Materials

Research

19 pages, 2228 KiB

Open AccessEditor’s ChoiceArticle

The Design of a Piecewise-Integrated Composite Bumper Beam with Machine-Learning Algorithms

by Seokwoo Ham, Seungmin Ji and Seong Sik Cheon

Materials 2024, 17(3), 602; https://doi.org/10.3390/ma17030602 - 26 Jan 2024

Cited by 1 | Viewed by 1128

In the present study, a piecewise-integrated composite bumper beam for passenger cars is proposed, and the design innovation process for a composite bumper beam regarding a bumper test protocol suggested by the Insurance Institute for Highway Safety is carried out with the help [...] Read more.

In the present study, a piecewise-integrated composite bumper beam for passenger cars is proposed, and the design innovation process for a composite bumper beam regarding a bumper test protocol suggested by the Insurance Institute for Highway Safety is carried out with the help of machine learning models. Several elements in the bumper FE model have been assigned to be references in order to collect training data, which allow the machine learning model to study the method of predicting loading types for each finite element. Two-dimensional and three-dimensional implementations are provided by machine learning models, which determine the stacking sequences of each finite element in the piecewise-integrated composite bumper beam. It was found that the piecewise-integrated composite bumper beam, which is designed by a machine learning model, is more effective for reducing the possibility of structural failure as well as increasing bending strength compared to the conventional composite bumper beam. Moreover, the three-dimensional implementation produces better results compared with results from the two-dimensional implementation since it is preferable to choose loading-type information, which is achieved from surroundings when the target elements are located either at corners or junctions of planes, instead of using information that comes from the identical plane of target elements. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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14 pages, 10632 KiB

Open AccessEditor’s ChoiceArticle

On Impact Damage and Repair of Composite Honeycomb Sandwich Structures

by Hang Zhang, Xiaopei Wang, Zhenhan Guo, Yuan Qian, Yan Shang and Deng’an Cai

Materials 2023, 16(23), 7374; https://doi.org/10.3390/ma16237374 - 27 Nov 2023

Viewed by 1860

Abstract

This study is conducted on glass fiber-reinforced composite honeycomb sandwich structures by introducing delamination damage through low-velocity impact tests, establishing a three-dimensional progressive damage analysis model, and evaluating the delamination damage characteristics and laws of honeycomb sandwich structures under different impact energies through [...] Read more.

This study is conducted on glass fiber-reinforced composite honeycomb sandwich structures by introducing delamination damage through low-velocity impact tests, establishing a three-dimensional progressive damage analysis model, and evaluating the delamination damage characteristics and laws of honeycomb sandwich structures under different impact energies through experiments. Repair techniques and process parameters for delamination damage are explored. It is found that as the impact energy increases, the damage area of honeycomb sandwich panels also increases, and the delamination damage extends from the impact center to the surrounding areas, accompanied by damage such as fiber fracture and matrix cracking. The strength recovery rates of sandwich panels at impact energies of 5 J, 15 J, and 25 J after repair are 71.90%, 65.89%, and 67.10%, respectively, which has a considerable repair effect. In addition, a progressive damage model for low-velocity impact on the composite honeycomb sandwich structure is established, and its accuracy and reliability are verified. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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15 pages, 3717 KiB

Open AccessArticle

Shear Strength Behaviors of Aeolian Sand Solidified by Microbially Induced Calcite Precipitation and Basalt Fiber Reinforcement

by Gang Li, Jia Liu, Jinli Zhang, Yiran Yang and Shufeng Chen

Materials 2023, 16(17), 5857; https://doi.org/10.3390/ma16175857 - 26 Aug 2023

Cited by 2 | Viewed by 1259

Abstract

Aeolian sand flow is identified as the main factor in the formation of sandstorms. However, conventional sand fixation methods cannot meet the current development requirements of environmental protection. In this paper, the method using Microbially Induced Calcite Precipitation (MICP) combined with basalt fiber [...] Read more.

