Article
Chemistry, Physical
Hepeng Zhang, Zhongyi Cai, Jiaxuan Chi, Rujian Sun, Zhigang Che, Hongqiang Zhang, Wei Guo
Summary: This study investigated the fatigue crack growth behavior in residual stress fields induced by laser shock peening (LSP) on Ti6Al4V titanium alloy and found that LSP significantly extended the fatigue life. The significant crack retardation observed at high compressive stress levels was attributed to the reduction of local stress. The superposition principle combined with the weight function method was used to predict the fatigue crack growth rate in residual stress fields.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Zhongwei Xu, An Liu, Xishu Wang
Summary: This study investigates the performance differences between rolled and selective laser melted (SLM) Ti6Al4V alloys commonly used for orthopedic implants. The results show that the fatigue performance of SLM Ti6Al4V alloy is influenced by the building direction, with certain directions exhibiting excellent crack propagation resistance. Based on these findings, it can be expected that SLM components in different building directions will have varying fatigue performances.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Coatings & Films
Hepeng Zhang, Zhongyi Cai, Wei Guo, Hongqiang Zhang, Jianfeng Yan, Guangzhi He, Yongxin Zhang, Rujian Sun, Zhigang Che
Summary: This paper investigates the effects of laser shock peening on the fatigue resistance of aircraft parts. The results show that the introduction of compressive residual stresses prolongs the fatigue life significantly.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Engineering, Mechanical
Xiankai Meng, Xumin Leng, Chong Shan, Liucheng Zhou, Jianzhong Zhou, Shu Huang, Jinzhong Lu
Summary: In this study, ultrasonic-assisted laser shock peening (ULP) was proposed to improve the fatigue resistance of 2024-T351 aluminum alloys by combining ultrasonic shock peening (UP) and laser shock peening (LP) techniques to enhance the microstructure and mechanical properties. The microstructure, residual stress, microhardness, and vibration fatigue life of four different specimen types were tested and analyzed. The results showed that ULP significantly increased the dislocation density and refined the grains, leading to higher compressive residual stress and microhardness, which inhibited crack initiation and propagation, and thus greatly increased the vibration fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Han Cheng, Yongxiang Hu
Summary: The study investigates the generation and effect of crack face closure under laser shock, aiming to understand the reason for the high-level crack closure induced by laser peening on initial fatigue cracks. It is found that crack face closure results in a firm compression on the crack face, causing significant elongation in the crack wake during the crack opening process to prevent crack face separation under high-level external load. The contribution of crack face closure to crack retardation is comparable to laser peening-induced residual stress.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
D. C. van Aswegen, C. Polese
Summary: This paper focuses on the application of Laser Shock Peening (LSP) process to retard fatigue cracks in thin metallic airframe structural panels by creating compressive residual stress fields. Experimental results show that the best configuration, a 15 mm wide LSP region with a 15 mm offset from the crack tip, yielded a fatigue life of more than 6 times the baseline value.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Zhongwei Xu, An Liu, Xishu Wang, Bin Liu, Minghai Guo
Summary: The study provides a lot of high cycle fatigue data of SLM Ti6Al4V alloy, a new fatigue limit prediction model is applied when there are internal defects in the samples, and the fatigue crack propagation behavior and deformation mechanisms are discussed.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Piao Li, Luca Susmel, Mingze Ma
Summary: The study investigates the impact of Laser shock peening (LSP) on the fatigue life of notched metallic specimens. LSP is applied to notched specimens made of two aluminum alloys and fatigue tests are conducted. The stress field at the notch is measured using X-ray diffractometer and simulated using numerical methods. The highest compressive stress is found below the surface near the notch. A life prediction method is proposed by introducing the effective stress after LSP into the Theory of Critical Distances (TCD). The predicted results show good agreement with the experimental results.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Zehui Jiao, Xueren Wu, Huichen Yu, Ruida Xu, Lingliang Wu
Summary: Selective laser melting (SLM) has great potential in the aviation industry. This study investigated the fatigue performance of SLM Ti6Al4V alloy and analyzed the relationship between fatigue performance and pore characteristics. The results showed that subsurface pore was the main source of crack initiation for fatigue failure. By analyzing the pore characteristics in the crack source zone, it was found that anisotropy and dispersion of fatigue performance were closely related to the shape, size, location, and density of the pores. The fatigue life of the alloy was reasonably predicted using fracture mechanics method based on small-crack theory.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Chemistry, Physical
