Numerical and experimental investigation of the interface properties and failure strength of CFRP T-Stiffeners subjected to pull-off load

Ma, Xueshi; Kan, Biao; Liu, Hongguang; Wang, Yi; Xiong, Ke

doi:10.1016/j.matdes.2019.108231

Cited by 15 publications

(3 citation statements)

References 21 publications

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“…Therefore, bonded composite structural components are widely used in aircraft [ 9 ]. Research on composite bonding mainly involves the design and performances of adhesives [ 10 , 11 , 12 ], the mechanical behavior and properties of adhesive-bonded composite joints [ 13 , 14 , 15 ], analysis methods [ 4 , 16 ], and numerical simulations [ 17 , 18 , 19 ]. The methods for bonding composite materials mainly include co-curing, co-bonding, and secondary bonding.…”

Section: Introductionmentioning

confidence: 99%

Epoxy-Modified Bismaleimide Structural Adhesive Film Toughened Synergistically with PEK-C and Core–Shell Polymers for Bonding CFRP

Zhao

Xiao

et al. 2023

Polymers

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Bismaleimide (BMI) resin-based structural adhesives have excellent heat resistance, with important applications demonstrated in the bonding of high-temperature BMI composites. In this paper, we report an epoxy-modified BMI structural adhesive with excellent properties for bonding BMI-based CFRP. We prepared the BMI adhesive using epoxy-modified BMI as the matrix and PEK-C and core–shell polymers as synergistic tougheners. We found that the epoxy resins improve the process and bonding properties of BMI resin but slightly reduce thermal stability. PEK-C and core–shell polymers synergistically improve the toughness and bonding performances of the modified BMI adhesive system and allow the maintenance of heat resistance. The optimized BMI adhesive exhibits excellent heat resistance, with a high glass transition temperature of 208.6 °C and a high thermal degradation temperature of 425.4 °C. Most importantly, the optimized BMI adhesive exhibits satisfactory intrinsic bonding and thermal stability. It has a high shear strength of 32.0 MPa at room temperature and up to 17.9 MPa at 200 °C. The BMI adhesive-bonded composite joint has a high shear strength of 38.6 and 17.3 MPa at room temperature and 200 °C, respectively, indicating effective bonding and excellent heat resistance.

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Section: Introductionmentioning

confidence: 99%

Epoxy-Modified Bismaleimide Structural Adhesive Film Toughened Synergistically with PEK-C and Core–Shell Polymers for Bonding CFRP

Zhao

Xiao

et al. 2023

Polymers

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“…Carbon fiber reinforced plastic (CFRP), in which the lightweight, high strength, and preferable toughness are provided [ 1 , 2 ], has been broadly used in aircraft and hydrogen fuel cell vehicles (e.g., airfoils and composite pressure vessels). However, delamination within CFRP structures arising from complicated manufacturing processes and extreme loading conditions may occur before and after service, leading to a reduction in the mechanical properties of the materials and a threat to the structural integrity [ 3 ]. Therefore, the effective non-destructive evaluation (NDE) of delamination is necessary for the avoidance of catastrophic accidents for those critical engineering structures [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic Phased Array Imaging Approach Using Omni-Directional Velocity Correction for Quantitative Evaluation of Delamination in Composite Structure

Fan

Chen

et al. 2023

Sensors

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The ultrasonic detectability of buried defects within composite materials is dependent on the anisotropy of the composite material by which the propagation property of acoustic wave in each direction is variably affected. In this study, the characteristics of acoustic waves propagating in different directions for composite materials are explored based on the full matrix capture (FMC) data using an ultrasonic phased array. The elastic constant of multidirectional carbon fiber reinforced plastic (CFRP) laminate is first derived based on the genetic algorithm. The characteristics of transmitted and reflected waves in higher angles are predicted by implementing the Christoffel equation, and the focal law used in post-processing of FMC data can be optimized accordingly. The imaging results of the total focusing method (TFM) using the improved focal law are compared with the results of the conventional TFM. The results suggest that the optimized TFM can effectively characterize the defect by reducing the background noise. Furthermore, since it is impractical to theoretically correct angle-dependent velocity for in situ inspection, a linear extrapolation method based on the experimentally measurable velocity at low angles is proposed to estimate the velocity profile at higher angles. The imaging results using the fast extrapolated velocity profile is then compared with the theoretical, and it has been demonstrated that while the difference between the images using the theoretical focal law and the linearly extrapolated one is barely visible, the later one is overwhelmingly advantageous to be realiszd for engineering practices.

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“…In T-joints, the stiffener can be a single part or composed of two L-shaped elements joined by co-curing or a structural adhesive. Using the last configuration (two L-shaped elements), Ma et al [24] numerically (using the extended finite element method combined with cohesive zone model) and experimentally studied the damage mechanisms of carbon fiber reinforced polymer (CFRP) T-stiffeners subjected to pull-off loads. Contrary to what is reported in the literature, in which the final failure begins with the debonding in the radius region and then spreads to the stringer-skin interface, these authors observed a crack that begins in the filler region and near the fillet apex due to the stress concentration in this region.…”

Section: Introductionmentioning

confidence: 99%

Static and Fatigue Characterization of Adhesive T-Joints Involving Different Adherends

Serra,

Ferreira,

Reis

2023

Processes

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It is very important to understand the damage mechanisms as well as the mechanical response of T-joints involving different materials on the base plate. For this purpose, two configurations were studied. In one, the joint is composed of a base plate and a T-element, both in Al 6063-T5, while in the other one, the aluminum base plate was replaced by a glass fiber composite. Finally, each configuration was divided into two batches, where in one, the elements were bonded with a stiff adhesive (Araldite® AV 4076-1/HY 4076) while in the other, a more ductile adhesive (Araldite® AW 106/HV 953 U) was used. The static and fatigue strength of all configurations was evaluated in bending. In all cases, the damage occurred at the end of the T-element, where a crack appeared and propagated toward the interior of the T-joint. The bending strength is highest for joints involving aluminum and the ductile adhesive, which is 2.8 times higher than the same configuration involving composite base plates and 1.7 times higher than that using the stiff adhesive. Finally, the highest fatigue lives were obtained for T-joints involving Al 6063-T5 base plates, and regardless of the base plate material, the ductile adhesive promoted the highest fatigue strength.

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Numerical and experimental investigation of the interface properties and failure strength of CFRP T-Stiffeners subjected to pull-off load

Cited by 15 publications

References 21 publications

Epoxy-Modified Bismaleimide Structural Adhesive Film Toughened Synergistically with PEK-C and Core–Shell Polymers for Bonding CFRP

Epoxy-Modified Bismaleimide Structural Adhesive Film Toughened Synergistically with PEK-C and Core–Shell Polymers for Bonding CFRP

Ultrasonic Phased Array Imaging Approach Using Omni-Directional Velocity Correction for Quantitative Evaluation of Delamination in Composite Structure

Static and Fatigue Characterization of Adhesive T-Joints Involving Different Adherends

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