scholarly journals Failure Mechanisms of GFRP Scarf Joints under Tensile Load

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1806
Author(s):  
Carineh Ghafafian ◽  
Bartosz Popiela ◽  
Volker Trappe
Keyword(s):  
Failure Mechanism ◽  
Fiber Orientation ◽  
Structural Integrity ◽  
Tensile Load ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Scarf Joints ◽  
Restoration Failure ◽  
Recovery Assessment

A potential repair alternative to restoring the mechanical properties of lightweight fiber-reinforced polymer (FRP) structures is to locally patch these areas with scarf joints. The effects of such repair methods on the structural integrity, however, are still largely unknown. In this paper, the mechanical property restoration, failure mechanism, and influence of fiber orientation mismatch between parent and repair materials of 1:50 scarf joints are studied on monolithic glass fiber-reinforced polymer (GFRP) specimens under tensile load. Two different parent orientations of [−45/+45]2S and [0/90]2S are exemplarily examined, and control specimens are taken as a baseline for the tensile strength and stiffness property recovery assessment. Using a layer-wise stress analysis with finite element simulations conducted with ANSYS Composite PrepPost to support the experimental investigation, the fiber orientation with respect to load direction is shown to affect the critical regions and thereby failure mechanism of the scarf joint specimens.

scholarly journals 3D-Printed Pseudo Ductile Fiber-Reinforced Polymer (FRP) Composite Using Discrete Fiber Orientations

Fibers ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 53
Author(s):  
Shreya Vemuganti ◽  
Eslam Soliman ◽  
Mahmoud Reda Taha
Keyword(s):  
3D Printing ◽  
Fiber Orientation ◽  
Fiber Reinforced Polymer ◽  
Civil Infrastructure ◽  
Stacking Sequence ◽  
Fiber Reinforced ◽  
Frp Composite ◽  
Reinforced Polymer ◽  
Gfrp Composite ◽  
3D Printed

The use of fiber-reinforced polymer (FRP) composite materials are continuously growing in civil infrastructure due to their high strength, low weight, and manufacturing flexibility. However, FRP is characterized by sudden failure and lacks ductility. When used in construction, gradual failure of FRP components is desired to avoid catastrophic structural collapse. Due to its mechanical orthotropy, the behavior of FRP relies significantly on fiber orientation and stacking sequence. In this paper, a novel multi-angled glass fiber reinforced polymer (GFRP) composite laminate showing pseudo ductile behavior is produced using 3D-printing. This is accomplished by varying fiber orientation angles, stacking sequence, and thickness of lamina. Single-angled GFRP composite specimens were 3D-printed with different fiber orientation angles of 0°, 12°, 24°, 30°, 45°, and 90° using continuous and fused filament techniques. The tension test results of the single-angled specimens were then used to aid the design of multi-angled laminate for potential progressive failure behavior. A 3D finite element (FE) model was developed to predict the response of the experimental results and to provide insight into the failure mechanism of the multi-angled laminate. The experimental observations and the FE simulations show the possibility of producing pseudo ductile FRP-by-design composite using 3D-printing technology, which leads the way to fabricate next-generation composites for civil infrastructure.

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.

Prediction for the mechanical property of short fiber-reinforced polymer composites through process modeling method

2018 ◽  
Vol 32 (11) ◽  
pp. 1525-1546 ◽  
Author(s):  
Yue Mu ◽  
Anbiao Chen ◽  
Guoqun Zhao ◽  
Yujia Cui ◽  
Jiejie Feng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fiber Orientation ◽  
Orientation Distribution ◽  
Fiber Reinforced Composites ◽  
Fiber Reinforced Polymer ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Fiber Orientation Distribution

The fiber-reinforced polymer composites are important alternative for conventional structural materials because of their excellent comprehensive performance and weight reduction. The mechanical properties of such composite materials are mainly determined by the fiber orientation induced through practical manufacturing process. In the study, a through process modeling (TPM) method coupling the microstructure evolution and the mechanical properties of fiber-reinforced composites in practical processing is presented. The numerical methodology based on the finite volume method is performed to investigate three-dimensional forming process in the injection molding of fiber-reinforced composites. The evolution of fiber orientation distribution is successfully predicted by using a reduced strain closure model. The corresponding finite volume model for TPM is detailedly derived and the pressure implicit with splitting of operators (PISO) algorithm is employed to improve computational stability. The flow-induced multilayer structure is successfully predicted according to essential flow characteristics and the fiber orientation distribution. The mechanical properties of such anisotropy composites is further calculated based on the stiffness analysis and the Tandon–Weng model. The improvement of mechanical properties in each direction of the injection molded product are evaluated by using the established mathematical model and numerical algorithm. The influences of the geometric structure of injection mold cavity, the fiber volume fractions, and the fiber aspect ratios on the mechanical properties of composite products are further discussed. The mathematical model and numerical method proposed in the study can be successfully adopted to investigate the structural response of composites in practical manufacturing process that will be helpful for optimum processing design.

scholarly journals Vibration Characteristics of Carbon Fiber Reinforced Polymer Composites under Varying Fiber Orientation Composition

2019 ◽  
Vol 9 (2) ◽  
pp. 2905-2918
Keyword(s):  
Carbon Fiber ◽  
Natural Frequency ◽  
Mode Shape ◽  
Fiber Orientation ◽  
Composite Plates ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

