of TP-FRPC structures as far as deformations are relatively small and limited to a certain strain threshold. Acceptable predictions of the model, its simplicity in calibration, and limitations on available models that can simultaneously account for time-dependency and anisotropic properties, further emphasize the value of the developed model.

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