Article
Mathematics, Applied
Tadanobu Inoue, Rintaro Ueji
Summary: This study investigated the formation of cube texture in low carbon steel bars through finite element analysis, revealing that cube texture can be successfully formed in the center area. The accumulation of equivalent strain in the center was more than twice as large as the nominal strain calculated from shape change. Cube texture was found to be induced by a bi-axial simple compressive mode, with the center to quarter area showing the formation of cube texture under simple compressive mode.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Z. Liu, J. Reinoso, M. Paggi
Summary: A three-dimensional hygro-thermo-mechanical computational framework for photovoltaic laminates has been established and successfully implemented in this study. The method takes into account the thermal properties in thin-walled structures and the characteristics of polymeric interfaces, showing efficiency and reliability.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Engineering, Mechanical
Qiang Guo, Yue Zheng, Shengqiang Cai
Summary: In this work, a theoretical framework is formulated to model the complex behaviors of LCEs with thermo-electro-mechanical coupling. Analytical solutions for homogeneous deformation are derived. A numerical approach that employs a quasi-convexified free energy function and achieves a key transformation of reference configuration is proposed for finite element simulation. The effectiveness of the model and numerical approach are validated through various simulations, demonstrating their potential applications.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Chemistry, Physical
Fatih Sikan, Priti Wanjara, Javad Gholipour, Amit Kumar, Mathieu Brochu
Summary: The research aimed to develop a finite element model for electron beam additive manufacturing of Ti-6Al-4V, which was validated with fabricated samples and thermocouple measurements. The model showed reliability in predicting temperatures, residual stresses, and distortion profiles, with low average error in thermal predictions. The model successfully predicted cooling rates, grain morphology, and microstructure, with maximum deviations in mechanical predictions as low as 100 MPa in residual stresses and 0.05 mm in distortion.
Article
Computer Science, Interdisciplinary Applications
Ioannis S. Pressas, Spyros Papaefthymiou, Dimitrios E. Manolakos
Summary: This study focuses on the investigation of the effects of roll elasticity and thermal deformations on the dimensional accuracy of ring products in a ring rolling process. The results show that these two factors can cause significant deviations in the ring dimensions, while the effects of tool elasticity and thermal expansion can be neglected.
SIMULATION MODELLING PRACTICE AND THEORY
(2022)
Article
Engineering, Multidisciplinary
Zeng Liu, Pietro Lenarda, Jose Reinoso, Marco Paggi
Summary: A comprehensive coupled thermo-chemo-mechanical modeling framework is proposed to study the reaction-diffusion phenomena in photovoltaics. The model accurately predicts the chemical degradation of ethylene-co-vinyl acetate (EVA) layers under hygrothermal conditions, considering the spatial and temporal variation of diffusivity and chemical kinetic rates. The framework successfully reproduces the evolution of reaction-diffusion species and demonstrates its capability to predict spatio-temporal variation under cyclic temperature boundary conditions.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Behrouz Arash, Wibke Exner, Raimund Rolfes
Summary: A finite deformation phase-field fracture model was developed to analyze the thermo-viscoelastic behavior of boehmite nanoparticle/epoxy nanocomposites, considering rate-dependent fracture evolution and the effect of nanoparticle contents and temperature on fracture behavior. The model's predictive capability was validated through comparing numerical results with experimental data, and numerical simulations were performed to study the effect of temperature and deformation rate on the force-displacement response of the nanocomposites in compact-tension tests.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Hojin Jeon, Jaehyun Noh, Minjae Kim, Minho Jo, Sang-Hoon Nam, Jeongdai Jo, Changwoo Lee
Summary: This research presents the development of a feedforward tension controller that employs Finite Element Method (FEM)-based web temperature distribution inputs to enhance tension control performance during the drying span in roll-to-roll manufacturing system. The experimental results demonstrate that the proposed model improves tension control accuracy during the drying process by 27.76% compared to the existing control logic. Furthermore, the effectiveness of the tension control logic in enhancing the surface quality of functional layers was confirmed through surface quality analysis using solid oxide fuel cell (SOFC) electrolyte layers.
