Article
Engineering, Manufacturing
Mazin Y. Abbood, Riyah N. Kiter
Summary: This study addresses the importance of the axial crushing of thin-walled metal circular tubes, particularly when it fails in concertina mode. Theoretical estimates of the peak load were formulated, and numerical simulations were conducted to validate these estimates. The results show that the peak load is unique for each specimen, while the lower bound stress can be equal for different values of D, t, and L as long as the D/t ratio is the same. The upper bound stress requires consideration of both the D/t and L/D ratios. The numerical results agree well with the theoretical predictions, but not all experimental findings. The disagreement is attributed to questionable data extracted from one of the cited works.
INTERNATIONAL JOURNAL OF CRASHWORTHINESS
(2022)
Article
Engineering, Marine
F. Djamaluddin, F. Mat
Summary: This research analyzed the energy absorption characteristics and crashworthiness design of ship fender structures with varying geometric dimensions. The study focused on foam-filled fenders and used non-linear finite element analysis to determine specific energy absorption and maximum crushing force efficiency, aiming to optimize crashworthiness. The optimization results showed that foam-filled double fender (FDF) had the best performance, recommending a change in traditional fender design.
Article
Polymer Science
Fei Ge, Yuan Lin, Fukai Zhang, Zhongwei Zhang, Mingyang Wang
Summary: This study experimentally investigated the axial crushing characteristics of hybrid tubes with aluminum/CFRP and aluminum/CFRP/aluminum configurations. The results showed that hybrid tubes with [0 degrees/90 degrees] fiber lay-up sequence exhibited better energy absorption performance. Selecting an appropriate tube length-to-diameter ratio is important to achieve a stable and controllable progressive crushing failure mode. The hybrid effect of the energy absorption of hybrid tubes was better than that of individual tubes.
Article
Chemistry, Multidisciplinary
Kadir Gunaydin, Aykut Tamer, Halit Suleyman Turkmen, Giuseppe Sala, Antonio Mattia Grande
Summary: The research investigated the energy absorption characteristics of chiral auxetic lattices filled cylindrical composite tubes under uniaxial and lateral quasi-static loads, finding that the energy absorption capability for axial quasi-static crushing decreased compared to hollow composite design, while the average energy absorption value in lateral loading significantly increased.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Multidisciplinary
Jorge Jimenez-Armendariz, Moises Jimenez-Martinez, Julio Varela-Soriano, Alfredo Santana Diaz, Rogelio Perez Santiago
Summary: To withstand dynamic loads in lightweight structures, it is important to reduce the weight of components while maintaining or improving their mechanical properties. This study implemented heat treatment and a trigger mechanism to enhance energy absorption and reduce peak crushing force in an aluminum thin-walled tube. Experimental designs and quasi-static crushing tests were conducted to analyze the performance of different designs and components. The results showed that specific geometries and heat treatment methods significantly reduced the peak crushing force and increased energy absorption, and the combined mechanism achieved even better results.
Article
Mechanics
Holger Boehm, Jonas Richter, Jinbong Kim, Geunsu Joo, Hong-Kyu Jang, Mungyu Jeong, Andreas Hornig, Maik Gude
Summary: Thermoplastic composite materials were experimentally and numerically investigated for their suitability in energy absorbing lightweight structures. Various specimen configurations were examined, and a stable progressive crushing behavior with promising force-displacement responses was observed. The study also utilized a high-fidelity multi-layered solid modeling approach for numerical analysis on a structural scale to predict damage initiation and failure progression.
COMPOSITE STRUCTURES
(2023)
Article
Materials Science, Composites
Yi-bin Zha, Shun Wang, Qi-hua Ma, Hui Zhang, Xue-hui Zhang, Tian-jun Zhou
Summary: This article investigates the crashworthiness of induced metal-composite thin-walled tubes under axial impact using a combination of experimental and numerical simulation methods. The study explores the effects of different induced designs and structural parameters on the crashworthiness of Al-CFRP hybrid tubes. A new multi-row induced structure is proposed, which improves the crashworthiness of the tubes. The results provide insights into the optimal design parameters and configurations for metal-composite hybrid thin-walled tubes.
