Article
Engineering, Electrical & Electronic
Zehua Wu, Huidong Tian, Sijia Zhu, He Li, Qingyu Wang, Zongliang Xie, Peng Liu, Zongren Peng
Summary: This study investigated the initiation mechanisms of crack-induced electrical tree and revealed the reasons for erosion near the crack border. It was found that erosion and tree initiation typically occur at the border of the crack under a relatively low electric field strength, while the area near the electrode remains relatively undamaged. The breaking of epoxy molecular chains leads to coarsening of the crack surface and the formation of deep channels on a micro-level, which are precursors to electrical tree inception.
Article
Materials Science, Multidisciplinary
Gongyuan Liu, Yichun Tang, Khalid Hattar, Yuzhou Wang, William Windes, Aman Haque, Jing Du
Summary: This study aims to establish an experimental method to investigate pre-existing defects and 3-D crack growth inside nuclear graphite. Three-point bending tests were performed on specimens with and without micro-CT. The results highlight the capability of laboratory micro-CT-based experimental method for the visualization of multi-scale defect interactions, which remains to be a challenge in the characterization of nuclear graphite.
JOURNAL OF MATERIALS RESEARCH
(2023)
Article
Engineering, Mechanical
Masami Matsubara, Ryo Takara, Taichi Komatsu, Shogo Furuta, Khoo Pei Loon, Masakazu Kobayashi, Hitomu Mushiaki, Kentaro Uesugi, Shozo Kawamura, Daiki Tajiri
Summary: Observing the internal state during deformation is important for understanding the mechanical properties of polymeric materials like rubber. In this study, an experimental system was developed to simultaneously measure the dynamic mechanical properties and dynamic X-ray computed tomography (CT) of rubber materials. The results showed that the excitation frequency had minimal effect on the deformation amplitude in SBR material, while the excitation amplitude influenced the median value of local strain amplitudes. Comparing different base materials with distinct loss factors, no significant differences were observed in the histograms of local strain amplitudes, although the histograms varied based on formulation conditions.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Multidisciplinary
T. Nagoshi, Y. Harada, S. Nakasumi, N. Yamazaki, K. Hasegawa, K. Takagi, W. Peng, G. Fujii, M. Ohkubo
Summary: Cohesive failure in the epoxy adhesive layers of carbon-fiber-reinforced plastic (CFRP) joints is a perplexing issue. This study reveals that micrometer-scale defects may contribute to the occurrence of cohesive failure and proposes a new phenomenological model to explain this behavior. These findings are of significant importance for enhancing the reliability of CFRP components.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Materials Science, Ceramics
Guoqi Liu, Hongxia Li, Han Zheng, Fan Qian, Weikui Ma, Wengang Yang
Summary: This study investigated the formation mechanism of magnesia alumina spinel in Al2O3-C refractories with magnesia addition at different firing temperatures. Compared to traditional analogs, the mechanical properties of Al2O3-C refractories were comprehensively studied. It was found that the magnesia alumina spinel was in-situ formed at 1150 degrees C, leading to improvements in interfacial bond, load transferring capacity, and crack propagation resistance. The formation of the spinel phase also enhanced the sintering of the alumina matrix, resulting in significant enhancements in mechanical properties.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Ruicong Lv, Haichang Guo, Lei Kang, Akbar Bashir, Liucheng Ren, Hongyu Niu, Shulin Bai
Summary: With the development of the electronics industry, there is an increasing demand for packaging materials with high thermal conductivity and low electrical conductivity. Graphene, with its high thermal conductivity and electrical conductivity, has the potential to enhance the thermal conductivity of epoxy composites. However, the high electrical conductivity of graphene limits its application in cases where electrical insulation is required. A solution to this challenge is to coat graphene sheets with an in-situ grown Al2O3 layer, resulting in epoxy-based composites with both high thermal conductivity and low electrical conductivity.
