International Core Journal of Engineering
International Core Journal of Engineering is an international journal to promote all fields of Engineering, it considers original and timely contributions containing new results in mechanical engineering, electrical engineering, civil engineering, chemical engineering, etc. All articles published are rigorously and fast reviewed meeting the Journal Quality standards.
Application of Unmanned Aerial Vehicles in Emergency Medical Field
This paper focuses on the application of unmanned aerial vehicles (UAVs) in the emergency medical field. Endowed with characteristics such as easy operation, flexibility and rapidity, UAVs play a crucial role in emergency medical services. They enable emergency delivery to enhance response speed, as exemplified by their assistance in patient transfer during the heavy rain in Zhengzhou and the significant improvement in drug delivery efficiency in Suzhou. Additionally, UAVs optimize medical resources to support remote areas, as seen in their use for transporting vaccines during the epidemic. They also enhance safety and provide telemedicine support. The paper further analyzes the technical and management scheduling challenges faced by UAV applications, including limited battery life and system incompatibility, and proposes countermeasures such as improving battery life and optimizing communication. It points out that UAVs will become a core tool in emergency medical services in the future.
Unmanned Aerial Vehicle; Emergency Rescue; Low-Altitude Economy.
Copyright (c) 2025 International Core Journal of Engineering https://creativecommons.org/licenses/by-nc/4.0
Mechanical Behavior and Research Prospects of Curved Pipe Jacking
With the increasing emphasis on the sustainable development of underground space, the importance of trenchless pipe roofing jacking technology has become more prominent. In practical engineering, pipe jacking often needs to advance along a curved path due to geological conditions, environmental interferences, and other factors. Compared with the relatively mature technology of straight pipe jacking, curved pipe jacking demonstrates greater adaptability but also poses more severe challenges in terms of jacking force estimation, trajectory control, soil disturbance prediction, and the performance of pipe segments and joints. This paper systematically analyzes the differences between straight and curved pipe jacking, pointing out that the estimation of the jacking force for curved pipe jacking is a dynamic process influenced by multiple factors, which existing theoretical models struggle to accurately describe. The disturbance effect of curved jacking construction on the surrounding soil is more significant, with the research foundation for horizontal curved pipe jacking being particularly weak. Meanwhile, the mechanical performance of joints, such as flexural stiffness, is crucial for ensuring the success of curved jacking. Therefore, this paper proposes that future research should focus on three core directions: first, developing segmented or distributed theoretical models based on numerical simulations that can reflect the dynamic variation of jacking force; second, establishing accurate prediction models for soil disturbance and settlement specifically for curved pipe jacking, particularly for horizontal curves; third, developing joint design methods that balance mechanical performance, sealing, durability, and economic efficiency, while comparatively studying the mechanical behavior of joints in curved and straight pipe jacking. Relevant research holds significant theoretical and practical importance for enhancing the technical level of curved pipe jacking and ensuring engineering safety.
Curved Pipe Jacking; Soil Disturbance; Pipe Joints.
Research Flexural Test and Crack Development of PVA-steel Fiber Composite Reinforced Recycled Concrete Beams
Excessive crack width and numerous cracks in high-strength recycled concrete beams significantly impair their serviceability. To address this, steel fibers and polyvinyl alcohol (PVA) fibers-known for their excellent crack resistance-were incorporated into high-strength recycled concrete beams to effectively restrict crack development. Through flexural tests on six steel/PVA fiber-reinforced recycled concrete beams, one natural aggregate concrete beam, and one recycled concrete beam without fibers, the effects of PVA fiber volume ratio, steel fiber volume ratio, and PVA-steel hybrid fibers on the average crack width under serviceability limit state, maximum crack width under ultimate limit state, and the number of cracks during loading were investigated. The results demonstrate that the incorporation of hybrid steel and PVA fibers effectively inhibits cracking in recycled concrete beams, reducing the maximum crack width under ultimate load by 47.5%. The failure load of hybrid fiber-reinforced recycled concrete beams exceeded that of both single-fiber recycled beams and the natural concrete beam, while exhibiting crack resistance comparable to that of natural concrete.
Recycled Aggregate Concrete Beam; PVA Fiber; Steel Fiber; Maximum Crack Width; The Number of Cracks.