ENGINEERING SCIENCE AND TECHNOLOGY-AN INTERNATIONAL JOURNAL-JESTECH
(2023)
Article
Automation & Control Systems
Steven Hill, Richard P. Turner
Summary: In a series of ring compression tests on BS970:708M40 alloy steel, it was found that temperature variation had a greater impact on deformation than lubricant agents. Additionally, graphite-molybdenum disulphide grease significantly outperformed other lubricants in reducing friction and enabling deformation in high-temperature forgings.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Mechanics
Hukum Chand Dewangan, Subrata Kumar Panda, Nitin Sharma, Samy Refahy Mahmoud, Dineshkumar Harursampath, Vinyas Mahesh
Summary: This work presents a numerical modeling study on the static large-deformation behavior of multilayered flat/curved panels with cutouts under thermo-mechanical load. The numerical model incorporates third order displacement polynomials and two nonlinear strains (Green-Lagrange and von-Karman) to capture the large-deformation characteristic of the panel. The governing equation is formulated using Hamilton's principle and solved using the selective integration scheme and Picard's direct iterative method.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2023)
Article
Mechanics
Rishu Gupta, S. Mustafa Kazim, Kartik Prasad, Pritam Chakraborty
Summary: A crystal plasticity model was developed to study the fatigue behavior of Ti-6Al-4V under different thermo-mechanical loading conditions, and was calibrated and validated using experimental data. The simulations under in-phase and out-of-phase thermo-mechanical fatigue loads successfully captured the differences in stress range and hysteresis between the two cases, with the stress distribution in the microstructure explaining the observed longer life under in-phase loading compared to out-of-phase loading.
MECHANICS RESEARCH COMMUNICATIONS
(2021)
Article
Engineering, Civil
Emin Kocbay, Jakob Scheidl, Fabian Riegler, Martin Leonhartsberger, Matthias Lamprecht, Yury Vetyukov
Summary: We propose a nonlinear shell finite element model to simulate the continuous forming process of sheet metal roll forming. A mixed Eulerian-Lagrangian kinematic description is employed, and the finite element mesh is detached from the particle motion to facilitate a two-step solution procedure. The continuum plasticity model guarantees a precise resolution of the forming process in each cross section of the Kirchhoff-Love shell, and the numerical scheme is validated through simulations and a physical experiment.
THIN-WALLED STRUCTURES
(2023)
Article
Metallurgy & Metallurgical Engineering
Zhang Lu, Yu Zhiwei, Zhang Leicheng, Jiang Rong, Song Yingdong
Summary: Under complex cyclic force/thermal multifield coupled service conditions, thermo-mechanical fatigue (TMF) failure is a common failure type of aeroengine turbine disks. In this study, in-phase (IP) and out-of-phase (OP) TMF tests were conducted on the GH4169 superalloy. The results showed that the TMF stress-strain curves exhibited tensile-compression stress asymmetry, and cyclic softening was observed in the high-temperature half-cycle. The TMF life was shorter than the isothermal fatigue life at the peak temperature under the same strain amplitude. Fracture analysis revealed transgranular fracture for OP TMF cracks and intergranular fracture for IP TMF cracks.
ACTA METALLURGICA SINICA
(2023)
Article
Materials Science, Multidisciplinary
Hui Su, Longgang Hou, Qingkun Tian, Yawen Wang, Linzhong Zhuang
Summary: The bending behavior and mechanism during the asymmetric rolling (ASR) process of high-strength AA7050 aluminium alloy plates were investigated. It was found that the plate bends upward at larger speed ratios and smaller thickness reductions, and bends downward at smaller speed ratios and larger thickness reductions. The ASR process increases the central equivalent plastic strains and decreases the surface-to-center strain gradient, leading to improved strain uniformity.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Manufacturing
Lianjie Li, Jianxin Li, Haibo Xie, Hongqiang Liu, Li Sun, Tianwu Liu, Xu Liu, Kexin Shi, Zhengyi Jiang
Summary: A novel three-dimensional finite element model is proposed to simulate strip deformation during hot strip tandem rolling, utilizing segmentation modeling strategy and data transfer technology to integrate sub-models into a whole model.