Aeolian sand flow is identified as the main factor in the formation of sandstorms. However, conventional sand fixation methods cannot meet the current development requirements of environmental protection. In this paper, the method using Microbially Induced Calcite Precipitation (MICP) combined with basalt fiber reinforcement (BFR) was adopted to solidify the aeolian sand. Consolidated undrained triaxial shear tests were carried out to analyze the influence of fiber content, fiber length, confining pressure, and other factors on stress–strain characteristics, peak strength, brittleness index, and shear strength of aeolian sand. A shear strength model of aeolian sand solidification using MICP-BFR and considering the effect of fiber length and fiber content is established according to the test results. The results show that the peak strength of aeolian sand solidified by MICP-BFR is remarkably higher than that of aeolian sand solidified by MICP alone, and the peak strength rises with the increasing fiber length, fiber content, and confining pressure. The application of fiber can effectively reduce the brittleness index of aeolian sand solidified by MICP and improve the sample ductility. As fiber content and fiber length increase, the cohesion of solidified aeolian sand increases while the internal friction angle changes relatively little. In the limited range set by the test, the fiber length of 12 mm and the fiber content of 1.0% constitute the optimum reinforcement condition. The test results coincide with the model prediction results, indicating that the new model is fitting for predicting the shear strength of aeolian sand solidified by MICP-BFR. The research results provide an important reference value for guiding the practice of wind prevention and sand fixation in desert areas. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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13 pages, 8736 KiB

Open AccessArticle

Experimental Study on the Mechanical Behaviors of Aeolian Sand Treated by Microbially Induced Calcite Precipitation (MICP) and Basalt Fiber Reinforcement (BFR)

by Jia Liu, Xi’an Li, Gang Li and Jinli Zhang

Materials 2023, 16(5), 1949; https://doi.org/10.3390/ma16051949 - 27 Feb 2023

Cited by 6 | Viewed by 1742

Abstract

Aeolian sand flow is a major cause of land desertification, and it is prone to developing into a dust storm coupled with strong wind and thermal instability. The microbially induced calcite precipitation (MICP) technique can significantly improve the strength and integrity of sandy [...] Read more.

Aeolian sand flow is a major cause of land desertification, and it is prone to developing into a dust storm coupled with strong wind and thermal instability. The microbially induced calcite precipitation (MICP) technique can significantly improve the strength and integrity of sandy soils, whereas it easily leads to brittle destruction. To effectively inhibit land desertification, a method coupled with MICP and basalt fiberreinforcement (BFR) was put forward to enhance the strength and toughness of aeolian sand. Based on a permeability test and an unconfined compressive strength (UCS) test, the effects of initial dry density (ρ_d), fiber length (FL), and fiber content (FC) on the characteristics of permeability, strength, and CaCO₃ production were analyzed, and the consolidation mechanism of the MICP-BFR method was explored. The experiments indicated that the permeability coefficient of aeolian sand increased first, then decreased, and subsequently increased with the increase in FC, whereas it exhibited a tendency to decrease first and then increase with the increase in FL. The UCS increased with the increase in the initial dry density, while it increased first and then decreased with the increase in FL and FC. Furthermore, the UCS increased linearly with the increase in CaCO₃ generation, and the maximum correlation coefficient reached 0.852. The CaCO₃ crystals played the roles of providing bonding, filling, and anchoring effects, and the spatial mesh structure formed by the fibers acted as a bridge effect to enhance the strength and brittle damage of aeolian sand. The findings could supply a guideline for sand solidification in desert areas. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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18 pages, 4134 KiB

Open AccessArticle

Study on Epoxy Resin Composite Reinforced with Rice Straw Fiber

by Xinzhen Liu, Jiaxin Wang, Tianqi Liu, Qian Cheng, Anhui Li, Yuge Li, Zihui Liu, Jiayi Sun and Dejun Liu

Materials 2023, 16(4), 1370; https://doi.org/10.3390/ma16041370 - 6 Feb 2023

Cited by 3 | Viewed by 3192

Abstract

In order to enhance the performance of the epoxy resin-prepared materials, straw fiber was used as the reinforcing base in this study. The principle of this study is to use the cellulose component exposed after the defibrillation of straw fiber can be further [...] Read more.