Research on the Weights of Subjective Evaluation Metrics of Automobile Squeak & Rattle based on Entropy Method
This study aims to objectively quantify the weights of subjective evaluation metrics for automobile squeak and rattle (S&R) using the entropy method. The paper first elaborates on the theoretical foundation and calculation steps of the entropy method, then integrates the core principles of the Analytic Hierarchy Process (AHP) to construct a comprehensive subjective evaluation framework. The test roads and operating conditions for subjective evaluation were clearly defined. In the evaluation experiment, three experienced engineers assessed five passenger vehicles on a proving ground using a 10-point scoring system. The collected rating data were processed using the entropy method to determine the weights of each metric, followed by the calculation of the overall subjective evaluation score for each vehicle. The results demonstrate that the entropy method, relying on objective data, effectively determines metric weights with high objectivity, providing a more scientific assessment approach for target setting in the early stages of vehicle development.
Squeak & Rattle; Subjective Evaluation; Entropy Method; Metric Weights.
Neutrino Tomography with Artificial Neutrino Beams: A Novel Approach to Probing Earth's Internal Structure and Density Profile
Understanding Earth's internal structure is critical for geophysical sciences, but traditional seismic tomography faces limitations such as the inability of S-waves to penetrate the liquid outer core and the difficulty in distinguishing minerals with similar seismic velocities. This study proposes a novel approach using neutrino tomography with artificial neutrino beams to address these challenges. Neutrinos, due to their weak interaction properties, can traverse the entire Earth, making them ideal probes for deep interior exploration. The methodology involves constructing a six-layer spherical Earth model (Continental Crust, Upper Mantle, Transition Zone, Lower Mantle, Outer Core, and Inner Core) based on the Preliminary Reference Earth Model (PREM). By simulating neutrino beams with fixed energy (10 GeV) propagating along six distinct trajectories through these layers, the absorption and survival probabilities of neutrinos are calculated using the Bouguer-Beer-Lambert Law and neutrino-nucleon interaction theory. A system of linear equations is derived to invert the Earth's density profile from the simulated survival data, validated through Monte Carlo simulations (1000 iterations with 10,000 neutrinos per path). Results show strong consistency between inverted densities and PREM, with a maximum relative error of 0.67% (Transition Zone) and a root-mean-square error (RMSE) of ~0.023 g/cm³. Notably, the inner core exhibits the smallest relative error (0.15%), highlighting neutrino tomography's unique advantage in penetrating high-density regions inaccessible to seismic S-waves. This study demonstrates the feasibility of neutrino tomography as a complementary tool to seismic methods, offering new insights into Earth's composition and dynamics with implications for geophysics, planetary science, and resource exploration.
Neutrino Tomography; Earth’s Internal Structure; Density Inversion; Neutrino-Nucleon Interaction; Preliminary Reference Earth Model.
Design and Performance Study of an Intelligent Glass System based on Multi-Modal Collaborative Regulation
This paper designs and proposes a triple-layer composite smart glass system integrating electrochromic, photochromic, and passive thermal insulation functionalities. To address spectral interference issues in conventional multilayer structures, this study employs ANSYS Lumerical and COMSOL Multiphysics for modeling and simulation, optimizing a tungsten oxide-ITO composite electrode structure and a hybrid naphthopyran/spiropyran photochromic system. Simulation results demonstrate that transmittance fluctuations can be controlled within 5%. For control strategies, a dual-mode light intensity sensing network and a hierarchical control model based on a Kalman filter algorithm were developed in the Simulink environment. Simulations verified that this strategy stabilizes indoor illuminance within ±5% of the set threshold. Furthermore, system performance was evaluated using EnergyPlus building energy consumption simulation software. Results indicate that in a standard building model, compared to traditional double-pane insulating glass, the system reduces summer air conditioning energy consumption by 42% and winter heating demand by 28%. Through multi-physics simulations and system modeling, this study provides an innovative solution and theoretical foundation for dynamic optical-thermal management in building envelopes.
Smart Glass; Multimodal Regulation; Optical-thermal Cooperative Control; Building Energy Efficiency; Multiphysics Simulation.