POLYMER COMPOSITES
(2022)
Article
Mechanics
Jiacheng Wu, Yong Zhang, Jixiang Li, Xiongming Lai, Nian Duan
Summary: This paper proposes a novel nested corrugated-elliptical tube (NCET) system for energy absorption. The crushing characteristics of the NCET are investigated through experiments and finite element analysis. The results show that the NCET exhibits a low initial stiffness, stable deformation process, and high energy absorption. Compared to single-walled tubes and typical nested energy absorbers, the NCET has higher specific energy absorption and lower initial peak crushing force. The study also analyzes the influence of different parameters on the crushing behavior of the NCET.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
Zhipeng Gao, Hai Zhang, Jian Zhao, Ying Zhang, Dong Ruan
Summary: In this study, thin-walled aluminum square tubes with different wall thickness configurations were experimentally compressed at various loading angles. Numerical analysis was also conducted to investigate the effects of wall thickness, thickness configuration, and loading angle on the deformation mode and energy absorption of the tubes. The results showed that tubes with opposite walls of different thicknesses exhibited better energy absorption performance under oblique loading, while tubes with opposite walls of the same thickness absorbed the most energy at larger angles.
THIN-WALLED STRUCTURES
(2023)
Article
Engineering, Civil
Erhan Cetin, Adil Baykasoglu, Muhammed Emin Erdin, Cengiz Baykasoglu
Summary: This study investigates the behavior of filament-wound aluminum/carbon fiber reinforced plastic (Al/CFRP) hybrid tubes with circular-hole triggering mechanism during axial crushing. Experimental results show that the intact hybrid tube has higher crush energy absorption and efficiency compared to individual components of the structure.
THIN-WALLED STRUCTURES
(2023)
Article
Mechanics
Jianxun Zhang, Haoyuan Guo
Summary: In this paper, the plastic behavior of a clamped rectangular sandwich tube with metal foam core is studied using analytical and numerical methods. The analytical solution for the plastic behavior of the tube under transverse loading is derived using the yield criterion, and is compared with numerical results. The influences of the punch width, loading position, foam strength, and tube-wall thickness on the large deflection of the sandwich tubes are discussed based on the analytical model.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
Chengqing Liu, Dibing Xu
Summary: This study analyzed the relationship between the stiffness ratio of the inner and outer tube of the diagrid core-tube structure in high-rise buildings and the redistribution of the storey shear force, structural ductility, overstrength factor, and seismic performance. The results showed that there is a significant redistribution of floor shear force in the diagrid core-tube structure under different earthquake actions, and the storey shear coefficient decreases with increasing earthquake level and equivalent stiffness ratio. The diagonal angle is the main factor affecting the weak floor location and shear lag effect. The structural ductility is generally optimal at a diagonal angle of 77 degrees. The overstrength factor increases with increasing equivalent stiffness ratio in structures with the same diagonal angle.
KSCE JOURNAL OF CIVIL ENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Suphassa Pringpromsuk, Hong Xia, Qing-Qing Ni
Summary: A tube actuator was successfully fabricated by incorporating SMPU with DBA plasticizer, producing softness and glass transition temperature close to human body temperature. The addition of DBA plasticizer to SMPU resulted in a faster recovery rate and a shape recovery ratio of up to 83%. The biocompatibility and non-toxicity of the tube make it a promising candidate for clinical applications.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Materials Science, Multidisciplinary
Mehrdad Koloushani, Mohammad Reza Forouzan, Mohammad Reza Niroomand
Summary: In this study, the effects of diameter and thickness of thin-walled Aluminum tubes on crashworthiness criteria were investigated. The optimal diameter for a simple circular tube was found to be the smallest diameter in terms of resistance to global buckling. Increasing thickness and the ratio of thickness to diameter were found to improve the energy absorption and crushing force efficiency. Two equations were presented for predicting the maximum crushing force and crushing force efficiency of thin-walled metal tubes.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Nursing
Kersti Teder, Liisa Johvik, Andres Meos, Marika Saar, Alesya Visbek, Daisy Volmer, Juri Karjagin
Summary: This study investigated the administration of solid medications through feeding tubes in the Tartu University Hospital intensive care units and found that almost half of the medications lacked information on suitability, potentially increasing the risk of errors for patients.
