Failure analysis of silane trailer pipeline based on chloride-induced pitting corrosionYu, Ting; Wu, Kaifei; Song, Chao; Jin, Nan; Zhong, Fengping; Huang, Liuyi; Ying, Chenkai
doi: 10.1117/12.3108456pmid: N/A
The study gives a complete failure analysis of two leaking parts - a valve guide pipe and a tee fitting - from a silane trailer pipeline system that is made of 316 austenitic stainless steel. Investigation used multi-technology means including industrial computed tomography (CT), macro/micro observation, scanning electronic microscopy combined with energy-dispersion X-ray spectrum technology (SEM/EDS), metallography, chemical component analysis, and hardness test. The results show that the leakage was due to chloride ion (pitting corrosion) attack from inner wall to outer wall of pipe, the propagation of corrosion pits is preferred on grain boundaries, and then leads to through-wall perforation. Both components material composition met the 316 standard, microstructure, weld quality, hardness distribution were all normal, ruling out material defects and large residual stress as main reasons. The same corrosion morphology, with the exclusive occurrence of chlorine at key locations, clearly points to the introduction of chloride containing impurities into the medium during operation as creating a localized aggressive environment, resulting in an autocatalytic pitting attack. So this failure is an environmentally-assisted localized corrosion event. This study underscores how important it is to have medium purity that is strictly controlled and protected against chloride contamination during maintenance and operation of a system for transporting high purity gas.
Design and implementation of an automatic feeding manipulator with a combined clamping-pushing mechanismGuo, Weili; Wang, Lulu
doi: 10.1117/12.3108648pmid: N/A
This paper addresses the problems of small clamping contact area, poor stability and potential workpiece damage during the loading process of existing robotic arms, and proposes a new type of integrated clamping and pushing loading robotic arm design. This device, through the coordination of an electric slide table, an electric push rod and a multi-link clamping mechanism, utilizes symmetrically arranged "V"-shaped links and an internal reciprocating screw - bevel gear system to achieve self-adaptive clamping during the downward movement of the robotic arm and reliable holding during the upward movement. To enhance clamping stability, replaceable clamping plates are designed to increase the contact area. At the same time, combined with ratchet-toothed rack unidirectional transmission, the control logic for downward clamping and upward locking is simplified. Additionally, a spring - telescopic rod buffer mechanism is set up within the clamping unit to ensure the stable and static holding of the sheet after clamping, avoiding possible surface wear of the workpiece. Research shows that the designed robotic arm structure is stable and can reliably complete clamping, pushing and automatic release, thereby improving the automation level and operational safety of the loading process.
Molecular dynamics simulation of the alkali activation process in geopolymersLi, Wei; Cao, Youcai; Li, Yuanhao; Wang, Quan; Wang, Yali; Yang, Jian; Jiao, Yiwei
doi: 10.1117/12.3106430pmid: N/A
The rapid evolution of computational materials science has enabled the emergence of a multi-scale research paradigm, wherein molecular dynamics (MD) simulation serves as a robust technical tool for elucidating reaction pathways and establishing structure-performance relationships. In this study, we systematically employ MD simulation to investigate the intricate connection between microstructural evolution during geopolymer alkali activation and its corresponding macroscale mechanical properties. By leveraging multi-scale simulation methodologies, we successfully identify the key molecular entities orchestrating the alkali activation reactions in geopolymerization. These findings not only provide a profound theoretical foundation for the design and optimization of high-performance silicon-aluminum cementitious materials but also hold significant academic value and practical implications. They contribute to the resourceful utilization of solid waste and foster the advancement of low-carbon construction materials, aligning with global sustainability goals and promoting environmentally friendly engineering practices.