Research on Recognition and Estimation Algorithm for Real time Changes in the Center of Gravity of Human Sitting Quality
This article explores the interference estimation problem of human body mass changes and shaking in the sitting posture of medical transport nursing robots in medical scenarios. Due to the significant time-varying and uncertain load characteristics caused by patients' vital signs and behaviors, including strong randomness and non-linearity, high requirements are placed on the speed tracking accuracy and anti-interference ability of the robots. When developing high-performance decision-making and control algorithms for transport robots, the estimation of the mass of the seated human body and the shaking angle are basic parameters that must be considered. Due to the fact that the shaking of the seated human body can cause changes in the mass of the seated human body, there is a tight coupling problem, and the existing recognition algorithms for the shaking angle of the seated human body have insufficient adaptability to working conditions, which affects the accuracy and convergence speed of the estimation algorithm. However, existing research on incomplete wheeled robots mainly focuses on the analysis methods represented by Newton vector mechanics systems and Lagrange equations. However, there are still shortcomings in analyzing the uncertainty of the robot's internal dynamics model and external disturbances, especially in dealing with parameter mismatch and nonlinear oscillation problems. To address this issue, this paper proposes a dynamic modeling method based on the Lagrangian equation of the dissipation function. By incorporating threshold switching to improve the adaptive recursive least squares method and combining it with the adaptive unscented Kalman filtering algorithm, real-time adaptive estimation of human sitting posture mass and difficult to measure human body sway pitch angle is performed using drive wheel torque data. Through comparison between the pre - and post improvement algorithms, the improved estimation algorithm improves speed and accuracy.
Medical Transfer Nursing Robot; Human Sitting Posture; Parameter Estimation; Adaptive Unscented Kalman Filter.
A Review on the Dynamic Response Characteristics of Tunnels under Rayleigh Wave Excitation
As a significant component of seismic waves, Rayleigh waves exhibit strong surface energy concentration, wide propagation range, and high destructive potential, which pose critical threats to the safety and stability of shallow-buried tunnels. This paper reviews the dynamic response characteristics of tunnels subjected to Rayleigh waves. The formation mechanism, motion pattern, and energy distribution of Rayleigh waves are first introduced, followed by a systematic summary of their influence on tunnel structures. Existing studies reveal that the multi-directional particle motions induced by Rayleigh waves, coupled with the complex soil–structure interaction, can lead to bending, torsion, and non-uniform stress states in tunnel linings. Key influencing factors include burial depth, soil properties, and lining stiffness. While considerable progress has been achieved through theoretical analysis, numerical simulation, and shaking table tests, challenges remain in addressing complex geological conditions, three-dimensional irregular wave fields, and nonlinear soil–structure coupling. Future research should emphasize multi-scale experimental validation, the development of advanced numerical models, and the exploration of active control and seismic isolation measures, with the goal of enhancing tunnel safety and resilience under strong seismic events.
Rayleigh Waves; Tunnel Engineering; Dynamic Response; Soil–Structure Interaction; Seismic Performance.
Design of Pusher-Arm Structure and Service Reliability Research for Oilfield Small Repair Well Operation Robot
To address the issues of low efficiency in manual operation and high safety risks during the tripping operation of small workover tubing in oilfields, this study proposes a functionally integrated pusher arm structure. The lifting slide rail module enables precise Z-axis positioning, the two-stage rotating arm controls the horizontal trajectory, and the crank-slider hydraulic clamp performs adaptive grasping, achieving the fully automatic transportation of Ø73-339.7mm tubing from the catwalk to the wellhead. The study combines the theoretical mechanics model with finite element simulation to systematically verify the structural reliability of key components under a 1500N limit load. UG software is employed to build a three-dimensional model and optimize the sectional moment of inertia. ANSYS Workbench is utilized for static and transient dynamic analysis, and ADAMS-AMESim co-simulation is used to verify the dynamic performance. The results indicate that the 45-steel fixture has a maximum stress of 76.58 MPa (with a safety factor of 3.36), the Q235 rotating arm has a maximum stress of 36.78 MPa (with a safety factor of 4.2), and the positioning accuracy can reach ±5 mm. After integrating the system into a 40-ton workover rig, the manual intervention at the wellhead is reduced by 82%, and the time for tripping a single tubing is shortened from 4.5 minutes to 2.1 minutes, which provides key technical support for the automation of oilfield workover operations.
Minor Oilfield Workover; Pusher Arm; Structural Optimization; Finite Element Analysis; Electro-Mechanical-Hydraulic Coordination.
An Incremental Cost-Benefit Quantification Model for Passive Houses from a Multidimensional Value Perspective
This paper systematically examines the incremental costs and benefits of passive buildings across all lifecycle stages from a multidimensional value perspective, establishing an incremental cost-benefit assessment model encompassing economic, environmental, and social dimensions. A newly constructed public building in a cold region is used as a case study for validation analysis. The results demonstrate that the incremental benefits of this passive building project exceed its incremental costs throughout the lifecycle, exhibiting sound economic rationality and environmental-social value. The proposed assessment model and evaluation methodology provide theoretical support and a practical basis for green building investment decisions, project optimization design, and policy formulation.
