Article
Engineering, Civil
Yuchen Fu, Pedram Sadeghian
Summary: Sandwich composite panels made of bio-based materials show great potential for sustainable building applications. In this study, sandwich beams with flax FRP facings and paper honeycomb core were fabricated and tested under three-point bending. The results showed that the paper honeycomb core has comparable performance to synthetic counterparts, and foam-filling improved the performance of the core and sandwich beams. A new analytical model was developed to predict the test data and conduct a parametric study.
Article
Materials Science, Composites
Limin Bao, Chuanfang Xie, Jian Shi, Yoshihiko Teramoto
Summary: Sandwich-structure materials consist of a high-strength skin material and a lightweight core material, offering excellent mechanical properties and low weight advantages. However, soft-core materials with low rigidity may not perform adequately in sandwich structures. This research aimed to reduce environmental impact and promote sustainable development by developing high-strength carbon foam and enhancing its mechanical properties.
POLYMER COMPOSITES
(2021)
Article
Mechanics
Zhengyi Liu, Hongguang Wang, Lanjie Yang, Jinbo Du
Summary: This study assessed the mechanical properties and durability of flax and glass bio-hybrid fiber reinforced plastics (bio-HFRP) composites in harsh environments. It was found that the addition of glass fiber effectively improved the water absorption of flax fiber composites, resulting in increased flexural strength and decreased flexural modulus.
COMPOSITE STRUCTURES
(2022)
Article
Polymer Science
Yati Mardiyati, Anna Niska Fauza, Steven Steven, Onny Aulia Rachman, Tatacipta Dirgantara, Arief Hariyanto
Summary: Cellulose, as one of the most abundant biopolymers in nature, has gained interest as an alternative material for synthetic polymers. Microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC) are two derivative products of cellulose with excellent mechanical properties. In this study, MCC and NCC were prepared from Cladophora algae and their mechanical properties were studied by adjusting the paper grammage and impregnation with epoxy resin.
Article
Mechanics
S. Alsubari, M. Y. M. Zuhri, S. M. Sapuan, M. R. Ishak
Summary: A novel double cell wall interlocking square core was fabricated from flax fibre reinforced polylactic acid composite. Experimentally, the effect of using double cell walls, different cell sizes, and foam-filled core structure on the compressive strength and specific energy absorption was investigated.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Multidisciplinary
Hui Li, Zelin Li, Zhengyang Xiao, Jian Xiong, Xiangping Wang, Qingkai Han, Jin Zhou, Zhongwei Guan
Summary: In this study, the impact and vibration response characteristics of fiber reinforced polymer sandwich plates with a foam core reinforced by chopped fiber rods are investigated. A dynamic model is proposed to predict the vibro-impact characteristics of the structures. The model is validated through experiments, and the results show that adding fiber reinforcement can reduce the vibro-impact response. The study also suggests that adjusting geometric and material parameters can further reduce the vibration response.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Materials Science, Textiles
Mahadev Bar, Marie Gregoire, Saif Ullah Khan, Emmanuel De Luycker, Pierre Ouagne
Summary: In this study, linseed fibers were extracted from the stems using a fiber extraction device and then refined in a gill drawing mini system. The extracted fibers were found to be suitable for textile yarn manufacturing with high mechanical properties. These fibers can complement textile flax in the production of composite reinforcement fabrics, technical textiles, or garments.
