Article
Crystallography
Junming Yuan, Yue Qin, Hongzheng Peng, Tao Xia, Jiayao Liu, Wei Zhao, Hu Sun, Yan Liu
Summary: In this study, friction ignition experiments were performed on HMX-based cast PBX explosives, revealing a critical ignition loading pressure of 3.7 MPa. The ignition characteristics were judged using numerical simulations at macro and micro scales, with the results indicating that HMX crystals can ignite at a temperature of 619 K. The main cause of friction ignition in HMX-based cast PBX is the friction hot spot generated by microcracks, while external friction heat has minimal effect on ignition.
Article
Materials Science, Multidisciplinary
Bing-Xin Liu, Qi-Xuan Du, Shi-Xiong Chen, Jiu-Hou Rui, Da-Bin Liu
Summary: This study investigated the mechanical behavior of high-quality RDX in pressed polymer bonded explosives (PBXs) with different formulations, focusing on compressive strength, shear strength, and tensile strength. Molecular dynamics simulation, scanning electron microscope, and surface energy calculation were used to analyze the effects of smooth, hard particles. The results showed that H-RDX did not contribute positively to the pressed PBXs system, with the decrease in binding force between binders and crystals due to the difficulty in spreading coating agents on H-RDX crystals. The mechanical strengths of H-RDX-based pressed PBXs were weakened, with a reduction in loading capacity of up to 65%.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Mechanics
Laibin Zhang, Guowen Wang, Xiaoyao Xu, Shanyong Xuan, Xin Fan, Yan Kan, Xuefeng Yao
Summary: In this paper, a progressive damage analysis model of thermal-mechanical coupling dynamic response and damage evolution for composites under drilling thrust and friction force is established. The model considers elastic dynamics, heat conduction, and damage criterion. The study also proposes a low damage strategy for drilling composites using support metal, and a quantitative evaluation method for composite damage during the drilling process.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Mechanical
Yan Qiao, Mohamed Arabi, Wei Xu, Hongxia Zhang, Eihab M. Abdel-Rahman
Summary: In this work, intrinsic noise sources in electrostatic MEMS were investigated and quantified, with a focus on their impact on the mass sensitivity of bifurcation-based inertial sensors. Experiments were conducted to measure the power spectral densities of mechanical-thermal noise and electric-thermal noise, and a stochastic model of the sensor was presented. The model showed that thermal noise caused an uncertainty of 2 Hz in the bifurcation frequency, leading to stochastic switching between stable orbits.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Engineering, Manufacturing
Shuye Zhang, Mingjia Sun, Jianqun Yang, Xingji Li, Peng He, Kyung-Wook Paik
Summary: This article investigates the reliability analysis of 3D CSP microelectro mechanical system (MEMS) and IC under thermal cycle impact coupled multiphysics loads. The mechanical behavior of the device is analyzed using COMSOL Multiphysics finite element software under a -55°C to 125°C thermal cycling and 1500 G at 1 ms with half-sine pulse impact coupled load. The study includes the analysis of thermal stress on single solder joint, whole device, and the simulation of device reliability under different magnitudes and forms of mechanical shock. The aim is to identify failure modes of interconnect structures including solder joints and the whole device for future design and optimize the layout of interconnect structures based on the stress distribution and deformation of the overall device.
IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY
(2023)
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
Energy & Fuels
Maria Warren, James E. Bean, Mario J. Martinez, Alec Kucala, Hongkyu Yoon
Summary: Accurate modeling of subsurface flow and transport processes is crucial for various subsurface activities. This study introduces a fixed stress scheme into the Sandia Sierra Multiphysics toolkit and evaluates its numerical accuracy and efficiency through benchmark problems and realistic conditions. The results demonstrate that the fixed stress scheme achieves acceptable numerical accuracy and efficiency in most cases, but requires finer tolerance for low permeable materials.
GEOMECHANICS FOR ENERGY AND THE ENVIRONMENT
(2022)
Article
Engineering, Civil
Xiwen Wang, Weijia Wang, Yuan He, Shulei Zhang, Wei Huang, R. Iestyn Woolway, Kun Shi, Xiaofan Yang
Summary: In this study, an improved parameterization scheme of the WRF-Lake model was applied to Lake Qiandaohu to simulate the thermal structure and stratification of the lake. By determining key parameters such as initial lake water temperature profiles, light extinction coefficients, eddy diffusion coefficients, and surface roughness lengths, the modified model performed better in simulating lake surface water temperature and thermal stratification. This study provides guidance for simulating the thermal structure of deep lakes and enhances our understanding of lake thermal stratification.