Passive House; Incremental Cost; Cost-Benefit Analysis; Multidimensional Value.
An Optimization Method for DC Side Voltage Balance Control of HC-SVG based on Delay Signal Cancellation
Abstract: The integration of NPC high-voltage power units into HC-SVG systems introduces high harmonics in the DC capacitor voltage of the CHB unit and NPC DC bus side capacitor voltage, impacting device compensation performance. This study presents a comprehensive analysis of the DC side capacitor voltages of the CHB and NPC units, identifying and assessing their harmonic components. Subsequently, a filter scheme is devised utilizing the delay-cancellation method based on the triangle vector principle to optimize the DC voltage control of the CHB and NPC units. A simulation platform is constructed to validate the proposed theoretical framework. Results demonstrate that the optimized control strategy markedly enhances the compensation capabilities of HC-SVG systems, leading to a notable reduction in total harmonic distortion in both output voltage and compensation current under identical operational conditions, thereby enhancing the compensation performance of HC-SVG systems.
Hybrid Cascaded SVG; Harmonics; Fast Delay Signal Cancellation; Vector Triangle; Filter.
Static Load Testing and Mechanical Property Interpretation of RC Beams Strengthened with CFRP Plates
This paper explores the static behavior of reinforced concrete (RC) beams strengthened with prestressed CFRP plates through a combination of laboratory testing and finite element modeling. Three specimens were prepared: two strengthened beams employing different anchorage methods (rigid self-locking and force-card types) and one unstrengthened reference beam. The study focused on evaluating cracking load, ultimate bearing capacity, and deformation responses. The findings indicate that the use of prestressed CFRP plates markedly enhances beam performance. Specifically, the cracking load increased by about 60%, while the ultimate capacity improved by 32% and 50% for the respective anchorage systems. A high degree of deformation compatibility between the CFRP plates and concrete was observed. Strengthened beams displayed a denser crack pattern and better utilization of concrete strength, though accompanied by reduced ductility. The finite element simulations corroborated the experimental data and further highlighted the three distinct behavioral stages of the beams: elastic, cracking, and yielding. Overall, the research establishes a solid theoretical foundation for the application of prestressed CFRP plate reinforcement in engineering practice and demonstrates that the force-card anchorage system provides superior performance in stress transmission and failure mode control.
Prestressed CFRP Plates; Reinforced Concrete Beams; Static Behavior; Anchorage Methods; Structural Strengthening; Finite Element Modeling; Load-Bearing Enhancement; Crack Distribution.
Fuzzy Similarity based on Subtraction Set Pair Potential and its Applications
To address the issue where existing intuitionistic fuzzy set similarity measurement methods struggle to distinguish samples in several special data cases, a novel intuitionistic fuzzy similarity calculation method is proposed by delving into the dynamic characteristics among membership, hesitation, and non - membership degrees, and incorporating the subtraction set pair potential from the set pair analysis theory. The basic properties of intuitionistic fuzzy similarity are verified for this method. By calculating several special data cases to test its discriminability and comparing it with multiple existing measurement methods, results show that it effectively overcomes the problem of indistinguishable samples in special data cases. Furthermore, the traditional TOPSIS decision - making model is improved by presenting a pre - scoring TOPSIS model that integrates the subtraction set pair potential. Finally, the new intuitionistic fuzzy set similarity calculation method is combined with this model and applied to multi - attribute decision - making, demonstrating its reliability and effectiveness.
Intuitionistic Fuzzy Set; Similarity Measure; Connection Number; Subtraction Set Pair Potential; Multi-attribute Decision Making.
Research on Fault Diagnosis of UAV Acceleration Sensor based on GS-HPO-SVM
All articles must contain an abstract. The abstract text should be formatted using 10 point Times or Times New Roman and indented 25 mm from the left margin. Leave 10 mm space after the abstract before you begin the main text of your article, starting on the same page as the abstract. The abstract should give readers concise information about the content of the article and indicate the main results obtained and conclusions drawn. The abstract is not part of the text and should be complete in itself; no table numbers, figure numbers, references or displayed mathematical expressions should be included. It should be suitable for direct inclusion in abstracting services and should not normally exceed 200 words in a single paragraph. Since contemporary information-retrieval systems rely heavily on the content of titles and abstracts to identify relevant articles in literature searches, great care should be taken in constructing both.