Many engineering applications today are increasingly made of laminated composite plates. The properties of laminated composite plates can change as the laminate and fiber composition change, enabling the engineering structure and components to be customized according to the desired static or dynamic properties. Therefore, it is of interest to investigate variation in dynamic properties of composites under different fiber orientation composition to forecast their vibration response. In this study, the natural frequency and mode shape of carbon fiber-reinforced polymer composite plates were obtained numerically under varying composition of the 0°, ±45° and 90° fiber orientations. Sixteen different cases were simulated using finite element method, showing changes in the natural frequency and mode shape of carbon fiber-reinforced polymer composite plates with changes in the composition of the fiber orientation. The first five values of natural frequency and mode shape of the composite laminate were reported and analyzed using a surface regression method. In addition, the effect of the stacking sequence on the natural frequency of the composite plate having the same orientation composition was also analyzed. Comparison with previous studies showed good agreement of the present numerical modeling. Numerical results indicate potential to develop relationships to estimate modal properties based on composition of fiber orientation.

DYNAMIC ANALYSIS OF FIBER-REINFORCED POLYMER COMPOSITE ELECTRIC POLES

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Sara Mohamadi ◽  
Girum Urgessa
Keyword(s):  
Dynamic Analysis ◽  
Fundamental Frequency ◽  
Fiber Orientation ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Transient Dynamic Analysis ◽  
Transient Dynamic ◽  
Lamina Thickness ◽  
Reinforced Polymer ◽  
Number Of Layers

This paper presents finite element modeling of tapered fiber-reinforced polymer (FRP) poles in ABAQUS for dynamic analysis. Modal analysis and transient dynamic analysis are presented in order to evaluate the effect of fiber orientation, taper ratio, number of layers and lamina thickness on the dynamic properties of tapered poles. Trends observed from the parametric studies on the analyses of the FRP poles are enumerated. In addition, the effect of rectangular dynamic excitations on the overall response of the FRP poles is presented encapsulating impulsive loadings that may occur due to wind gusts or loss of cable tension supported by the FRP poles. Result shows that the fundamental frequency of the poles decreased as the fiber-orientation increased up to 60 degrees. In addition, the fundamental frequency of the poles increased as the number of layers increased. No significant difference was observed in natural frequency of the poles when varying the lamina thickness without changing the overall laminate thickness. The fundamental frequency of the FRP poles decreased by 10% as the taper ratio increased from 0.4 to 1. Transient dynamic analysis showed that FRP poles with higher fiber orientation angle had the larger maximum tip deflection. However, only small differences were observed when the deflections are normalized as the ratio of the maximum dynamic deformation to the maximum static deformation.

Simulation of a Composite Piezoelectric and Glass Fiber Reinforced Polymer Beam for Adaptive Stiffness Applications

2018 ◽  
Author(s):  
Srinivas Koushik Gundimeda ◽  
Selin Kunc ◽  
John A. Gallagher ◽  
Roselita Fragoudakis
Keyword(s):  
Glass Fiber ◽  
Fiber Orientation ◽  
Fiber Reinforced Polymer ◽  
Leaf Spring ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Spring Suspension ◽  
Piezoelectric Fiber

Glass Fiber Reinforced Polymer (GFRP) beams have shown over a 20% decrease in weight compared to more traditional materials without affecting system performance or fatigue life. These beams are being studied for use in automobile leaf-spring suspension systems to reduce the overall weight of the car therefore increasing fuel efficiency. These systems are subject to large amplitude mechanical vibrations at relatively constant frequencies, making them an ideal location for potential energy scavenging applications. This study analyses the effect on performance of GFRP beams by substituting various composite layers with piezoelectric fiber layers and the results on deflection and stiffness. Maximum deflection and stress in the beam is calculated for varying the piezoelectric fiber layer within the beam. Initial simulations of a simply supported multimorph beam were run in ABAQUS/CAE. The beam was designed with symmetric piezoelectric layers sandwiching a layer of S2-glass fiber reinforced polymer and modeled after traditional mono leaf-spring suspension designs with total dimensions 1480 × 72 × 37 mm3, with 27 mm camber. Both piezoelectric and GFRP layers had the same dimensions and initially were assumed to have non-directional bulk behavior. The loading of the beam was chosen to resemble loading of a leaf spring, corresponding to the stresses required to cycle the leaf at a stress ratio between R = 0.2 and 0.4, common values in heavy-duty suspension fatigue analysis. The maximum stresses accounted for are based on the monotonic load required to set the bottom leaf surface under tension. These results were then used in a fiber orientation optimization algorithm in Matlab. Analysis was conducted on a general stacking sequence [0°/45°]s, and stress distributions for cross ply [0°/90°]s, and angle ply [+45°/−45°]s were examined. Fiber orientation was optimized for both the glass fiber reinforced polymer layer to maximize stiffness, and the piezoelectric fiber layers to simultaneously minimize the effect on stiffness while minimizing deflection. Likewise, these fibers could be activated through the application of electric field to increase or decrease the stiffness of the beam. The optimal fiber orientation was then imported back into the ABAQUS/CAE model for a refined simulation taking into account the effects of fiber orientation on each layer.

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