JOURNAL OF NATURAL FIBERS
(2022)
Article
Engineering, Mechanical
Hui Li, Yang Liu, Haiyang Zhang, Zhaoye Qin, Zhaoyang Wang, Yichen Deng, Jian Xiong, Xiangping Wang, Sung Kyu Ha
Summary: The amplitude-dependent damping characteristics of all-composite sandwich (ACS) plates with a hexagon honeycomb core (HHC) filled by soft foam (SF) are investigated. The solutions of nonlinear fundamental frequencies, mode shapes, and damping ratios of HHC-SF-ACS plates are obtained theoretically. It is found that increasing the Young's or shear moduli of foam material and the filling ratio of SF can improve the damping property of the composite plates significantly.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Yanfeng Guo, Xuxiang Han, Xingning Wang, Yungang Fu, Ronghou Xia
Summary: The research found that paper composite sandwich structures collapse layer by layer under stress, with static compression rate having a significant impact on energy absorption. B-corrugation and 3-honeycomb structures show better enhancement of energy absorption indices.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2021)
Article
Mechanics
Cheng Chen, Xue Li, Caiwei Li, Yingwu Zhou, Lili Sui
Summary: This study proposed a novel method to optimize flax fiber reinforced polymer (FRP) production and its application in reinforced concrete (RC) beams, showing that optimized flax FRP stirrups can reduce environmental impact intensity, while partially bonded flax FRP stirrups demonstrate significant improvements in most environmental impact categories.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
Frederic Lachaud, Mathieu Boutin, Christine Espinosa, David Hardy
Summary: This study experimentally and numerically investigates the mechanical behavior of flax fibres fabric reinforced polymer composites in composite laminates and Omega stiffened Sandwich Panels. The research found that the composites exhibited a strong nonlinear mechanical behavior due to the particular structure of flax fibres, making them competitive with conventional glass fibres reinforced polymer composite sandwich panels used in aeronautics.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Manufacturing
Ju Qiu, Dong Wang, Chuanjun Liu, Lin Chen, Hailong Huang, Qin Sun
Summary: This research validates birdstrike numerical models and examines energy absorption and failure of honeycomb sandwich materials in aircraft design. The study discusses ways to avoid breakdown and summarizes bird-strike scenarios for improved design efficiency and safety.
INTERNATIONAL JOURNAL OF CRASHWORTHINESS
(2021)
Article
Materials Science, Composites
Rania F. Khedr, H. H. Elnahas
Summary: Due to high transportation cost and lack of affordable recycling routes, the rate of recycling polystyrene foam is very low. This study examines the feasibility of using waste polystyrene foam to produce wood plastic composite (WPC) through a novel treatment technique. The results show that WPC with 60 parts per hundred parts of resins (phr) of flax fiber and 2 phr of dioctylphthalate (DOP) can create rPS/FF composite with proper tensile, flexural, and compressive strengths.
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
(2023)
Article
Mechanics
Yalcin Boztoprak, Merve Unal, Cagatay Ozada, Eslem Kuzu, Hakki Ozer, Furkan Ergin, Murat Yazici
Summary: The distinctive features of sound insulation structures are flexibility and porosity. A cellular flexible epoxy matrix material was created using a foaming agent, and hollow glass microspheres were added to increase sound wave refraction. Structures with different densities and voids were formed by adjusting the ratios of filling material and foaming agents. An aluminum honeycomb was used for protection and homogeneous distribution of sound waves. The effect of density differences on sound insulation values was analyzed, and the mechanical, thermal, electrical, and flammability properties of the sandwich structures were evaluated.
COMPOSITE STRUCTURES
(2023)
Article
Chemistry, Physical
Zhou Wen, Ming Li
Summary: This study investigates the low-velocity impact response of honeycomb sandwich structures (HSS) using numerical simulation. The choice of construction material significantly affects the impact resistance and structural stability of the HSS. Glass fiber-reinforced PEEK is identified as the more appropriate face sheet material for the composite HSS, enhancing the overall impact resistance.
Article
Materials Science, Characterization & Testing
Koosha Khorramian, Pedram Sadeghian
Summary: This article introduces a new test method for evaluating the compressive characteristics of glass fiber-reinforced polymer (GFRP) composite bars. Through testing, it was found that this method successfully assessed the mechanical properties of GFRP bars and identified different compression failure modes.
JOURNAL OF TESTING AND EVALUATION
(2021)
Article
Engineering, Mechanical
Dillon Betts, Pedram Sadeghian, Amir Fam
Summary: This study investigates the performance of sandwich panels constructed with flax fiber-reinforced polymer faces and foam cores under impact loading. The results show that ultimate impact energy increases with both core density and face thickness. Various failure modes were observed, including compression face crushing, compression face wrinkling, core shear, and tension face rupture. Additionally, a novel nonlinear incremental iterative model was developed to accurately predict total deflection and face strains based on impact energy conservation and nonlinear mechanical behavior of the materials.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2021)
Article
Construction & Building Technology
Krishna Priyanka Garikapati, Pedram Sadeghian
JOURNAL OF BUILDING ENGINEERING
(2020)
Article
Construction & Building Technology
Dillon Betts, Pedram Sadeghian, Amir Fam
Summary: This study experimentally investigated the post-impact residual flexural behavior of sandwich panels with flax fiber-reinforced polymer faces and polyisocyanurate foam cores. Results showed that the panels demonstrated remarkable resilience with no negative impacts on their flexural strength or stiffness after multiple impacts. The panels are suitable for infrastructure applications due to their ability to retain strength and stiffness even after impact events.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Construction & Building Technology
Koosha Khorramian, Pedram Sadeghian
Summary: The study found that the hybrid system is more effective for strengthening slender columns than the wrapping system, controlling second-order deformations due to the slenderness effect and enhancing load-bearing capacity. Further analysis was conducted with an analytical-numerical model considering second-order deformations of slender columns, showing good agreement with experimental data and an independent study.