Acceleration Sensor; Fault Diagnosis; Multi-domain Feature Extraction; Z-score Standardization; t-SNE Dimensionality Reduction; One-vs-All Encoding; Grid Search Hyperparameter Optimization; Support Vector Machine (SVM) Introduction.
A MEMS Accelerometer that Utilizes Both Series and Differential Modes
This paper presents an in-depth simulation analysis and optimized design of a MEMS accelerometer with a quadruple-cantilever structure, conducted using COMSOL Multiphysics. The simulation results reveal a fundamental mechanical characteristic: under acceleration load, the cantilever beam exhibits a strain distribution that is symmetric in magnitude but opposite in sign across its central axis (one side is under tensile strain while the other is under compressive strain). Leveraging this key insight, this study proposes an innovative series-parallel hybrid connection strategy. The four sensing elements on the two cantilevers are grouped according to their strain phases, enabling elements with identical strain to be connected in series for signal summation. The resultant anti-phase signals are then processed by a differential amplification circuit. This design successfully achieves two core advantages: firstly, through effective signal superposition and differential amplification, the final output signal amplitude is quadrupled compared to that of conventional single-ended accelerometers, significantly enhancing sensitivity. Secondly, the inherent common-mode rejection capability of the differential detection mechanism effectively suppresses environmental noise interference. This work provides a novel and effective solution for the design of high-sensitivity and high-robustness MEMS accelerometers.
MEMS Accelerometer; COMSOL; Quadruple Output.
Application of Predictive Control for Synchronous Motors in Oil Field Automation
For permanent magnet synchronous motor (PMSM) systems exhibiting strong coupling, parameter uncertainties, and dynamic load disturbances, this paper proposes a Model-Free Adaptive Control with Multi-Vector Predictive Current Control (MFAC-MPCC) framework, integrating Compact Form Dynamic Linearization MFAC (CFDL-MFAC) for the speed loop and triple-vector model predictive current control (MPCC) for the current loop. The hybrid architecture decouples adaptive speed regulation from high-precision current tracking, achieving robust performance without reliance on motor parameters. Key advantages include: (1) Model-free operation via CFDL-MFAC, dynamically linearizing the speed loop using only I/O data; (2) Enhanced disturbance rejection through real-time adaptive tuning; (3) Superior current tracking via triple-vector MPCC, minimizing steady-state errors and harmonic distortions. Simulation comparisons with traditional PI control and CFDL-MFAC approach validate the effectiveness and superiority of the proposed MFAC-MPCC scheme.
Oil Field Automation; Synchronous Motor; Triple-Vector MPCC; Speed Control.
A Review of Research on Human-Induced Vibration and Comfort of Pedestrian Bridges
With the increasing prevalence of long-span, lightweight pedestrian bridges, the issue of human-induced vibration has become increasingly prominent. This problem not only affects user comfort but may even compromise structural safety. This paper first analyses the generation mechanisms and characteristics of human-induced vibrations. It then summarizes pedestrian load models, vibration response analysis methods, and comfort evaluation criteria, while discussing the effectiveness of vibration reduction design strategies. Research indicates that the acceleration response of footbridges exhibits an initial increase followed by a decrease as crowd density rises, and that comfort assessment requires comprehensive consideration of both physiological and psychological factors. Finally, it is emphasized that establishing load models tailored to the characteristics of the Chinese population and optimizing vibration reduction technologies represent key future development directions.
Pedestrian Bridge; Human-induced Vibration; Comfort Assessment; Vibration Reduction Design; Crowd Load; Vibration Response.
Impact of Venturi-Effect Turbine Arrangements on Total Power Generation
Venturi ducts accelerate incoming flows through geometric contraction and thereby enhance the power output of individual hydro-turbines. Nevertheless, when multiple turbines operate in an array, wake effects can substantially re-duce the overall efficiency, making the layout a critical factor in plant performance. In this study, two-dimensional computational fluid dynamics simulations were conducted to compare the flow fields and aggregate power of five Venturi-assisted turbines arranged in either a straight line or a staggered configuration. Moreover, the influence of tail-to-head spacing (8.67, 10.00, and 11.33 m) was systematically examined. The results demonstrate that, in the straight-line lay-out, the centerline velocity of downstream turbines decreases by approximately 75% relative to the upstream turbine, yielding only a marginal increase in total power (from 6.55 kW to 6.73 kW). By contrast, the staggered layout generates inter-row acceleration corridors, leading to inflow velocities higher than the free stream for all turbines, while the total power decreases as spacing increases (from 47.19 kW to 44.01 kW). Overall, the staggered arrangement delivers nearly sevenfold higher total power (≈ 701%) compared with the straight-line case. These findings highlight that staggered configurations with controlled inter-row spacing are essential for maximizing the efficiency of Venturi-turbine arrays, thereby providing theoretical guidance for the design of underwater power plants.