Niroj Maharjan, Thivyaa Ramesh, Zichen Wang
Summary: Industrial laser shock peening (LSP) is gradually moving away from using protective overlay as it is inefficient for production. However, peening of titanium alloys still requires protective coating. In this study, uncoated LSP of Ti6Al4V alloy was investigated and found to generate a thin oxide layer and a brittle alpha layer on the surface. Even though similar compressive residual stress was achieved as coated LSP, the fatigue performance did not improve due to microcracks in the alpha layer. Abrasive grinding to remove the alpha layer significantly increased fatigue life.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Mechanical
Xiaotai Feng, Xinlei Pan, Weifeng He, Ping Liu, Zhibin An, Liucheng Zhou
Summary: The study successfully applied warm laser shock peening (WLSP) technology as a post weld treatment to significantly increase the resistance of welded components to vibration failure. The high cycle vibration fatigue limit was improved by 42.3% through the introduction of high amplitude compressive residual stress, high stability of compressive residual stress, and surface nanostructure induced by WLSP.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Santiago Aguado-Montero, Carlos Navarro, Jesus Vazquez, Fernando Lasagni, Sebastian Slawik, Jaime Dominguez
Summary: Additive manufacturing (AM) of metallic parts is a new manufacturing procedure that has been applied in various industries. However, AM parts often have internal defects and surface roughness, resulting in lower fatigue strength compared to materials produced by traditional processes. This study investigated different surface treatments, including shot peening, laser peening, and shot peening plus chemical assisted surface enhancement, to improve the fatigue strength of AM parts. The results showed that laser peening produced the best results, followed by shot peening plus CASE and shot peening.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Optics
Seongguk Bae, Youngdae Kim, Jinesung Jung, Keesam Shin, Chang-Min Suh, Sungho Jeong
Summary: The effectiveness of laser shock peening was examined for Inconel 738 low-carbon material, showing significant improvement in surface hardness and compressive residual stress, enhancing the fatigue strength at low temperatures. However, the effectiveness of laser shock peening diminished at elevated temperatures.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Engineering, Mechanical
Zhao Wang, Wanting Zhou, Kaiyu Luo, Haifei Lu, Jinzhong Lu
Summary: The role of laser shock peening (LSP) on the thermomechanical fatigue properties of Ti6Al4V titanium alloy was studied. The effects of LSP with different coverage layers on the microstructural evolution, residual stresses distribution, and thermomechanical fatigue lives were analyzed. Results showed significant improvement in thermomechanical fatigue lives and changes in crack initiation locations and fracture surface features. LSP-induced plastic deformation, residual stresses, and grain refinement were identified as key factors contributing to the improved thermomechanical fatigue properties.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Yating Zhang, Kun Zhang, Zheng Hu, Tianyu Chen, Luca Susmel, Bingchen Wei
Summary: The synergetic effect of shot peening and laser shot peening on the fatigue behavior of a medium carbon steel was studied. The fatigue performance of the SP + LSP specimen was found to be improved only at lower stress levels, which is consistent with the observed short crack propagation behavior near the threshold region. The heterogeneous structures of ultra-fine grains, dislocation tangles, and high-angle grain boundaries were responsible for effectively retarding the short crack propagation.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Jinghui Wu, Ji Wang, Longtao Xie, Sergei Zhgoon, Rongxing Wu, Aibing Zhang, Tingfeng Ma, Jianke Du
Summary: The Rayleigh-Ritz method is commonly used for analyzing free vibrations of elastic solids and structures. In this study, the Cartesian coordinate system is utilized for a simplified formulation and efficient evaluation of the vibrations of elastic ellipsoids. The procedure and formulation are validated by calculating the vibrations with geometric parameters and comparing them with known results and analysis from this study.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Thermodynamics
Aibing Zhang, Dandan Pang, Baolin Wang, Ji Wang
Summary: This paper develops a thermodynamic model based on dual-phase-lag bioheat transfer for the system of skin and wearable thermoelectric generators (WTEGs). The analytical solutions for temperature distribution and energy conversion performance of WTEGs are obtained. Several important conclusions are drawn, such as the consideration of blood perfusion heat convection and the neglect of contact thermal resistance between the skin and WTEG interface.