JOURNAL OF STRUCTURAL ENGINEERING
(2021)
Article
Engineering, Civil
Koosha Khorramian, Pedram Sadeghian
Summary: This study developed a new mechanics-based prediction method for the ultimate condition of FRP-confined concrete using a large database of test data, and proposed a single stress-strain relationship equation for practical applications.
Article
Engineering, Civil
Sarah Hansen, Pedram Sadeghian
Summary: This study successfully reduces the cement content in concrete by using recycled gypsum powder and fly ash, without adversely affecting the strength and durability of the concrete.
CANADIAN JOURNAL OF CIVIL ENGINEERING
(2022)
Article
Construction & Building Technology
Sina Mahmoodi, Pedram Sadeghian
Summary: This study investigated the effects of different exposure conditions on crack widths in engineered cementitious composites (ECC) and found seawater to be a promising environment for the self-healing process in ECC specimens.
STRUCTURAL CONCRETE
(2023)
Article
Engineering, Civil
Koosha Khorramian, Fadi Oudah, Pedram Sadeghian
Summary: The design provisions for internal GFRP-RC columns are being considered for updates by design committees due to advancements in understanding their behavior. This study proposes optimized reliability-based slenderness limits for CSA S806 and CSA S6 using a novel reliability-based approach that incorporates artificial intelligence and a comprehensive experimental database.
CANADIAN JOURNAL OF CIVIL ENGINEERING
(2022)
Article
Engineering, Civil
Akram Jawdhari, Amir Fam, Pedram Sadeghian
Summary: Angle-ply fiber-reinforced polymer (FRP) tubes exhibit nonlinear behavior and increased tensile strength and stiffness when filled with concrete. This is mainly due to matrix cracking and in-plane shear, with concrete filling restraining contraction and generating hoop tensile stresses.
JOURNAL OF COMPOSITES FOR CONSTRUCTION
(2022)
Article
Engineering, Civil
Dillon Betts, Pedram Sadeghian, Amir Fam
Summary: Finite-element modeling was used to investigate the behavior of sandwich panels with bidirectional flax fiber-reinforced polymer (FFRP) faces and foam cores under concentrated loads. Large-scale sandwich panels with different FFRP face thicknesses and foam core densities were tested. The modeling considered material and geometric nonlinearity, and four failure modes were studied. A parametric study was also conducted to examine the effects of foam core density, face and core thickness, and loading area size.
JOURNAL OF COMPOSITES FOR CONSTRUCTION
(2023)
Article
Engineering, Civil
Yuchen Fu, Pedram Sadeghian
Summary: Sandwich composite panels made of bio-based materials show great potential for sustainable building applications. In this study, sandwich beams with flax FRP facings and paper honeycomb core were fabricated and tested under three-point bending. The results showed that the paper honeycomb core has comparable performance to synthetic counterparts, and foam-filling improved the performance of the core and sandwich beams. A new analytical model was developed to predict the test data and conduct a parametric study.
Article
Engineering, Civil
Raghad Kassab, Pedram Sadeghian
Summary: This paper presents experimental and analytical studies on sandwich beams subjected to three-point bending beyond their limit of proportionality. The beams were composed of PET FRP composite facings and R-PET foam core made from post-consumer plastic bottles. The results showed non-linear load-deflection behavior, and a non-linear analytical model was developed. A parametric analysis was performed to evaluate the mechanical performance under different conditions, and a failure mode map was created. This study provides valuable insights into using recycled materials in construction and reducing plastic waste.