Venturi Effect Turbine; Turbine Array Layout; Wake Effects; Staggered Configuration; CFD.
Research on Benefit Distribution in Pallet Pooling Alliances based on an Improved Shapley Value
Against the backdrop of dual carbon goals, pallet pooling alliances have emerged as a crucial solution to address severe pallet wastage, extremely low utilization rates, and inadequate standardization. This paper analyzes the operational model of pallet pooling alliances, fully considers their characteristics, proposes an improved Shapley value benefit distribution model, and analyzes and verifies the model's effectiveness and rationality. Results indicate that the improved benefit distribution model can satisfy the benchmark rates of return for different stakeholders while fully considering the impact of factors such as resource investment, risk bearing, and actual contributions on benefit distribution within pallet pooling alliances. This provides valuable reference for promoting the development of pallet pooling alliances.
Pallet Pooling Alliance; Cooperative Game; Benefit Distribution; Shapley Value.
The Application of 5G Communication Technology in Intelligent Transportation Systems
With the continuous development of communication technology, 5G technology has been widely applied in all aspects. In China, where a vast population base translates into high travel demands and severe traffic congestion, intelligent transportation systems (ITS) emerge as a crucial solution. This paper delves into the integration of 5G and ITS, exploring the application of 5G technology in this vital field through literature review and case analysis. It meticulously examines the specific applications of 5G in three key areas: autonomous driving, traffic management, and intelligent travel services. Moreover, it addresses the challenges faced by 5G in this domain, along with potential countermeasures and future development trends. Leveraging its technical attributes of extensive connectivity, large capacity, high speed, and low latency, 5G technology significantly enhances the reliability, safety, and efficiency of intelligent transportation systems. It has not only propelled the development of ITS but also laid a solid foundation for constructing an efficient, safe, and sustainable urban transportation environment.
5G Communication Technology; Intelligent Transportation System; Autonomous Driving; Traffic Management; Intelligent Travel Service.
Research on Urbanization Process of Zhanjiang City's Municipal Area based on Remote Sensing Information
The data source mainly used is landsat TM/OLI image, and the application supervision supervised method is used to extract the urban construction land information of Zhanjiang City area in 2000, 2005, 2010 and 2015, combined with Zhanjiang Yearbook data. Analyze its temporal and spatial variation characteristics and its driving force. The research results show that: (1) The construction land of Zhanjiang City has increased from 18.43 square kilometers to 163.90 square kilometers. (2) Urbanization showed internal development from 2000 to 2010 and expanded outward from 2010 to 2015. (3) The driving factors of urbanization are mainly population growth, government policies,and population growth.
Zhanjiang City; Remote Sensing Image; Driving Force; Building Land; Time and Space Changes.
Current Status of Research on Buried Gas Pipelines Containing Crack Defects
In China's energy structure, oil and gas occupy an important position. Due to the multiple limitations of oil reserves, environmental protection policies and social demand, clean energy such as natural gas has been widely used, of which buried pipelines have become one of the main ways of natural gas transmission. Defective pipelines containing cracks are an important cause of pipeline failure accidents in recent years, posing an important threat to the safe operation of buried pipelines. In this paper, from the three aspects of pipeline crack detection methods, pipeline cracking, and failure analysis and remaining life, the relevant research results of buried pipelines in recent years are sorted out, and further prospects for the subsequent research direction are proposed.
Buried Pipeline; Crack Defects; Numerical Simulation; Remaining Service Life.
Application of Ion Beam Etching in the Micro-LED Process
As an emerging display technology, GaN-based micron-scale light-emitting diodes (Micro-LEDs) possess broad application potential and have undergone rapid development in recent years. However, as device dimensions scale down, the fabrication yield of Micro-LEDs decreases significantly, primarily attributable to increased process complexity. This paper analyzes the issue of metal residue (commonly known as "metal fences") caused by metal etching during the Micro-LED manufacturing process. The effect of different etching angles on the removal efficiency of these metal residues was evaluated experimentally. The results indicate that the cleaning efficiency of metal residue per unit time is optimized when the ion beam etching angle is set to 140°.