JOURNAL OF HYDROLOGY
(2023)
Article
Thermodynamics
Jing An, Ronghui Ju, Jianyou Zeng, Yiming Luo, Hao Luo, Haixia Ma
Summary: This study investigated the effect of thermoplastic polyurethane (TPU) and ethylene-vinyl acetate copolymer (EVA) on the pyrolysis and safety performance of polymer-bonded explosives (PBX) containing energetic materials (EMs). The results showed that TPU increased the activation energy of the EMs and inhibited the pyrolysis process, while EVA improved the thermal stability and ignition performance.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Green & Sustainable Science & Technology
Guofeng Song, Xianzhi Song, Fuqiang Xu, Gensheng Li, Gaosheng Wang, Jiayan Ji, Yu Shi
Summary: This study investigates the impact of chemical reactions on the operation of an enhanced geothermal system. The research findings highlight the significance of injection concentration (cin) as an efficient way to adjust geothermal production, while injection temperature (Tin) has little influence on chemical reactions.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Mechanical
Yangfan Li, Yingjie Zhang, Yanqing Zhao, Xiaojun Shi
Summary: This paper proposes a thermal-mechanical coupling calculation method for the deformation error of a motorized spindle. By calculating thermal load and force load, and analyzing their effects on the spindle, the deformation can be analyzed. The method is verified through finite element simulation and experiment.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Aerospace
Jiwei Tang, Weicheng Xie, Xiaoliang Wang, Cheng Chen
Summary: This study establishes a mechanical properties calculation model for near-space airship envelope materials, taking into account the effects of stress ratios, stress magnitudes, and temperatures. By using various simulation and analysis techniques, the fluid-structure-thermal coupling model of airship envelopes is developed, allowing for a more accurate prediction of stress-strain distribution and deformation characteristics.
Article
Engineering, Environmental
Jiamin Wang, Peng Zhang, Mohua Bu, Zhaolong Luan, Shouguang Wang
Summary: In this study, a numerical model was established to investigate the effect of high temperature on the mechanical performance of granite. The results showed that granite mainly suffered heat damage in the form of tensile cracks. With the increase in temperature, the degree of fracture in granite increased, exhibiting a post-peak decrease in brittleness and an increase in ductility. When the heating temperature exceeded 450°C, thermal damage began to dominate the failure mode of granite.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Thermodynamics
Xinyu Liu, Jianping Yang, Chunhe Yang, Zheyuan Zhang, Weizhong Chen
Summary: This study explores the use of ultra-high performance concrete (UHPC) and high-temperature resistant polyethylene for the support and tightness of underground caverns in compressed air energy storage (CAES). Through laboratory experiments and numerical modeling, the fatigue behavior of UHPC and the stability and heat transfer characteristics of CAES were investigated. The study provides insights for the future design of CAES.
Article
Chemistry, Physical
Pengsong Nie, Shaohua Jin, Xinyu Kou, Lixiaosong Du, Lijie Li, Kun Chen, Yu Chen, Junfeng Wang
Summary: This study investigates the effect of NTO content on the properties of HMX-based cast-PBX through experiments and simulations. The results demonstrate that the addition of NTO reduces the mechanical sensitivity of cast-PBX but decreases its energy level. The mechanical and thermal properties of cast-PBX show an increasing trend followed by a decreasing trend with the increase of NTO content. Moreover, the thermal safety performance of cast-PBX is greatly improved with the increase of NTO content.
Article
Engineering, Mechanical
Kun Yang, Yanqing Wu, Yi Wu, Fenglei Huang, Tao Chong, Zhaohui Zhang, Xianxu Zheng
Summary: A unified thermomechanical consistent model is developed to study the effects of multiple mechanisms on the thermomechanical properties of RDX crystals under high-pressure ramploading, showing good agreement with experimental data and revealing a four-wave structure behind the pressure wave profiles.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Chemistry, Physical
Yanlei Shang, Hongbo Ning, Jinchun Shi, Yi Wu, Sheng-Nian Luo
Summary: The rate constants of H-abstraction reactions from dimethylamine by triplets O and O-2 were theoretically determined using the CVT method. The M08-HX/ma-TZVP method was identified as the best by comparing the results with a gold-standard method. The calculations showed that OH and HO2 were mainly produced through direct abstraction from the C-H bond, and the multistructural torsional anharmonicity and tunneling effects played important roles.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Engineering, Multidisciplinary
Hong-zheng Duan, Yan-qing Wu, Kun Yang, Feng-lei Huang
Summary: A comprehensive understanding of drop-weight impacted responses for polymer-bonded explosives (PBXs) is crucial for evaluating their impact sensitivity. By simulating the deformation, fracture, formation of local high-temperature regions, and ignition of drop-weight impacted pressed PBXs using a coupled mechanical-thermo-chemical model, integrated with micro-defects evolution, a novel evaluation method for impact sensitivity is established. The analysis of impact velocity reveals that the critical local ignition impact velocity is determined to be 4.0-4.5 m/s. The simulation results indicate that shear-crack friction heating is the dominant ignition mechanism.
DEFENCE TECHNOLOGY
(2023)
Article
Optics
Yi Wu, Zhen Li, Qianlong Wang, Guillaume Legros, Chaomin Li, Zhiwen Yan
Summary: An original U-net convolutional neural network is proposed for retrieving local soot temperature and volume fraction fields from line-of-sight measurements. The U-net model's prediction ability and robustness to noise are validated and quantitatively studied. Comparative analysis with other algorithms demonstrates the effectiveness and accuracy of the U-net approach.