Article
Engineering, Mechanical
Vhaisraj Rajashekar, Mahendra Gattu
Summary: We investigate the effect of adding nano-alumina on the mechanical strength of epoxy resins. The results show that as the weight fraction of nano-alumina increases, the fracture toughness and fracture process zone size of the epoxy resin also increase. This indicates that nano-alumina has a toughening effect on epoxy resins.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Alan Xu, Michael Saleh, Dhriti Bhattacharyya
Summary: The effects of hole shape and orientation on the mechanical properties of micro-scale 2D honeycomb structures were investigated. The results showed significant changes in strength and ductility depending on the orientation and shape of the holes. Samples with 30 degrees oriented hexagonal holes had the lowest strength and highest ductility, while samples with circular holes showed the greatest yield and tensile strength. Samples with 0 degrees orientated hexagonal holes had higher strength and lower ductility compared to the 30 degrees orientated ones.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Yi Zhao, Liying Ju, Xiaopei Guo, Tao Li, Min Tan, Han Guo, Shaopeng Gu
Summary: The three-dimensional morphology of alumina clusters in steel samples was observed using X-ray Micro-CT technology and Avizo software, revealing their actual morphology. A series of parameters were defined to characterize the morphological characteristics of alumina clusters, and fractal theory was introduced for quantitative description. This study provides an effective method for quantitative description of impurity morphology and spatial distribution, and it serves as an important reference for effective control of alumina inclusions.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Physical
M. M. Simunin, A. S. Voronin, Yu. V. Fadeev, S. S. Dobrosmyslov, A. A. Kuular, T. A. Shalygina, K. A. Shabanova, D. Yu. Chirkov, S. Yu. Voronina, S. V. Khartov
Summary: This paper investigates the effects of adding alumina nanofibers on the mechanical properties of epoxy resin. It is found that the addition of alumina nanofibers can increase the flexural strength of the resin, but exceeding a certain threshold leads to a decrease in strength. Furthermore, adding nanofibers lowers the resin's glass transition temperature, indicating a decrease in molecular weight.
Article
Chemistry, Physical
Fei Teng, Ching-Heng Shiau, Cheng Sun, Robert C. O'Brien, Michael D. McMurtrey
Summary: This study investigates the microstructures and mechanical properties of additively manufactured AISI 316L stainless steel. Both single-phase and dual-phase substructures were observed, with the dual-phase substructures exhibiting lower yield strength and higher Young's modulus compared to the single-phase substructures. The research also suggests that uneven heat treatment in the printing process could lead to elemental segregation, thus negatively affecting the mechanical properties.
Article
Materials Science, Composites
Mikhail V. Burkov, Alexander V. Eremin
Summary: This study investigated the effects of adding milled carbon fibers and single-wall carbon nanotubes on the mechanical and physical properties of carbon-fiber-reinforced polymers. It was found that single-wall carbon nanotubes significantly improved static strength and fatigue performance, while milled carbon fibers enhanced properties under static loading but negatively impacted fatigue properties.
POLYMER COMPOSITES
(2021)
Article
Mathematics, Interdisciplinary Applications
Dongmei Huang, Shuyu Qiao, Xikun Chang, Xinzhao Wang, Huanhuan Lu, Xin Pan
Summary: The influence of holes and crack spacing on the strength and failure mode of rock samples was studied. The macroscopic mechanical behavior of rock-like samples was summarized through compression testing. Numerical models were calibrated based on experimental results and used to simulate the loading process. The study analyzed the micro-failure mechanism from the perspective of mechanical properties, particle displacement, and failure mode.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Amr Osman, Abdelmoty Elhakeem, Saleh Kaytbay, Abdalla Ahmed
Summary: By dispersing reduced graphene oxide (RGO) and alumina into the epoxy matrix at different hybrid ratios, the synergy of RGO and alumina at 6:4 was found to enhance thermal conductivity by 23.4%, retain insulation properties, increase tensile strength, and improve storage modulus. The settling of alumina nanoparticles on the graphene surface inhibits electron transfer and eliminates graphene agglomerations, making it an important study for designing optimal multi-functional polymeric packaging materials.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Xueyu Zhao, Zhiyang Deng, Zhiheng Yu, Tingyi Li, Xiaochun Song
Summary: Due to special geometric features and complex working environments, internal defects of small-diameter thick-walled steel pipes are prone to expansion and difficult to detect. This paper proposes a magnetic permeability perturbation testing (MPPT) method to assess internal axial cracks of small-diameter thick-walled steel pipes. The mechanism of the MPPT method and its corresponding probe and magnetizer are introduced, and its feasibility is verified through simulations and experiments. The experiments using different sizes of small-diameter thick-walled pipes demonstrate that this method performs well in detecting internal axial cracks. Diameter and wall thickness greatly affect the MPPT signal, with greater wall thickness or smaller diameter resulting in weaker signals. This method is not affected by the lift-off effect or limited by the skin effect, making it valuable for evaluating thick-walled steel pipes.