In order to enhance the performance of the epoxy resin-prepared materials, straw fiber was used as the reinforcing base in this study. The principle of this study is to use the cellulose component exposed after the defibrillation of straw fiber can be further combined with the epoxy group. Firstly, the degree of defibrillation of straw fiber under three different pretreatment methods of acid, alkali and moist heat treatment was explored, and a control test was conducted with untreated straw fiber, which showed that the defibrillation of the straw fiber after alkali treatment was better than the other two methods. Secondly, to prove the comprehensive effect of the pretreatment method and straw fiber filling amount on the composite material performance, this paper carried out a tensile, bending, density and water absorption test. The results showed that when the straw fiber filling was 15%, the best performance of the composites was achieved by the alkali treatment, with tensile strength and tensile modulus reaching 1.89 KN and 3.92 MPa, bending strength and bending modulus reaching 2.00 KN and 81.65 MPa, average water absorption reaching 2.77%, and density reaching 0.957 g/cm³. Finally, the results were verified using Image J software was used for verification. After comparison, the material meets the basic requirements of high-density fiberboard material and provides a reference for preparing straw epoxy resin composites. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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24 pages, 9811 KiB

Open AccessArticle

Carbonation Resistance and Pore Structure of Mixed-Fiber-Reinforced Concrete Containing Fine Aggregates of Iron Ore Tailings

by Wenbo Zheng, Sheliang Wang, Xiaoyi Quan, Yang Qu, Zhikai Mo and Changjun Lin

Materials 2022, 15(24), 8992; https://doi.org/10.3390/ma15248992 - 16 Dec 2022

Cited by 6 | Viewed by 1725

Abstract

The disposal of industrial by-product tailings has become an important issue in solving environmental pollution. In this study, 15%, 30%, 50%, and 70% iron tailings were used to replace the natural sand in concrete, and 1.5% steel fiber and 0–0.75% PVA fibers were [...] Read more.

The disposal of industrial by-product tailings has become an important issue in solving environmental pollution. In this study, 15%, 30%, 50%, and 70% iron tailings were used to replace the natural sand in concrete, and 1.5% steel fiber and 0–0.75% PVA fibers were added to the iron tailings concrete. The effects of the iron tailings replacement rate and the fiber content on the mechanical properties, carbonization depth, and concrete porosity were studied in a carbonization environment. The results demonstrated that the compressive and splitting tensile strengths of concrete first increased and subsequently decreased with an increase in the iron tailings replacement rate, while the carbonation depth and porosity initially decreased and subsequently increased. When the replacement rate of iron tailings was 30%, the compressive strength and split tensile strength were increased by 7.6% and 17.7%, respectively, and the porosity was reduced by 8.9%. The compressive strength, carbonation depth and porosity of single-doped steel-fiber concrete were superior to those of ordinary iron tailings concrete. However, compared with single-doped steel fiber, the performance of steel-PVA fiber was further improved. Based on the mechanical properties, the carbonation depth test results of the three aforementioned types of concrete, the mathematical expression of the uniaxial compression stress–strain curve of iron tailings concrete, and the prediction equation of the carbonation depth of mixed-fiber iron tailings concrete were proposed. This study provides a reference for the application and popularization of fiber-reinforced iron tailings concrete in carbonization environments. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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16 pages, 7194 KiB

Open AccessArticle

Research on Bending and Ballistic Performance of Three-Dimensional Ply-to-Ply Angle Interlock Kevlar/EP Armor Material

by Mengxiao Wang, Lin Zhong, Haijian Cao, Hongxia Chen and Xiaomei Huang

Materials 2022, 15(19), 6994; https://doi.org/10.3390/ma15196994 - 9 Oct 2022

Cited by 2 | Viewed by 1892

Abstract

The three-dimensional (3D) shallow cross-bending composite material has many advantages in thickness and in-plane direction, such as high strength, high modulus, inter-layer shear strength, as well as large-area area bearing, energy absorption, etc., which has great application potential in the field of bulletproof [...] Read more.

The three-dimensional (3D) shallow cross-bending composite material has many advantages in thickness and in-plane direction, such as high strength, high modulus, inter-layer shear strength, as well as large-area area bearing, energy absorption, etc., which has great application potential in the field of bulletproof armor. To prepare a protective material with both excellent bending performance and good ballistic performance, the effects of weft density and layering method on the bending performance and ballistic performance of three-dimensional ply-to-ply angle interlock (3DPPAI) Kevlar/EP armor materials were studied. The results showed that when the weft density of the material was 33 pieces/cm, its bending performance and ballistic resistance were the best. The 3DPPAI Kevlar/EP armor material prepared by orthogonal layup had more advantages in bending performance, and the unidirectional layup had better anti-ballistic performance. The research results will lay the foundation for structural optimization and engineering applications of such materials. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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18 pages, 7609 KiB