INTERNATIONAL JOURNAL OF MATERIAL FORMING
(2021)
Correction
Engineering, Environmental
Rui Liu, Mark Vail, Behrad Koohbor, Cheng Zhu, Chao-Sheng Tang, Hao Xu, Xiang-Chao Shi
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Materials Science, Multidisciplinary
Nicholas Pagliocca, Kazi Zahir Uddin, Ibnaj Anamika Anni, Chen Shen, George Youssef, Behrad Koohbor
Summary: This research focuses on the design, fabrication, and mechanical characterization of flexible, planar mechanical metamaterials with tunable properties. By introducing different geometric perforations, the structures exhibit adjustable mechanical behavior and a wide range of Poisson's ratios. The study highlights the correlation between perforation configurations and auxetic response, and proposes a practical strategy for activating a self-strengthening mechanism in the structures. It also demonstrates the feasibility of fabricating planar flexible structures with controllable Poisson's ratios through spatial adjustment of perforations.
MATERIALS & DESIGN
(2022)
Article
Chemistry, Physical
Bertan Ozdogru, Shubhankar Padwal, Batuhan Bal, Sandip Harimkar, Behrad Koohbor, Omer Ozgur Capraz
Summary: In this study, an in operando experimental system was established using digital image correlation to investigate the chemo-mechanical deformations at the interface between the solid electrolyte and Li metal electrode in high-energy all-solid-state batteries. The study found a correlation between overpotentials and mechanical deformations, and detected fractures in the middle of the solid electrolyte during later cycles.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Engineering, Manufacturing
P. J. Centellas, M. Yourdkhani, S. Vyas, B. Koohbor, P. H. Geubelle, N. R. Sottos
Summary: This study investigates the impact of multiple polymerization fronts on the manufacturing of composites. It finds that localized void formation, panel thickness increase, and thermal spike between two merging fronts have a detrimental effect on composite performance. By modifying the layup from thermally insulated boundaries to thermally conductive boundaries, all adverse phenomena at the merging fronts are successfully mitigated, leading to improved composite mechanical properties.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2022)
Article
Engineering, Mechanical
J. Mahon, N. Pagliocca, V Harnack, B. Koohbor, R. Krchnavek, W. Xue
Summary: In this study, a novel tensile testing apparatus for thin film samples in cryogenic temperature conditions is developed and validated using finite element analysis and digital image correlation. The results demonstrate the accuracy and reliability of this apparatus for mechanical characterization of thin films in cryogenic conditions.
EXPERIMENTAL TECHNIQUES
(2023)
Article
Materials Science, Multidisciplinary
Kazi Zahir Uddin, Nicholas Pagliocca, Ibnaj Anamika Anni, George Youssef, Behrad Koohbor
Summary: This study investigates the relationships between global and local strain fields in rectangular center-symmetric perforated planar structures, highlighting the role of local morphology on the macroscopic material response.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jeeva Muthulingam, Anuraag Gangineri Padmanaban, Nand K. Singh, Tristan W. Bacha, Joseph F. Stanzione III, Francis M. Haas, Ratneshwar Jha, Jae-Hwang Lee, Behrad Koohbor
Summary: Polymer cold spray is a novel manufacturing process that allows for the deposition of uniform polymer coatings without the need for solvents or high temperatures. This study investigates the interplay between shear instability and fracture in the deposition of glassy thermoplastics, using a hybrid experimental-computational approach. The results demonstrate that the adhesion mechanisms depend strongly on the molecular weight of the sprayed particles, and the fracture of the sprayed glassy polymers also significantly affects the deposition process.