Article
Materials Science, Characterization & Testing
Hongzheng Duan, Yanqing Wu, Kun Yang, Wubuliaisan Maimaitituersun, Ning Wang, Jian shuai Chen, Fenglei Huang
Summary: This study investigates the mechanical properties, ignition response, and temperature rise mechanism of a novel propellant. The results indicate that the mechanical properties of the propellant are greatly influenced by the strain rate, and the ignition response is accentuated at higher strain rates.
Article
Energy & Fuels
Junsen Yang, Yi Wu, Zhenpeng Zhang, Yanlei Shang, Lun Pan
Summary: This study investigates the laminar flame speeds of JP-10/air mixtures and ignition delay time of JP-10/O-2/Ar mixtures through experimental measurements and numerical simulations. The results show a temperature dependence of laminar flame speed and identify key reactions that determine the flame speed and ignition delay time.
FRONTIERS IN ENERGY RESEARCH
(2022)
Article
Thermodynamics
Yi Wu, Zixiang Zhang, Qianlong Wang, Ningfei Wang
Summary: Paraffin-based fuel is a promising alternative for hybrid rocket motor applications due to high regression rate. However, paraffin fuel alone has poor mechanical strength. This study evaluated the mechanical and combustion characteristics of different polymer materials and found that ABS is a better candidate. Polymer reinforced paraffin fuel grains were found to improve combustion efficiency.
COMBUSTION AND FLAME
(2022)
Article
Materials Science, Multidisciplinary
Kun Yang, Hongzheng Duan, Yanqing Wu, Xiao Hou, Fenglei Huang
Summary: Understanding the impact-induced deformation and ignition properties of high-ductility composite energetic material (CEM) is crucial for the safety design and usage of rockets and warheads. In this study, an experiment and a thermomechanical model are used to investigate the deformation and reaction responses of CEM samples. The results reveal that high shear deformation rate leads to localized viscous shear flow heating, resulting in high temperature rise and ignition.
MATERIALS & DESIGN
(2022)
Article
Thermodynamics
Yiyao Wang, Junjie Wen, Junsen Yang, Guanglong Zhang, Ningfei Wang, Yi Wu
Summary: The thermal safety of a solid rocket motor using CL-20/GAP propellant with a complex charge structure was evaluated. Experimental and numerical studies were conducted to investigate the propellant's morphology, thermal decomposition properties, and the factors influencing ignition location and time.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Mechanics
M. Wubuliaisan, Yanqing Wu, Xiao Hou, Xiangyang Liu, Yi Wu
Summary: This paper presents a multiscale nonlinear viscoelastic constitutive model for NEPE propellant with high elongation, taking into account viscoelasticity, strain rate, confining pressure, and softening effects. The damage due to interface debonding or failure is investigated by analyzing microstructural changes in an RVE. A physics-based normalized debonding ratio is introduced and modeled using a cohesive zone model to capture the evolution of interface debonding. The model is implemented in ABAQUS for numerical analysis and shows good agreement with experimental results, considering the effects of strain rate, relaxation, creep, and confining pressure on stress response.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Chemistry, Applied
Haijiao Xue, Yanqing Wu, Kun Yang
Summary: In order to predict the safety of polymer-bonded explosives (PBXs) under accidental drop impact loading, a physical model is developed to describe the hotspot formation and ignition responses. The model incorporates microcrack and microvoid-related damage followed by ignition, which is predicted based on an innovative defect-related ignition criterion. The results show that microcrack hotspots and microvoid hotspots play critical roles under different impact velocities, and a defect-related criterion model is established for determining the threshold velocity for ignition occurrence.
JOURNAL OF ENERGETIC MATERIALS
(2023)
Article
Materials Science, Composites
Junjie Wen, Yi Wu, Xiao Hou, Mi Yan, Yachao Xiao
Summary: This study investigated the mechanical behavior and porosity of a T700/epoxy composite material under high temperature conditions. The results showed that the mechanical performance of the composite generally decreased with increasing temperature. Additionally, the porosity fraction of the tested samples under high temperature conditions was generally higher than that under lower temperature conditions.
JOURNAL OF REINFORCED PLASTICS AND COMPOSITES
(2023)
Article
Materials Science, Characterization & Testing
Hongzheng Duan, Yanqing Wu, Kun Yang, Xiao Hou, Wubuliaisan Maimaitituersun, Fenglei Huang
Summary: An experimental and numerical study was conducted to investigate the effects of strain rates on the mechanical responses and ignition mechanism of NEPE-based propellants. The results showed that the mechanical and ignition responses of the propellants are heavily dependent on strain rates. Viscous shear flow was found to be important for ignition, and the propellant exhibited a remarkable rate-dependence and viscous effect.