NURSING IN CRITICAL CARE
(2022)
Article
Construction & Building Technology
Markos Tsegaye Beyene, Felicite Kingne, Eleni Tsangouri, Michael El Kadi, Tamene Adugna Demissie, Hubert Rahier, Danny Van Hemelrijck, Tine Tysmans
Summary: Researchers investigated the effects of replacing Portland cement with supplementary cementitious materials (SCM) on the durability of Ensete ventricosum (Ev) fibres in cementitious matrices. The flexure tests showed that composites with 100% Portland cement matrix lost ductility and strength after 25 wet-dry cycles, while ternary matrices of 70% FA and 10% MK exhibited minimal degradation. Partial replacement of Portland cement by SCMs can reduce the degradation of natural fibres in cement-based composites.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Physical
Efstratios Polyzos, Hendrik Pulju, Peter Maeckel, Michael Hinderdael, Julien Ertveldt, Danny Van Hemelrijck, Lincy Pyl
Summary: This article presents a novel approach that utilizes machine learning and polynomial chaos expansion to assess the effects of residual stresses in laser-directed energy deposition (L-DED). The approach involves measuring the thermal expansion coefficient of thin-wall L-DED steel specimens and using it to predict the displacement field in incremental hole-drilling tests. Experimental measurements from 3D micro-digital image correlation setup show good agreement with the predictions.
Article
Polymer Science
Efstratios Polyzos, Danny Van Hemelrijck, Lincy Pyl
Summary: This article introduces the development and implementation of the Delamination Plug-in, an open-source tool for modeling delamination tests in the ABAQUS software. The plug-in combines the benefits of GUI and FE programming and provides algorithms for various delamination tests. It is demonstrated to be efficient and applicable for both conventional and 3D printed composite laminates.
Article
Polymer Science
Pei Hao, Siebe W. F. Spronk, Ruben D. B. Sevenois, Wim van Paepegem, Francisco A. Gilabert
Summary: The nonlinear behaviour of FRPC in transverse loading is mainly induced by the constituent polymer matrix, which is rate- and temperature-dependent. This paper presents a test setup to provide robust stress-strain measurements for FRPC at high strain rates. The micro- and macroscopic thermomechanical response of CF/PR520 and CF/PEEK systems are analyzed, showing excessive strain localization and discussing the differences between thermoplastic and thermoset matrices.
Article
Construction & Building Technology
Gerlinde Lefever, Ahmad Shawki Charkieh, Mustafa Abbass, Danny Van Hemelrijck, Didier Snoeck, Dimitrios G. Aggelis
Summary: The inclusion of superabsorbent polymers (SAPs) is increasingly attractive to promote the self-healing ability of cementitious materials and reduce manual repair costs. Ultrasonic monitoring is used for non-destructive evaluation to determine the effectiveness and compare the healing capacity of different mixtures. However, previous studies mainly focused on mortars without large aggregates, so monitoring and comparing the self-healing of concrete and mortar were conducted. Ultrasonic surface wave monitoring shows the potential to evaluate crack closure and the effects of different SAPs.
DEVELOPMENTS IN THE BUILT ENVIRONMENT
(2023)
Article
Engineering, Manufacturing
Amalia Katalagarianakis, Efstratios Polyzos, Danny Van Hemelrijck, Lincy Pyl
Summary: This study experimentally investigates the delamination behavior of carbon fiber-reinforced polyamide laminates under different loading modes. The interlaminar fracture toughness at crack initiation was found to be 1.5 kJ/m2 in mode I, 2.1 kJ/m2 in mode II, and 1.0 kJ/m2 in mixed mode I-II. Various analytical and numerical models were used to validate the experimental results, and scanning electron microscopy revealed the micro-mechanical origins of the crack in different loading configurations.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Engineering, Multidisciplinary
E. Polyzos, D. Van Hemelrijck, L. Pyl
Summary: This study presents a new stochastic modeling approach to address challenges in micromechanical modeling of short-fiber composites. It introduces a stochastic generation technique based on kernel density estimation to save time and effort in fiber extraction, and a novel semi-analytical approach to consider multiple fibers while reducing computational effort. The approach is demonstrated on recycled poly(ethylene terephthalate) filaments reinforced with recycled short carbon fibers for additive manufacturing, showing similar predictions of elastic properties using only 40-50 fibers compared to a direct modeling approach with 1050 fibers, and close agreement with experimental data.