Article
Mechanics
H. Girard, A. Doitrand, B. Koohbor, R. G. Rinaldi, N. Godin, D. Long, J. Bikard, L. Trouillet-Fonti
Summary: Fiber-matrix interface debonding was investigated in single-fiber epoxy-glass fiber specimens subjected to transverse tensile loading. Experimental observations showed sudden debonding initiation between 67 and 83 deg., followed by stable debonding propagation. A coupled criterion (CC) accurately predicted the abrupt debonding initiation, considering stress and energy aspects. This method allowed for obtaining a range of interface shear and opening critical energy release rates (ERR) and strengths. The loading required for initiation depended on the opening (mode I) critical ERR and tensile and shear strengths. The debonding arrest angle also depended on the shear (mode II) critical ERR. Thus, a three-step methodology was described to determine the interface properties and an optimum set of parameters using Linear Elastic Fracture Mechanics.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Lalith Kumar Bhaskar, Jared Rapp, Ankush Nandi, Agni Kumar Biswal, Kazi Zahir Uddin, Behrad Koohbor, Ravi Kumar, Aniruddh Vashisth
Summary: Entropy stabilized oxides (ESOs) are a new class of stable hybrids and single phase metal oxides with material properties in between the constituent oxides. However, their energy-intensive fabrication process has limited their development and scale-up. In this work, a novel energy-efficient ESO synthesis method using carbonaceous materials and radio frequency (RF) fields is proposed, enabling the synthesis of ESOs in less than a minute. The synthesized ESO-carbon composites show promising properties, and this method provides a rapid and efficient manufacturing process.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Ibnaj Anamika Anni, Madison S. Kaminskyj, Kazi Zahir Uddin, Tristan W. Bacha, Nand K. Singh, Joseph F. Stanzione, Francis M. Haas, Behrad Koohbor
Summary: This study investigates the deposition of nylon 6 on fiber-reinforced composite substrates using cold spray coating. The deposition conditions are systematically varied, and optimal system pressure and powder flow rates are identified for successful deposition. It is observed that the particles undergo extensive plastic deformation upon impact, but without damaging the reinforcing fibers in the substrate. This work demonstrates the feasibility of cold spray deposition of thermoplastic particles on fiber-reinforced composites without significant substrate damage.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Mark Smeets, Behrad Koohbor, George Youssef
Summary: This research explores the density gradation of foam structures as a means to enhance the mechanical efficiency of protective padding. Adhesive-free, discrete density gradation of foam sheets is achieved by utilizing the properties of frothed foam slurry to naturally bond and penetrate cured foam sheets. Compared to monolayer, mono-density foam, the seamless, graded foam samples demonstrated improved mechanical performance. Irrespective of gradation and interface type, polyurea foam outperformed benchmark foam in terms of specific energy absorption, efficiency, and ideality. The study also highlights the fabrication method for adhesive-free density-graded foam structures, the use of diverse key performance indicators (KPIs) to assess foam efficacy, and the superiority of polyurea foam-based lightweight protective paddings. Future research will focus on the dynamic performance of graded foam structures under impact loading at various velocities.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Nicholas Pagliocca, Mitja Trkov, Behrad Koohbor
Summary: This paper focuses on mechanical metamaterials and develops modular soft robotic actuators using soft elastomers and flexible thermoplastic sheets. The results demonstrate the influence of perforation geometry on the reinforcement structure's spatial stiffness and the actuators' response. The study also extends the concept of spatial stiffness to develop soft robotic actuators capable of bending, twisting, and performing hybrid motions.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Engineering, Manufacturing
Hugo Girard, Behrad Koohbor, Aurelien Doitrand, Robert Livingston
Summary: Fiber-matrix interface debonding is investigated using a hybrid experimental-computational approach. The transient strain evolutions at the fiber-matrix interface are characterized to study the debonding initiation and propagation stages. A stress-based traction-separation model is identified based on the local deformation data obtained experimentally. The systematic methodology presented herein provides a quantification of the mechanics and failure at the fiber-matrix interfaces in unidirectional composites under transverse loading conditions.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Engineering, Multidisciplinary
Kazi Zahir Uddin, Ibnaj Anamika Anni, George Youssef, Behrad Koohbor
Summary: This study presents the design and development of (near) zero Poisson's ratio structures with considerable load-bearing capacities through an experimentally driven approach. These structures have excellent shape control capabilities in large deformation applications, and their load-bearing and energy absorption capacities are comparable to those of uniform cell structures.
ENGINEERING RESEARCH EXPRESS
(2023)
Article
Engineering, Mechanical
Somer Nacy, Behrad Koohbor, George Youssef
Summary: Frequency analysis is essential for revealing spectral features in time domain data and gaining insights into the dynamics of structures and materials. This study demonstrates the applicability of frequency-domain analysis for low-velocity impact scenarios, reporting important attributes of dynamic loading and material properties. The results show that the impact characteristics agree with previous reports based on time domain analysis, while also revealing the frequency dependence of acceleration and strain rate on foam density and impact energy.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