Micro-LED; Ion Beam Etching (IBE); Metal Residue.
Study on Pressure Relief Technology Using Hydraulic Fracturing in Hard Roof Strata at Guqiao Mine
During the mining of the adjacent working face at Guqiao Mine 1315(1), the hard roof proved difficult to collapse, leading to significant stress concentration in the coal pillars near the roadway. This study analyzes the causes of stress concentration in the coal pillars and proposes hydraulic fracturing and roof cutting as a mitigation method. Numerical simulations were conducted to determine the optimal roof-cutting angle and depth, followed by field trials. The results demonstrate that hydraulic fracturing effectively reduces stress on the coal pillar side and promotes roof caving in the goaf. A roof-cutting height of 28 m and an angle of 60° were found to be the most effective, shifting the stress concentration zone to 3.8 m from the 1315(1) track gateway, with a peak stress of 38.4 MPa-a reduction of 9.7 MPa or 20.1% compared to the scenario without roof cutting. The industrial application, guided by the simulated angle, yielded satisfactory outcomes.
Hard Roof; Hydraulic Fracturing; Roof Cutting; Numerical Simulation.
A Review on Guided Wave-Based Damage Detection of Concrete-Filled Steel Tubular Structures
Concrete-filled steel tubular (CFST) structures are widely applied in bridges, buildings, and seismic engineering owing to their excellent load-bearing capacity, ductility, and construction efficiency. However, during service, CFST structures are prone to multiple types of damage, such as crack propagation, interfacial debonding, and steel tube corrosion, which severely threaten their safety and durability. In recent years, guided wave technology has gradually become an important approach for structural health monitoring of CFST structures, owing to its long-range propagation capability, high sensitivity to minor damage, and feasibility for online monitoring. This paper systematically reviews the research progress on guided wave applications in CFST structures, including propagation mechanisms, typical damage detection methods, signal processing, and intelligent recognition techniques. Particular attention is given to monitoring strategies for cracks, debonding, and corrosion. Furthermore, challenges and development trends of guided wave-based damage detection in CFST applications are summarized, highlighting the urgent need for breakthroughs in multi-mode guided wave mechanisms, integration with artificial intelligence methods, adaptability to complex environments, and engineering implementation. This review aims to provide valuable references for nondestructive evaluation and health monitoring of CFST structures.
CFST; Guided Wave Technology; Damage Detection; Interfacial Debonding; Artificial Intelligence.
A Review of Recent Advances in Temperature-Dependent Constitutive Models and Ductile Fracture Models for Advanced High-Strength Steels in Automotive Applications
Lightweight design is a global trend in the automotive industry. The extensive application of advanced high-strength steel in automobiles enables lightweight design, while its higher tensile strength ensures the safety of vehicle passengers. However, advanced high-strength steel suffers from defects such as edge cracking and spring-back during cold forming, which hinders its extensive application in automotive manufacturing. Thus, numerous researchers have incorporated temperature control into the forming process of advanced high-strength steels and found that this approach effectively enhances their formability without compromising tensile strength. Investigating temperature-dependent constitutive models and ductile fracture criteria for advanced high-strength steels can facilitate better understanding of their deformation behavior and more accurate cracking prediction, thus broadening their application prospects. Currently, temperature-dependent constitutive models and ductile fracture criteria for advanced high-strength steels are primarily categorized into two types: macroscopic and microscopic approaches. The macroscopic approach involves performing uniaxial tensile and other basic mechanical tests or constructing constitutive models that describe the stress-strain response through combining piecewise function fitting with continuum mechanics. On the microscopic scale, research primarily involves observing dislocation density, lattice distortion, grain orientation, etc., and constructing constitutive models that reveal deformation mechanisms and structural evolution laws by integrating dislocation dynamics and phase transition theory. Taking advanced high-strength steels as the research object, this paper reviews the current state of temperature-dependent constitutive models and analyzes three typical ductile fracture criteria.
Lightweighting; Advanced High-strength Steels; Warm Forming; Temperature-dependent Constitutive Modeling; Temperature-dependent Ductile Fracture Modeling.