Design and optimization of elliptical guide vane based on CFDYou, Qiqing; Zhang, Baoji
doi: 10.1117/12.3107876pmid: N/A
The Pre-swirl Fairing in Front of Propeller (PFFP) is a widely used hydrodynamic energy-saving device for ships. It mitigates wake flow separation at the stern, reduces vessel resistance, and ensures a more uniform wake flow field, thereby minimizing the impact of propeller-generated vortices on navigation performance. PFFP has been widely used on various operating ships, and from actual navigation data, it has shown that it has a certain energy-saving effect. The design of PFFP should fully consider the influence of stern line characteristics on resistance and propulsion performance. This article designs an elliptical guide cover for a bulk carrier with a U-shaped stern, and takes the outlet radius of the guide cover, the angle of attack of the guide pipe, the chord length of the guide pipe, the angle of attack of the stator, and the chord length of the stator as design parameters. The CFD method is used to calculate the shaft power as the target speed, and an automatic optimization platform is built using Solidworks deformation control software and optimization algorithm to carry out optimization design. Finally, the PFFP with the best energy-saving effect is obtained.
Online dynamic parameter estimation of MIMO plants based on particle swarm optimizationLiu, Jiaxu; Jie, Xinchun
doi: 10.1117/12.3100770pmid: N/A
In industrial control, the time-varying characteristics of multi-input multi-output (MIMO) systems cause model variations. If system parameters cannot be accurately estimated in real time and control strategies dynamically adjusted, the control accuracy, stability, and even production safety will be directly affected. To address this issue, a parameter online estimation method based on multi-step sampling and particle swarm optimization (PSO) is proposed. In each control cycle, the controller acquires the input/output data of the MIMO physical plant through multi-step sampling, and the PSO algorithm is employed to achieve online identification of the dynamic parameters of the MIMO system. The identified model parameters are then used to update the control law of the controller, enabling dynamic closed-loop control of the time-varying system. In the simulation of a time-varying coupled MIMO process, the proposed multi-step sampling and PSO-based scheme maintained stable modeling precision under simultaneous variations of multiple parameters. Its real-time estimation ability ensured timely tracking and reliable feedback for subsequent closed-loop control, confirming the practicality of the approach.
Research on the networking method of miter gate structures health monitoring points in ship locks based on vibration responseWang, Junwen; Cai, Jinyi; An, Xiaogang
doi: 10.1117/12.3107980pmid: N/A
As a large metal structure, ship lock miter gate has the characteristics of large volume, heavy weight, and long-term underwater operation of part of the gate body. It is in complex working conditions such as frequent opening and closing, alternating water level difference, current impact and ship collision for a long time. Miter gate faces aging and damage problems, which brings potential risks to shipping safety. Therefore, it is necessary to carry out real-time health monitoring of miter gate structure. However, traditional monitoring networking methods mostly rely on empirical distribution, and there are some problems such as redundancy of measuring points and overlapping information, and there is a lack of focused monitoring methods according to the actual situation of structural damage. Therefore, this paper proposes a network method of health monitoring points of ship lock miter gate based on vibration response, and constructs a vibration monitoring model of ship lock miter gate structure. Through the simulation data verification, this method can realize the dynamic optimization of monitoring point networking, and provide theoretical support and practical path for lightweight, cost-effective and efficient health monitoring of ship lock miter gate.
Design and analysis of a novel octopod sliding chassisHuang, Xionghui; Fu, Shixi; Chen, Yue; Cun, Yihui; Yu, Gang; Xu, Wuhui; Li, Qiang
doi: 10.1117/12.3097988pmid: N/A
In order to improve the work efficiency of the imitation manual digging robot, a novel octopod sliding chassis is specially designed to achieve efficient collaborative operation. The sliding chassis adopts a frame structure, and the octopod legs are driven by luffing cylinders, which can smoothly complete the sliding operation. In addition, the chassis is equipped with a telescopic device, which can flexibly adjust the height according to different road conditions to ensure a smooth ride on various road surfaces. Wheels are mounted on the base for quick movement on flat ground. The chassis frame is divided into two parts, each of which is equipped with outriggers and moves laterally and longitudinally by means of slewing rings. Through 3D modeling and finite element analysis, the structural strength and stability of the skid steer carrier are verified to ensure that it can meet the operational needs of the drilling robot, so as to achieve efficient collaborative work.