Article
Construction & Building Technology
Alireza Jafari, Pedram Sadeghian
Summary: This study examined the effects of biochar and its presoaking on the properties of sustainable mortars. Biochar provides water and enhances hydration in cement matrices, affecting the strength and porosity of the materials. The water retention potential of biochar has a positive impact on early-age compressive strength but weakens over time. The low strength of biochar and its effect on porosity are the main factors reducing the strength of the materials. The influence of presoaking depends on the initial reactivity of binders.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Koosha Khorramian, Pedram Sadeghian, Fadi Oudah
Summary: A reliability-based methodology is employed in this research to quantify the safety associated with the slenderness limit calculation of concrete columns reinforced with GFRP bars. Four alternative design equations are proposed and optimized to achieve a target reliability index.
ACI STRUCTURAL JOURNAL
(2022)
Article
Engineering, Civil
Jian Xue, Weiwei Zhang, Jing Wu, Chao Wang, Hongwei Ma
Summary: This study integrates a plate-type local resonator with varying free boundaries within a plate to convert the initial low-order global vibration modes into localized vibration modes. A novel semi-analytical method is proposed to analyze the free vibration of the plate with thickness and displacement discontinuities. The results show that by applying free boundary conditions, the low-order localized vibration frequencies can be significantly reduced without affecting the low-order global frequencies.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Merve Tunay
Summary: In recent years, there has been an increasing number of studies on the mechanical properties of sandwich structures manufactured with the Fused Deposition Modeling (FDM) method. However, there is still a lack of experimental data on the mechanical characteristics of FDM-manufactured sandwich structures under different thermal aging durations. In this experiment, the energy absorption capabilities of sandwich structures with different core geometries were investigated under various thermal aging durations. The results showed that the core topology significantly influenced the energy absorption abilities of the sandwich structures.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Zi-qin Jiang, Zi-yao Niu, Ai-Lin Zhang, Xue-chun Liu
Summary: This paper proposes a crosssection corrugated plate steel special-shaped column (CCSC) that improves the bearing capacity and overall stability of structural columns by using smaller material input. Through theoretical analysis and numerical simulation, the overall stability of the CCSC under axial compression is analyzed. The design method and suggestions for the stability of CCSC are put forward. Compared with conventional square steel tube columns, the CCSC has obvious advantages in overall stability and steel consumption.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Yong Zhang, Yangang Chen, Jixiang Li, Jiacheng Wu, Liang Qian, Yuanqiang Tan, Kunyuan Li, Guoyao Zeng
Summary: A hybrid TPMS method was proposed to develop a new TPMS structure, and the mechanical properties of different TPMS structures were studied experimentally and numerically. Results showed that the hybrid TPMS structure had higher energy absorption and lower load-carrying capacity fluctuation. Further investigations revealed that the topological shape and material distribution had significant influence on mechanical properties, and the hybrid additive TPMS structure exhibited significant crashworthiness advantage in in-plane crushing condition.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Tongfei Sun, Ye Liu, Kaoshan Dai, Alfredo Camara, Yujie Lu, Lijie Wang
Summary: This paper presents a series of experimental and numerical studies on the performance of a novel double-stage coupling damper (DSCD). The effects of damper configuration, friction-yield ratio (Rfy), and loading protocol on the hysteresis performance of the DSCD are investigated. The test results demonstrate that the arrangement of ribs in the DSCD increases its energy dissipation capacity. Numerical analysis reveals that the length of the friction mechanism and the clearance between the yield segment and the restraining system affect the energy dissipation and stability of the damper.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Jeonghwa Lee, Young Jong Kang
Summary: This study investigates the local buckling behavior and strength of I-shape structural sections by considering flange-web interactions through three-dimensional finite element analysis. The study provides a more reasonable estimation of local buckling strength by considering the ratio of flange-web slenderness and height-to-width ratio, and presents design equations for flange local and web-bend buckling coefficients.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Yizhe Chen, Wenfeng Xiang, Qingsong Zhang, Hui Wang, Lin Hua
Summary: This study investigates the surface modification of a nickel plate to improve the bonding strength with carbon fiber-reinforced plastics (CFRP). The results show that different surface modification methods, including sandblasting, coupling agent treatment, and compound coupling agent treatment, significantly enhance the bonding strength of CFRP/Ni joints. The research provides insights into improving the connection between nickel and CFRP, as well as other heterogeneous materials.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Agha Intizar Mehdi, Fengping Zhang, Moon-Young Kim