A Review of YOLO Series Algorithms in Object Detection for UAV Aerial Images
With the rapid development of the low-altitude economy, the demand for object detection in UAV aerial images has become increasingly urgent in fields such as traffic monitoring, agricultural plant protection, and emergency rescue. The YOLO series algorithms have become the mainstream technology in this field due to their advantages of single-stage end-to-end detection. However, the characteristics of UAV aerial scenes, such as extremely small target scales, dense distribution, complex backgrounds, and variable attitudes, pose severe challenges to the accuracy and real-time performance of the algorithms. This paper systematically sorts out the evolution of YOLO series algorithms, from the pioneering exploration of YOLOv1 to the Transformer architecture innovation of YOLOv12, and analyzes the core improvements of each version in terms of anchor box mechanism, feature fusion, and detection head design. It focuses on discussing the difficulties faced by YOLO algorithms in UAV aerial scenes, such as insufficient detection accuracy of small targets, complex scale distribution, and the contradiction between real-time performance and accuracy, and summarizes the key technical solutions for feature extraction, network lightweighting, detection head optimization, and loss function improvement. Meanwhile, it introduces the characteristics of mainstream datasets such as StanfordDrone and VisDrone2019. The research aims to provide relevant scholars with the research status and development context in the field of object detection in UAV aerial images, and offer references for subsequent algorithm optimization and application implementation.
Aerial Images; Object Detection; YOLO; Dataset.
Reservoir Geological Characteristics in the Middle Section of the Third Member of Shahejie Formation, Block S, Dongying Sag, Bohai Bay Basin
The reservoir in the middle section of the third member of Shahejie formation in Block S is characterized by large burial depth, tight reservoir properties, and unclear oil-water distribution features. Through the implementation of zone division and correlation, 3D seismic interpretation, sedimentary facies identification and distribution analysis, as well as micro and macro reservoir descriptions, this paper systematically grasps oil-water distribution characteristics and hydrocarbon enrichment regularities, and clarifies the main controlling factors of hydrocarbon accumulation. The research results show that: ① Objective reservoir is divided into six units based on two control markers and two auxiliary markers, with main oil accumulation occurring in M3 and M4. ② Internal structures are characterized by westward-dipping monoclines sandwiched between southern and northern fault zones. Although the distribution of oil-bearing layers is not controlled by these structures within the area (as it is a lithological reservoir), fault zones outside the area play a role in sedimentation and hydrocarbon accumulation. ③ Reservoir system belongs to semi-deep lake-deep lake turbidite fan with deep burial depth, low porosity, low permeability. High-quality reservoirs are mainly distributed in turbidite channels. This study can provide reference for reservoir development in block S.
Dongying Sag; Turbidite Fan; Lithologic Reservoir; Hydrocarbon Enrichment Regularities; Main Controlling Factors of Hydrocarbon Accumulation.
Impact of Temperature Cracks on the Toughness and Load-Bearing Performance of Structural Components
A simulation of the shear performance of four simply supported beams with existing thermal cracks was conducted. The study investigated the influence of different crack locations and different load positions on the stress intensity factor of the existing thermal cracks. The results indicate that thermal cracks in the midspan of the beam are more likely to propagate new cracks. The smaller the load-to-shear span ratio, the higher the likelihood of the existing thermal cracks continuing to expand. For thermal cracks in the midspan, the possibility of developing into Mode II cracks (shear mode) is relatively high.
Thermal Cracks; Finite Element Analysis; Stress Intensity Factor.
Stability Analysis of Soft Rock Slope Considering Seepage Softening and Damage Effects
The geological disasters of soft rock slope instability are more and more concerned by the engineering community. Rainfall infiltration is an important factor inducing its instability. In order to analyze the change process of the dynamic stability of soft rock slopes under different rainfall conditions, an analysis method considering soft rock damage-softening-seepage effect is proposed for soft rock seepage softening and damage effects. Variation of slope seepage characteristics, stability and plastic zone distribution. The results show that soft rock slopes are mainly affected by unsaturated seepage effects during the early rainfall period. The softening effects in the transient saturated zone gradually deepen the slope stability with the extension of the softening time. The value increases gradually. Long-term light rain is more likely to cause slope instability than short-time heavy rain, and the stability has a "response delay" phenomenon. The stability coefficient and plastic failure zone of soft rock slopes are affected by both unsaturated seepage and softening effects. They gradually change from the local instability controlled by the cover of the slope to the overall instability controlled by the softening effect of soft rocks. The calculation results considering the seepage softening and damage effects of soft rocks will be more in line with the actual situation, which can provide reference value for the seepage stability management of soft rock slopes.
Road Engineering; Soft Rock Slope; Seepage; Damage Effect; Softening Effect.