Open AccessArticle

Research on Bending Performance of Three-Dimensional Deep Angle Interlock Kevlar/EP Armor Material

by Jianhua Zheng, Lin Zhong, Hongxia Chen, Xiaomei Huang and Haijian Cao

Materials 2022, 15(15), 5321; https://doi.org/10.3390/ma15155321 - 2 Aug 2022

Cited by 3 | Viewed by 1597

Abstract

Three-dimensional (3D) woven composites have attracted much attention in the lightweight research of protective armor due to their high specific strength and good impact resistance. However, there are still many gaps in terms of the performance and influencing factors of three-dimensional deep-angle-interlock (3DDAI) [...] Read more.

Three-dimensional (3D) woven composites have attracted much attention in the lightweight research of protective armor due to their high specific strength and good impact resistance. However, there are still many gaps in terms of the performance and influencing factors of three-dimensional deep-angle-interlock (3DDAI) Kevlar/EP armor materials. Therefore, in order to prepare 3DDAI Kevlar/EP armor materials with excellent ballistic resistance and mechanical properties, this paper studies the bending performance of 3DDAI Kevlar/EP armor materials and the influence of the number of stacking layers, resin content, laying method, and weft density. Finally, we compare it with the traditional two-dimensional (2D) plain laminated Kevlar/EP armor material. The results showed that when the 3DDAI Kevlar/EP armor material was subjected to bending load, the upper and bottom layers of the material had a great influence on the initial stiffness and fracture strength of the material, respectively; when the material’s warp and weft density are quite different, the utilization rate of the yarn and the strength of the material are negatively affected; the fracture energy of the 3DDAI Kevlar/EP armor material prepared by the orthogonal laying method was about 20% higher than that of the 3DDAI Kevlar/EP armor material with the unidirectional layering method; and the bending performance of the 3DDAI Kevlar/EP armor material in the weft direction was better than that of the 2D plain laminated Kevlar/EP armor material, with the 3DDAI Kevlar/EP armor material having better delamination resistance. The research results will lay the foundation for structural optimization and engineering applications of such materials. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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16 pages, 5864 KiB

Open AccessArticle

A Three-Dimensional Equivalent Stiffness Model of Composite Laminates with Wrinkle Defects

by Haozhong Hu, Zhiyuan Mei and Huadong Li

Materials 2022, 15(15), 5264; https://doi.org/10.3390/ma15155264 - 29 Jul 2022

Cited by 3 | Viewed by 1680

Abstract

The stiffness of composite laminates is easily affected by wrinkle defects. In this paper, a new effective analytical model was proposed to predict the three-dimensional equivalent elastic properties of multidirectional composite laminates with wrinkle defects. Firstly, a geometric model was established according to [...] Read more.

The stiffness of composite laminates is easily affected by wrinkle defects. In this paper, a new effective analytical model was proposed to predict the three-dimensional equivalent elastic properties of multidirectional composite laminates with wrinkle defects. Firstly, a geometric model was established according to the microscopic characteristics of wrinkle defects. Then, based on the classical laminate theory and homogenization method, the constitutive equation and flexibility matrix of the wrinkle region were established. Finally, the equivalent stiffness parameters of unidirectional and multidirectional laminates were derived, and the effects of different wrinkle parameters and ply-stacking sequences on the stiffness of unidirectional and multidirectional laminates were studied by using the analytical model. The results show that the mechanical properties of the lamina and laminates are affected by the out-of-plane angle and in-plane angle of the wrinkle defects. The accuracy of the analytical model has been verified by the numerical model and other theoretical models, and it has the characteristics of few parameters and a high efficiency. The analytical model can be used to predict the stiffness of composite structures with wrinkle defects simply, effectively, and quantitatively. It can also be used as a tool to provide the mechanical response information of laminates with wrinkle defects. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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10 pages, 3856 KiB

Open AccessArticle

The Influence of SiO₂ + SiC + Al (H₂PO₄)₃ Coating on Mechanical and Dielectric Properties for SiC_f/MWCNTS/AlPO₄ Composites

by Yan Zhu, Feng Wan, Jianhui Yan and Hongmei Xu

Materials 2022, 15(15), 5178; https://doi.org/10.3390/ma15155178 - 26 Jul 2022

Viewed by 1544

Abstract

SiC fiber-reinforced AlPO₄ matrix (SiC_f/MWCNTs/AlPO₄) composites were fabricated using a hot laminating process with multi-walled carbon nanotubes (MWCNTs) as the absorber. A coating prepared from SiO₂ + SiC + Al (H₂PO₄)₃ was [...] Read more.