Summary: A spatial stability theory of mono-symmetric thin-walled steel beams pre-stressed by spatially inclined cables is derived and its validity is demonstrated through numerical examples. The effects of initial tension, deviator numbers, inclined cable profiles, and bonded/un-bonded conditions on lateral-torsional buckling of the pre-stressed beams are investigated, with a specific emphasis on the effects of increasing initial tension.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Teng Ma, Jinxiang Wang, Liangtao Liu, Heng Li, Kui Tang, Yangchen Gu, Yifan Zhang
Summary: The structural response of water-back plate under the combined action of shock wave and bubble loads at water depths of 1-300 m was numerically investigated using an arbitrary Lagrange-Euler method. The accuracy of the numerical model was validated by comparing with experimental and theoretical results. The influences of water depth and length-to-diameter ratio of the charge on the combined damage effect were analyzed. The results show that as water depth increases, the plastic deformation energy of the water-back plate decreases, and the permanent deformation mode changes from convex to concave. When the charge has a large length-to-diameter ratio, the plastic deformation energy of the radial plate is higher than that of the axial plate, and the difference decreases with increasing water depth. Increasing the length-to-diameter ratio enhances the combined damage effect in the radial direction in deep-water environments.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Qiu-Yun Li, Ben Young
Summary: This paper investigates the flexural performance of CFS zed section members bent about the neutral axis parallel to the flanges through experimental and numerical analysis. The results show that the current direct strength method generally provides conservative predictions for the flexural strength of unstiffened zed section members, but slightly unconservative design for edge-stiffened zed section beams. The nominal flexural strengths of zed section members with edge stiffeners were found to be underestimated by 17% to 21% on average. Modified DSM formulae are recommended for the design of CFS zed section beams.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Weinan Gao, Bo Song, Xueyan Chen, Guochang Lin, Huifeng Tan
Summary: This paper presents a precise method for predicting deformation in large-scale inflatable structures, utilizing finite element modeling and laser scanning technique. The study shows a good agreement between the predictive model and non-contact measurement results.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Fei Gao, Zongyi Wang, Rui Zhu, Zhenming Chen, Quanxi Ye, Yaqi Duan, Yunlong Jia, Qin Zhang
Summary: This research investigates the mechanical properties of high-strength ring groove rivet assemblies and the load resistances of riveted T-stubs. Experimental tests reveal that Grade 10.9 rivets have higher yield strength and strain, and lower ultimate strain, making them suitable for high-strength ring groove rivet connections. Increasing the rivet diameter benefits the T-stubs, while increasing the flange thickness is not always advantageous. The Eurocode 3 method is not suitable for T-stubs connected through ring groove rivets, while the Demonceau method is conservative.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Shangchun Jiang, Liangfeng Sun, Haifei Zhan, Zhuoqun Zheng, Xijian Peng, Chaofeng Lue
Summary: This study investigates the bending behavior of two-dimensional nanomaterials, diamane and its analogous structure TBGIB, through atomistic simulations. It reveals that diamane experiences structural failure under bending, while TBGIB bends elastically before undergoing structural failure. The study provides valuable insights for the application of these materials in flexible electronics.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Qiang Zhang, Jianian Wen, Qiang Han, Hanqing Zhuge, Yulong Zhou
Summary: In this study, the mechanical properties of Q690 steel H-section columns under bi-directional cyclic loads are investigated, considering the time-varying characteristics of corrosion. A refined finite element (FE) model is built to analyze the degradation of mechanical property and failure mechanisms of steel columns with different design parameters during the whole life-cycle. The study proposes a quantitative calculation method for the ultimate resistance and damage index of steel columns, taking into account the ageing effects. The findings emphasize the importance of considering the ageing effects of steel columns in seismic design.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Yuda Hu, Qi Zhou, Tao Yang
Summary: The magneto-thermo-elastic coupled free vibration of functionally graded materials cylindrical shell is investigated in this study. The vibration equation in multi-physical field is established and solved using the Hamilton principle and the multi-scale method. The numerical results show that the natural frequency is influenced by various factors such as volume fraction index, initial amplitude, temperature, and magnetic induction intensity.
THIN-WALLED STRUCTURES
(2024)