APPLIED SCIENCES-BASEL
(2023)
Article
Biophysics
Dave Schmitthenner, Carolyn Sweeny, Jing Du, Anne E. Martin
JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME
(2020)
Article
Engineering, Multidisciplinary
Michael Hillman, Kuan-Chung Lin
Summary: Enforcement of essential boundary conditions in many Galerkin meshfree methods is non-trivial due to the disconnect between field variables and coefficients at nodal locations. This inconsistency leads to loss of Galerkin orthogonality and the best approximation property. Two new weak forms are introduced to relax the requirements on test and trial functions, allowing for optimal accuracy and convergence rates.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Mathematics, Interdisciplinary Applications
Jonghyuk Baek, Jiun-Shyan Chen, Guohua Zhou, Kevin P. Arnett, Michael C. Hillman, Gilbert Hegemier, Scott Hardesty
Summary: In this work, the particle-based Godunov shock algorithm and semi-Lagrangian reproducing kernel particle method (SL-RKPM) were successfully introduced to accurately simulate the key shock physics in explosive welding process. In addition, an improved algorithm for kernel stability and the adoption of quasi-conforming nodal integration method effectively avoided tedious operations in extreme deformations.
COMPUTATIONAL MECHANICS
(2021)
Editorial Material
Materials Science, Multidisciplinary
Jing Du, Dinesh Katti, Hendrik Heinz
Article
Engineering, Biomedical
Kangning Su, Yuxiao Zhou, Mehran Hossaini-Zadeh, Jing Du
Summary: In this study, finite element models based on micro-CT images were used to investigate bone-implant mechanics, showing higher strain concentration in the thinner buccal bone plates and the impact of implant distance from the buccal plate on mechanical stimuli in bone, which may affect bone remodeling and resorption processes.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Editorial Material
Materials Science, Multidisciplinary
Jing Du, Dinesh Katti, Hendrik Heinz
Article
Engineering, Multidisciplinary
Jiarui Wang, Guohua Zhou, Michael Hillman, Anna Madra, Yuri Bazilevs, Jing Du, Kangning Su
Summary: This work introduces immersed volumetric Nitsche methods to address the challenges of generating quality body-fitting meshes for complex composite microstructures. These methods enforce volumetric continuity and demonstrate consistency with the strong form of the composite problem, allowing for different levels of approximations. Experimental results show that the non-symmetric version of Nitsche's approach is the most robust in all settings.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Engineering, Biomedical
Yuxiao Zhou, Junlong Dang, Ye Chen, Song Guo Zheng, Jing Du
Summary: Rheumatoid arthritis is a systemic polyarticular arthritis that affects small joints and currently lack curable treatments. The study shows that human gingiva-derived mesenchymal stem cells have the potential to interfere with the progression of autoimmune arthritis, reducing bone erosion and improving bone function.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Editorial Material
Materials Science, Multidisciplinary
Jing Du, Dinesh Katti, Vinoy Thomas
Article
Chemistry, Multidisciplinary
Xinyu Tan, Ethan Gerhard, Yuqi Wang, Richard T. Tran, Hui Xu, Su Yan, Elias B. Rizk, April D. Armstrong, Yuxiao Zhou, Jing Du, Xiaochun Bai, Jian Yang
Summary: The burden of bone fractures necessitates effective biomaterial solutions. A class of citrate-based polymer/hydroxyapatite composites (BPLP-Ser/HA) with intrinsic fluorescence and osteopromotive properties were developed, which demonstrated biocompatibility, hydration-induced mechanical strengthening, tunable degradation rates, hemostatic sealing potential, adhesion to bone, antimicrobial effects, and in vivo bone regeneration equivalent to autograft.
Article
Materials Science, Multidisciplinary
Kangning Su, Chengyao Gao, Guoxian Qiu, Li Yuan, Jie Yang, Jing Du
Summary: By comparing the numerical simulation of mechanically adaptive bone remodeling with clinical images, a spatial distribution map of bone density was obtained. The results showed that biting forces and stimulation near tooth roots increased trabecular bone density, while bending and torsion moments on the mandible resulted in lower bone density near the center. These findings provide a new method to compare simulation results with experimental data and offer model parameters for predicting bone density distribution around dental implants.
Review
Biochemistry & Molecular Biology
Yuxiao Zhou, Jing Du
Summary: This review discusses the effects of bone remodeling activities on the structures and properties of bone, and introduces the application of Atomic Force Microscopy (AFM) technique in bone research. The AFM technique is used for surface morphology imaging, contact indentation testing, and other mechanical tests of bone. The review also covers the application of sub-resonance tapping mode in biological molecules, cells, and tissues.
PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Gongyuan Liu, Yichun Tang, Khalid Hattar, Yuzhou Wang, William Windes, Aman Haque, Jing Du
Summary: This study aims to establish an experimental method to investigate pre-existing defects and 3-D crack growth inside nuclear graphite. Three-point bending tests were performed on specimens with and without micro-CT. The results highlight the capability of laboratory micro-CT-based experimental method for the visualization of multi-scale defect interactions, which remains to be a challenge in the characterization of nuclear graphite.
JOURNAL OF MATERIALS RESEARCH
(2023)