SiC fiber-reinforced AlPO₄ matrix (SiC_f/MWCNTs/AlPO₄) composites were fabricated using a hot laminating process with multi-walled carbon nanotubes (MWCNTs) as the absorber. A coating prepared from SiO₂ + SiC + Al (H₂PO₄)₃ was applied to the surface of the SiC_f/MWCNTs/AlPO₄ composites prior to an anti-oxidation test at 1273 K in air for 40 h. The anti-oxidation effect was verified by a three-point bending test, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and a dielectric property test. Anti-oxidation mechanism investigations revealed that the coating effectiveness could be attributed to three substances, i.e., SiO₂, SiP₂O_7, and SiO₂ + AlPO₄ solid solution from the reactions of SiC + O₂→SiO₂ + CO, SiO₂ + P₂O₅→SiP₂O₇ and SiO₂ + AlPO₄→solid solution, respectively. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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24 pages, 8827 KiB

Open AccessArticle

A Comparative Study to Evaluate the Essential Work of Fracture to Measure the Fracture Toughness of Quasi-Brittle Material

by Mohammed Y. Abdellah, Abdul-Rahman Zuwawi, Sufyan A. Azam and Mohamed K. Hassan

Materials 2022, 15(13), 4514; https://doi.org/10.3390/ma15134514 - 27 Jun 2022

Cited by 8 | Viewed by 2241

Abstract

In the present work, three different woven composite laminates were fabricated using the hand lay-up method. The woven reinforcement fibres were carbon fibres (CFRP), glass fibres (GFRP-W) and (GFRP-R) in combination with epoxy resin. Then, the central notch specimen tensile test (CNT) was [...] Read more.

In the present work, three different woven composite laminates were fabricated using the hand lay-up method. The woven reinforcement fibres were carbon fibres (CFRP), glass fibres (GFRP-W) and (GFRP-R) in combination with epoxy resin. Then, the central notch specimen tensile test (CNT) was used to measure the fracture toughness and the corresponding surface release energy (

G_{I C}

). Then, the data were compared with the essential work of fracture (we) values based on the stored energy of the body to obtain a new standard fracture toughness test for composite laminates using relatively simple techniques. In addition to an extended finite element model, XFEM was implemented over a central notch specimen geometry to obtain a satisfactory validation of the essential work of fracture concepts. Therefore, the average values of (

G_{I C}

) were measured with CNT specimens 25.15 kJ/m², 32.5 kJ/m² and 20.22 kJ/m² for CFRP, GFRP-W and GFRP-R, respectively. The data are very close as the percentage error for the surface release energy measured by the two methods was 0.83, 4.6 and 5.16 for carbon, glass and random fibre composite laminates, respectively. The data for the fracture toughness of XFEM are also very close. The percentage error is 4.6, 5.25 and 2.95 for carbon, glass and random fibre composite laminates, respectively. Therefore, the fundamental work of the fracture concept is highly recommended as a fracture toughness test for composite laminates or quasi-brittle Material. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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20 pages, 12743 KiB

Open AccessArticle

Non-Destruction Evaluation Method for Long-Term Oxidation Behavior of SiC/SiC Composites with Different Preforms in Wet Oxygen

by Guodong Sun, Yan Wu, Xin’gang Luan, Xinming Xu, Xinxin Cao, Jiahao Zhang, Huan Zhao, Qing Zhang and Laifei Cheng

Materials 2022, 15(11), 3812; https://doi.org/10.3390/ma15113812 - 27 May 2022

Cited by 2 | Viewed by 1594

Abstract

The implementation of SiC fiber reinforced SiC/SiC composites to aero-engine hot components has attracted wide attention, due to their many excellent properties. Along these lines, in order to predict the oxidation behavior of the material in extreme environments and to explore the effect [...] Read more.