Performance optimization of PZT-based thin films for piezoelectric vibration energy harvesting via multi-ion doping and heterogeneous film designSong, Yihui; Wu, Pengfan; Li, Jizhen; Yang, Danni; Mu, Xiaojing; Wu, Liangke
doi: 10.1117/12.3105809pmid: N/A
As the core transducer media, piezoelectric materials directly determine the output performance of the energy harvesters. The preparation process and property regulation methods are key technologies in the field of piezoelectric transduction. Compared with common piezoelectric materials such as PVDF, ZnO and AlN, lead zirconate titanate (PZT)-based thin films has attracted significant attention due to their excellent property. However, the current PZT films face challenges of low-transduction efficiency and lacking of diverse control strategies, which limit the output performance and applications. Hence, this study proposes a synergistic regulation strategy combining multi-ion doping and heterogeneous film design. Through a systematic investigation of properties of films with varying La and Ba doping concentrations, the optimal co-doping concentration was determined to be 2% for La³⁺ and 2% for Ba²⁺. The P1.06L0.02B0.02ZT film with this composition exhibited the optimal piezoelectric performance. By constructing a P1.06L0.02B0.02ZT/PZT composite structure and rationally regulating the material composition and thickness of each layer, the interfacial stress caused by mismatching of thermal expansion coefficient is effectively reduced, thereby suppressing the generation of cracks and defects. The interaction between different layers also promotes the synergistic enhancement of interfacial polarization and the coupling effect of seepage stress. The optimized PZT film demonstrates a remarkable enhancement in piezoelectric performance, achieving a piezoelectric coefficient (d₃₃) of 269.7 pC/N and a piezoelectric voltage constant (g₃₃) of 0.3454 V·m/N, representing significant improvements of 54.29% and 65.11% compared to PZT film. This study provides a new method for the performance optimization of PZT thin films.
Research on investment strategies for integrated photovoltaic-storage-charging systems based on particle swarm optimizationZhou, Mi; Zhuang, Jun; Cai, Jianliang; Wang, Ruiyan
doi: 10.1117/12.3106838pmid: N/A
To address issues such as capacity allocation imbalance, low economic efficiency, and insufficient reliability caused by unreasonable investment decisions in PV-charging-storage systems under the context of high penetration of distributed photovoltaics and rapid adoption of electric vehicles, this paper conducts research on optimized investment strategies for PV-charging-storage systems. Firstly, a PV-charging-storage collaborative system model is constructed, including PV modules, charging piles, energy storage systems, and distribution networks, clarifying the energy conversion relationships and constraints of each device. With the minimization of long-term lifecycle costs as the core objective, while also considering power supply reliability and green power utilization, and taking into account uncertainties such as PV output fluctuations, random user charging behavior, and electricity price policies, a multi-constraint optimization model is established that includes device investment, operation and maintenance, losses, and electricity shortage penalty costs. The model is solved using the Particle Swarm Optimization (PSO) algorithm to obtain multiple capacity allocation schemes, and the schemes are screened based on meeting the system optimization objectives to derive the optimal capacity allocation scheme. Finally, case simulations verify the effectiveness of the proposed model and method. The results show that the optimized investment strategy significantly reduces the life cycle costs compared to traditional plans, validating the effectiveness of the proposed strategy. This provides a decision-making basis for scientifically planning investments in PV-charging-storage systems and has practical significance for improving the economic benefits of distributed energy, power supply reliability, and the consumption of clean energy.
Analysis and diagnosis of common faults in mining tunneling machinesZhang, Lei
doi: 10.1117/12.3109951pmid: N/A
As the main engineering machinery and equipment for excavation and soil expansion, the tunnel boring machine can be used not only for the excavation of ground engineering tunnels, but also for the mining of underground mineral resources. However, due to harsh operating conditions and environments, tunnel boring machines often experience various failures, which hinders the normal and orderly progress of tunneling operations. This article analyzes the structural principles of mining tunnel boring machines and combines the usage environment of mining tunnel boring machines. It lists common problems that occur with mining tunnel boring machines in actual production activities. It analyzes and categorizes common fault types, as well as troubleshooting and diagnosis. This method not only provides convenience for production maintenance activities, but also provides a reference basis for fault diagnosis of other types of construction machinery and equipment.