COMPOSITES PART B-ENGINEERING
(2023)
Article
Mechanics
Ali Shivaie Kojouri, Haniyeh Khosravi Rikaee, Kalliopi-Artemi Kalteremidou, Danny Van Hemelrijck
Summary: This study examines the capability of the digital image correlation method to determine the Jintegral for polymers with elastic and elastic-plastic behavior. To achieve this, single-edge notch tension specimens manufactured out of PMMA and HDPE are tested under pure mode I loading conditions, and the displacement field at the surface of each specimen is obtained using DIC. The J-integral for each specimen is then computed by combining the higher-order singular and non-singular terms derived from DIC.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Mechanics
E. Polyzos, D. Van Hemelrijck, L. Pyl
Summary: This article presents a new analytical solution to the delamination problem of interface deformable generally layered composite laminates. The governing equation for interface forces and moments is obtained under plane strain assumptions, considering extension-bending coupling phenomena and residual hygrothermal stresses. The interface forces and moments are included in a novel generalization of the J-integral to estimate the Energy Release Rate (ERR). The analytical results of ERR and mode mixity show excellent agreement with Finite Element models for a Double Cantilever Beam test of a generally layered fibre metal laminate, utilizing the Cohesive Zone Method (CZM) and the Virtual Crack Closure Technique (VCCT).
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Mechanics
E. Polyzos, D. Van Hemelrijck, L. Pyl
Summary: A novel approach is proposed in this study to convert real voids to ideal supercylindrical ones, which better approximate the shape of voids and can be described by a single parameter. The elastic properties of acrylonitrile butadiene styrene are predicted using the polynomial chaos expansion technique. The results are compared with previous tensile tests and different modeling approaches to gain a comprehensive understanding of the advantages of the new approach.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
E. Polyzos, D. Polyzos, D. Van Hemelrijck, L. Pyl
Summary: The majority of studies in the open literature use homogenization models to consider microstructural parameters, but they fail to account for size effects at small scales. This study introduces a novel approach that combines property contribution tensors with strain gradient elasticity to capture size effects and improve predictions about effective elastic properties.
MECHANICS OF MATERIALS
(2023)
Article
Engineering, Manufacturing
E. Polyzos, C. Nikolaou, D. Polyzos, D. Van Hemelrijck, L. Pyl
Summary: This study introduces a new method for creating accurate microscale finite element models of 3D printed composites. It utilizes micro-CT and neural network algorithms to differentiate and predict the distribution of fibers in the microstructure, and uses finite element analysis to determine the elastic properties of the composite material. The results show that this method is accurate and reliable, and also reveal the transversely isotropic behavior of the printed composites.
ADDITIVE MANUFACTURING
(2023)
Proceedings Paper
Construction & Building Technology
Gerlinde Lefever, Nele De Belie, Danny Van Hemelrijck, Dimitrios G. Aggelis, Didier Snoeck
Summary: This study evaluates the closure of cracks in cementitious mixtures with and without superabsorbent polymers using ultrasound measurements. By sending ultrasonic waves through the cracks, information on both the sound material and the healing products formed within the cracks is obtained. The healing process is promoted by wet-dry curing cycles and monitored for 14 days. Ultrasound was found to be sensitive to the closure of cracks, as confirmed by microscopic analysis of the reduction in crack width opening.
PROCEEDINGS OF THE 75TH RILEM ANNUAL WEEK 2021
(2023)
Article
Engineering, Mechanical
E. Polyzos, E. Vereroudakis, S. Malefaki, D. Vlassopoulos, D. Van Hemelrijck, L. Pyl
Summary: This research investigates the elastic and damage characteristics of individual composite beads used in 3D printed composites. A new analytical probabilistic progressive damage model (PPDM) is introduced to capture the elastic and damage attributes of these beads. Experimental results show strong agreement with the model in terms of elastic behavior and ultimate strength and strain.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Construction & Building Technology
Gerlinde Lefever, Ahmad Shawki Charkieh, Danny Van Hemelrijck, Didier Snoeck, Dimitrios G. Aggelis
Summary: Non-destructive evaluation using air-coupled ultrasound provides an efficient method for assessing the self-healing ability of cementitious composites.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