The implementation of SiC fiber reinforced SiC/SiC composites to aero-engine hot components has attracted wide attention, due to their many excellent properties. Along these lines, in order to predict the oxidation behavior of the material in extreme environments and to explore the effect of different preforms on the oxidative behavior of the composites, four SiC/SiC composites, with different preforms, were oxidized under environmental conditions of pressure of 12 kPa H₂O:8 kPa O₂:80 kPa Ar, at 1400 °C temperature. Moreover, the morphology and defect distribution of the samples were characterized by carrying out scanning electron microscopy, and micro-computed X-ray tomography measurements. Furthermore, the relation between the micro- and macro-scales was established, so as to be able to predict the oxidation behavior of the composites; not only the quantitative relationship between the mass change rate and the defect volume change rate, but also the combination of micro-computed X-ray images. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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14 pages, 3808 KiB

Open AccessArticle

Accelerated Aging of Epoxy Biocomposites Filled with Cellulose

by Radosław Busiak, Anna Masek, Aleksandra Węgier and Adam Rylski

Materials 2022, 15(9), 3256; https://doi.org/10.3390/ma15093256 - 1 May 2022

Cited by 4 | Viewed by 1976

Abstract

The presented research concerns the mechanochemical modification of a snap-cure type of epoxy resin, A.S. SET 1010, with the addition of different amounts of cellulose (0, 2, 5, 10, 15 and 20 per 100 resin), for a novel, controlled-degradation material with possible application [...] Read more.

The presented research concerns the mechanochemical modification of a snap-cure type of epoxy resin, A.S. SET 1010, with the addition of different amounts of cellulose (0, 2, 5, 10, 15 and 20 per 100 resin), for a novel, controlled-degradation material with possible application in the production of passenger seats in rail transport. Composite samples were prepared on a hydraulic press in ac-cordance with the resin manufacturer’s recommendations, in the form of tiles with dimensions of 80 × 80 × 1 mm. The prepared samples were subjected to thermo-oxidative aging and weathering for a period of 336 h. Changes in the color and surface defects in the investigated composites were evaluated using UV-Vis spectrophotometry (Cie-Lab). The degree of degradation by changes in the chemical structure of the samples was analyzed using FTIR/ATR spectroscopy. Differential scan-ning calorimetry (DSC) and thermogravimetric analysis (TGA) tests were performed, and the sur-face energy of the samples was determined by measuring the contact angle of droplets. Tests were performed to determine changes in cellulose-filled epoxy resin composites after thermo-oxidative aging and weathering. It was found out that the addition of cellulose did not inflict sufficient changes to the properties within tested parameters. In the tested case, cellulose acted as a natural active biofiller. Our research is in line with the widespread pursuit of pro-ecological solutions in industry and the creation of materials with a positive impact on the natural environment. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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16 pages, 7253 KiB

Open AccessArticle

Analysis of Plastic Improvement and Interference Behavior in Current-Assisted Riveting of CFRP Laminates

by Zhenchao Qi, Ziqin Zhang, Yexin Xiao and Xingxing Wang

Materials 2022, 15(5), 1673; https://doi.org/10.3390/ma15051673 - 23 Feb 2022

Cited by 4 | Viewed by 1606

Abstract

In order to improve the joint performance of a titanium alloy rivet connecting aircraft CFRP structure and promote the wide application of ordinary titanium alloy rivets in the aviation field, the ductility of a Ti45Nb rivet was improved using a current-assisted method in [...] Read more.

In order to improve the joint performance of a titanium alloy rivet connecting aircraft CFRP structure and promote the wide application of ordinary titanium alloy rivets in the aviation field, the ductility of a Ti45Nb rivet was improved using a current-assisted method in this paper. Through experiments, the mechanical behavior and temperature during the riveting process were monitored, and the variation rules of interference and damage were studied in detail. The results show that a current within 16.5 A/mm² can effectively reduce the riveting pressure requirement, and the maximum engineering stress is reduced by nearly 22%. As the current density increases, the softening effect is obvious, but as the processing time increases, the softening effect has an upper threshold. The current-assisted method can significantly increase the interference fit level, and the uniformity of riveting can be improved by nearly 30%. The outlet burr height of a joint obtained by new technology meets the relevant standards. When the current density is too large or the action time is long, the damage pattern and mechanism at different depths of hole have obvious regional differences. Full article

(This article belongs to the Special Issue Advanced Fiber-Reinforced Composites: Design, Properties and Applications)

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