Article
Thermodynamics
Aibing Zhang, Guangyong Li, Baolin Wang, Ji Wang, Jianke Du
Summary: This paper develops a biothermomechanical model of skin for hyperthermia treatment of cancer based on the non-Fourier bioheat transfer theory. The model considers skin as a three-layer tissue with homogeneous and linear thermoelasticity. Analytical solutions of temperature profile and stress distribution are derived considering different factors. Numerical results show the significant influence of blood perfusion and sweating on temperature, thermal damage, and stress. The findings provide insights into skin biothermomechanics and can guide the design of biomedical devices for hyperthermia treatment.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Multidisciplinary
Chencheng Lian, Ji Wang, Baochen Meng, Lihong Wang
Summary: This paper successfully solves the nonlinear differential equation of deflection of an elastic beam using the Galerkin method. It demonstrates the high consistency between the third-order approximate solution and the exact solution of the elliptic function. The effectiveness and advantages of the Galerkin method in solving nonlinear differential equations are further demonstrated.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Mechanical
Ji Lin, Jin Qian, Yu Xie, Ji Wang, Rui Xiao
Summary: In this study, a micromechanical mean-field shear transformation zone (STZ) model is developed to systematically describe the stress responses of amorphous polymers. The model captures the behaviors of amorphous polymers in various loading conditions and successfully reproduces the Bauschinger effect. The deformation-induced material polarization, in the form of an anisotropic distribution of STZs, is identified as the governing mechanism of the Bauschinger effect.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Yumei Chen, Xiang Fang, Ji Wang, Matteo Filippi, Erasmo Carrera
Summary: By using a microstructure with an antisymmetric dual helix, we designed a metamaterial plate with wide band gaps for phononic crystals. The band structure and displacement transmission curves of the metamaterial plates were calculated and compared with and without considering the mass in the center of the dual helix. The results show excellent consistency in the band gaps, and the effects of various parameters on the band gaps were examined for further evaluation of potential applications.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Dongdong Guo, Haozhe Jiang, Lili Yuan, Tingfeng Ma, Jianke Du, Ji Wang
Summary: A metamaterial beam with carbon fiber-reinforced polymer (CFRP) is proposed to effectively reduce vibration. The dispersion curves are calculated using the transfer matrix method (TM), the frequency response is investigated using the spectral element method (SEM), and the displacement fields at different representative frequencies are displayed using the finite element method (FEM). Numerical analysis considers the effects of geometry, material parameters, and CFRP's cross-ply angle on the band gap, and three types of beams are discussed and compared. The results show that the cross-ply angle and length of CFRP significantly influence the band gaps, and the frequency and width of the band gaps vary when the CFRP layers are asymmetric. Experimental results agree well with numerical results in the low-frequency range for a CFRP beam with ten periods. These findings provide useful reference for the design optimization of metamaterial beams with wide band gaps, lightweight properties, and high strength.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Engineering, Mechanical
Chencheng Lian, Baochen Meng, Huimin Jing, Rongxing Wu, Ji Lin, Ji Wang
Summary: This study analyzed the higher-order nonlinear vibrations and mode couplings of beams using the extended Galerkin method for a better understanding of dynamic properties. Numerical solutions of frequencies and mode shapes were obtained for a cantilever beam by approximating and solving the vibration equation under large deformation. The results demonstrated that the approximate solutions were accurate compared to the exact solutions for small amplitudes.
JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES
(2023)
Article
Physics, Applied
Jiachao Xu, Yuanzhen Zheng, Tingfeng Ma, Hui Chen, Bowei Wu, Ji Wang, Shuanghuizhi Li, Iren Kuznetsova, Ilya Nedospasov, Jianke Du, Hao Shi, Dudu Chen, Fei Sun
Summary: In this study, the topological valley Hall edge states of elastic waves in phononic crystals were achieved by utilizing material differences. A phononic crystal structure with lantern rings was proposed, and it was found that differences in Young's modulus or density of the lantern-ring materials can cause the destruction of the spatial inversion symmetry, leading to the emergence of topological edge states. By reconfiguring the waveguide path and changing the operating frequency through modifying the lantern-ring materials, the limitations of traditional methods based on structural parameter changes were overcome, providing a promising approach for elastic wave manipulation and communication.
PHYSICAL REVIEW APPLIED
(2023)
Review
Infectious Diseases
Bao Sun, Yingshuang Tang, Dan Chen, Yanning Bai, Yuanyuan Zhang, Suning Chen, Yi Qiao, Jingwen Wang
Summary: Biliary cryptococcal infection is rare and difficult to diagnose preoperatively. This case report and literature review collected a total of 12 reports of biliary cryptococcal infection from 1985 to 2021. Clinical manifestations were mainly jaundice, with bile duct dilatation and stenosis observed in vitro. Treatment with antifungal drugs resulted in symptom improvement or recovery in 66.67% of the cases. Early and accurate diagnosis is crucial for improving the cure rate of biliary cryptococcosis infected patients.
INFECTION AND DRUG RESISTANCE
(2023)
Article
Thermodynamics
Dandan Pang, Aibing Zhang, Yage Guo, Junfeng Wu
Summary: This paper proposes a novel configuration for wearable thermoelectric generators and develops an analytical model based on human skin. The study finds that neglecting the metabolic heat generation underestimates the maximum power density of the generator, while increasing the contact pressure at the skin/W-TEG interface improves the performance.
Article
Materials Science, Multidisciplinary
Yangyang Zhang, Qi Lai, He Zhang, Yingwu Yang, Ji Wang, Chaofeng Lu
Summary: In this study, an electromechanical model is established to consider the wheel-path distribution under actual traffic conditions. The optimal lateral embedded locations for PEH units should be adjusted according to the prescribed traffic speed of the roads, and these mathematical results serve as guidelines for selecting the optimal lateral embedded locations for PEH units.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
J. H. Wu, J. Wang, E. Carrera, R. Augello
Summary: This work analyzes the wave propagation of Rayleigh type through a periodic elastic element covered with a T-plate. Viscous-spring artificial boundaries are used to satisfy the boundary conditions of the periodic structure. The Carrera Unified Formulation (CUF) is used to consistently express the various kinematics of the structure and obtain the wave propagation within the model. The numerical evaluation and comparison with analytical methods and COMSOL show that the results of this study are reliable and the developed model provides accurate analysis of T-plate periodic elastic structures.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Acoustics
Yurun Chen, Yan Guo, Rongxing Wu, Ji Wang, Huimin Jing, Ji Lin, Yahui Tian, Haifeng Zhang
Summary: The fast reduction in size of film bulk acoustic wave resonators results in enhanced electric fields and potential large deformations in operating devices. Therefore, the nonlinear behavior and accompanying properties of the resonator need to be considered in development and optimization for improved performance. A nonlinear formulation is presented for multilayered film bulk acoustic resonators, allowing analysis of vibration frequencies and mode shapes with consideration of larger mechanical deformations. Extensive research efforts have been made analytically and experimentally to understand the nonlinear behavior and properties, catering to the demands of communication and network technologies.
Article
Mechanics
Xiaolong Liu, Kelian Luo, Pengcheng Gao, Tao Cong, Xi Wang, Wenjing Wang
Summary: This paper investigates the formation mechanisms of the zig-zag crack region on the shattered rim of railway wheels. The zig-zag crack region, identified as a typical region for crack propagation in rolling contact fatigue behavior, was observed using scanning electron microscopy and transmission electron microscopy. The formation of the zig-zag morphology is attributed to the periodic deflection of the propagation path relative to the initial propagation plane, caused by the limited plastic deformation zone at the crack tip. Grain refinement and secondary cracks in the zig-zag crack region are a result of the large compressive and shear stresses induced by rolling contact loading.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Anastasia Iziumova, Aleksei Vshivkov, Ivan Panteleev, Virginia Mubassarova, Oleg Plekhov, Denis Davydov
Summary: The aim of this study was to investigate the correlation between structural, acoustic emission, and thermal characteristics of fatigue crack growth in titanium alloys. Cluster analysis of the acoustic emission signals revealed two different types of signals observed during the fatigue crack development. It was experimentally demonstrated that the stored energy tends to reach an asymptotic value at the final stage of fatigue crack growth and this is correlated with the twinning process intensification in titanium alloy Ti Grade 2. A correlation was assumed between the stages of change in heat flux, the cumulative energy of the first cluster of acoustic emission signals, and the crack length.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
M. Vieira de Carvalho, I. A. Rodrigues Lopes, F. M. Andrade Pires
Summary: This study investigates the numerical challenges of fracture mechanics models within implicit quasi-static frameworks and proposes an instability criterion. The ratio of cohesive to internal power is identified as a crucial factor. Two strategies for handling fracture problems with instabilities are discussed and a comparative assessment is performed. The study also examines more complex material responses, including transformation-induced plasticity effects.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Thomas Duminy, Aurelien Doitrand, Sylvain Meille
Summary: This study conducted in situ wedge splitting tests on millimeter-size PMMA samples and proposed a method to determine the material tensile strength and critical energy release rate using digital image correlation and a full finite element implementation of the coupled criterion.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Xin Chang, Xingyi Wang, Chunhe Yang, Yintong Guo, Yanghui Wan
Summary: The influence of cyclic thermal shock and high-temperature acid etching on the Mode I fracture of shale was investigated in this study. It was found that cyclic thermal shock severely degrades the strength and fracture toughness of shale, while high-temperature acid etching treatment improves the fracture toughness. These findings are valuable for optimizing process parameters to reduce initiation pressure in deep shale formations.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Liaojun Yao, Mingyue Chuai, Zhangming Lyu, Xiangming Chen, Licheng Guo, R. C. Alderliesten
Summary: Methods based on fracture mechanics have been widely used in fatigue delamination growth (FDG) characterization of composite laminates. This study proposes appropriate similitude parameters to represent FDG behavior with different R-ratios.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Zesheng Zang, Zhonghui Li, Yue Niu, Shan Yin
Summary: This study conducted experiments and recorded signals to investigate the fracture behavior and damage evolution characteristics of coal samples. The results showed that as loading proceeds, the stress, electric potential (EP), and acoustic emission (AE) values increase, and EP and AE signals are excited when stress drops. The fracture behavior of coal samples is altered by flaw inclination, and the destruction mode becomes increasingly complicated. The damage evolution characteristics of coal samples can be evaluated and analyzed by defining the coefficient of variation (CV value) of EP and the b value of AE.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Clotilde Berdin, Nathalie Prud'homme
Summary: In this study, zirconia layers with different fractions of tetragonal phase and thicknesses were tested for multi-cracking behavior. Cracks perpendicular to the tensile direction were observed, showing a blunting effect into the substrate. The ratio of crack spacing at saturation to layer thickness decreased as the layer thickness increased. Unit cell modeling was used to establish a relationship between crack spacing and layer strength, which fell within the bounds of Hu and Evans model and was found to be insensitive to the tetragonal zirconia fraction.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Huadong Zhang, Weichen Kong, Y. H. Liu, Yuh J. Chao
Summary: Williams' series expansion crack tip solution in linear elasticity is modified to include a uniform crack face pressure. Practical methods to calculate T-stress from near crack tip stresses are outlined. The analytical results are consistent with numerical results.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Jiahao Kong, Haoyue Han, Tao Wang, Guangyan Huang, Zhuo Zhuang
Summary: This paper introduces a phase-field model for polymer foam materials by combining the phase-field method with the crushable foam model. The model is calibrated using experimental data and successfully simulates the fracture processes of polyurethane under different loading conditions. The study is important for the engineering applications of polymer foam materials.
ENGINEERING FRACTURE MECHANICS
(2024)
