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This specification covers a corrosion- and heat-resistant nickel alloy in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
This specification covers a corrosion-resistant steel in the form of bars, wire, forgings, extrusions, flash-welded rings, and stock for forging, extruding, or flash-welded rings.
AMS F Corrosion and Heat Resistant Alloys Committee
This specification covers a corrosion- and heat-resistant nickel alloy in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
This specification covers a nitriding grade of premium aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. AMS6496 and AMS6498 cover UNS K23280 with other quality levels.
AMS E Carbon and Low Alloy Steels Committee
This specification covers a manganese bronze alloy in the form of sand and centrifugal castings (see 8.5).
AMS D Nonferrous Alloys Committee
This specification covers a corrosion- and heat-resistant steel in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
This specification covers a corrosion- and heat-resistant steel in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
This specification covers a corrosion- and heat-resistant nickel alloy in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
This specification covers an iron-nickel alloy in the form of strip 0.020 to 0.250 inch (0.51 to 6.35 mm), inclusive, in nominal thickness.
AMS F Corrosion and Heat Resistant Alloys Committee
This specification covers a gold-palladium-nickel alloy in the form of wire, rod, sheet, strip, foil, pig, powder, shot, chips, preforms, and a viscous mixture (paste) of the powder in a suitable binder.
AMS F Corrosion and Heat Resistant Alloys Committee
This paper studies the applicability of the CDTire tire model in vehicle comfort and durability simulations by comparing it with the FTire tire model. Based on a physical 250/50 R19 tire, the corresponding CDTire and FTire models are developed and integrated into a multibody dynamics model of an SUV. After simulations of two handling comfort conditions and one durability condition using the CDTire and FTire models, it is found that, when FTire is used as the base case, CDTire produces a smaller relative error in vehicle comfort simulation, with a maximum of +5.6%. In the durability simulation, the relative error is larger, but the maximum value remains within ±10% at + 9.7%. Therefore, it can be concluded that CDTire is one tire model with acceptable simulation accuracy for vehicle comfort and durability.
Gao, FenglingWu, WenwenGeng, Hao
Aircraft assembly systems, as a critical phase in aerospace manufacturing, face significant challenges in maintaining production efficiency and ensuring product quality. This complex manufacturing system exhibits two distinct characteristics: (1) tightly coupled interactions among manufacturing elements involving process sequences, material flows, and equipment utilization; and (2) dynamic resource allocation and material distribution plans. The inherent variability in production element configurations often leads to operational instability and schedule deviations, which may result in abnormal production states. To address these challenges, this study proposes a data-driven predictive framework that integrates Long Short-Term Memory (LSTM) neural networks with multi-criteria evaluation. The developed LSTM-based model effectively forecasts two critical production indicators of cycle time and balance rate, achieving temporal prediction through historical operational data analysis. The proposed methodology facilitates timely anomaly detection and early warning, allowing proactive risk mitigation and ensuring sustained production system stability. This research contributes to advancing intelligent monitoring and control strategies for aircraft assembly operations within data-driven manufacturing environments.
Chen, BolinWu, JunjieSun, JinfengWang, Kai
Manual operations in traditional tea packaging lines often suffer from low productivity, safety risks, and inconsistent labeling quality. To overcome these limitations, this study develops a fully automated tea packaging system guided by an improved genetic algorithm. The system integrates five functional modules—bag feeding, bag opening, material filling, sealing, and labeling—into a seamless workflow. By applying the optimization capability of the improved genetic algorithm, the system achieves better coordination among modules, higher adaptability to different bag shapes and sizes, and improved operational efficiency. Experimental validation demonstrates that the proposed design not only simplifies the packaging procedure but also enhances precision, reliability, and production speed. The system provides a flexible and intelligent solution applicable to a wide range of tea packaging requirements.
Guo, HuiZhao, ZhikaiYuan, WeilongLin, LinYu, YunchangGao, Jiashun
In the marine environment, navigation safety and operational effectiveness depend heavily on the precision of liquid level/capacity measurement equipment and systems. In order to examine their measurement accuracy under complex operational situations, including ship navigation states and water tank sloshing, this study employed computational fluid dynamics (CFD) methodologies. The numerical technique performs a thorough examination of how various operating conditions impact measurement accuracy and integrates the volume of fluid (VOF) model and laminar flow model with appropriately defined boundary conditions and solver settings. The findings indicate that constant-speed navigation has minimal impact on accuracy, horizontal acceleration causes moderate deviations, and accelerated diving greatly reduces precision. The amplitude of water tank sloshing has a positive correlation with measurement error. When sloshing amplitudes are less than 1 m, the integration of the resulting acceleration efficiently lowers deviations while preserving excellent accuracy. In light of these results, we advise adding accelerometers to differential pressure transmitters to improve measurement precision. This investigation provides data-driven references and technical solutions for system design and operational standard formulation in marine measurement systems.
Shang, JinQin, ZimingWang, YingweiWu, ChaoZhao, FenggangChen, LiangXia, WeiYan, JinChen, MinChen, Guoao
To precisely simulate the nonlinear dynamic characteristics of a robotic arm grasping cylindrical objects from storage units, this study establishes a dynamic model of the robotic grasping process incorporating Coulomb and viscous friction models to characterize frictional properties. Furthermore, to effectively identify unknown parameters in the dynamic model, a parameter identification method based on the Superb Fairy-wren Optimization Algorithm (SFOA) is proposed. The root-mean-square error (RMSE) between the displacement responses from the dynamic model and the experimentally acquired displacement data serves as the optimization objective. Multiple sets of experimental data are utilized to identify the unknown parameters of the dynamic model. The results demonstrate that when the identified parameters are applied to the dynamic model, the goodness-of-fit between the model’s response displacement data and the experimental displacement data exceeds 0.999. This validates the effectiveness and accuracy of the proposed method for identifying unknown parameters in dynamic models.
Shen, ShaofengYang, LiuWang, ZihanHan, Qunyi
During root canal treatment, dentists must use endodontic access cavity preparation dental handpieces and root canal preparation handpieces separately for endodontic access cavity preparation and root canal preparation. To reduce the use of surgical tools, an integrated instrument for endodontic access cavity preparation and root canal preparation was designed. Driven by an air impeller and equipped with a quick tool disassembly unit, the instrument realizes forward or reverse rotation of the end tool via an STM32-controlled electromagnetic directional valve. The flow characteristics of the air impeller system were analyzed using ANSYS CFX, and the results showed that the impeller output torque met the design requirements. To minimize torque fluctuations during rotation, a double-layer offset impeller structure with an offset angle of 14° was designed based on the flow characteristics of the impeller system. The instrument was applied in simulated endodontic access cavity preparation and root canal preparation experiments. Preliminary experimental results demonstrate the feasibility of using this integrated instrument for both endodontic access cavity preparation and root canal preparation.
Chen, GuoliangXu, Kunlang
In view of the practical problem that the air-conditioner outdoor units in the spacecraft test workshops of coastal launch sites are severely damaged under the influence of super typhoon, this paper employs the finite-element simulation method to establish a finite-element model of the outdoor units. The implicit Euler solution method is used to calculate the stress conditions of each component of the unit under the influence of typhoons with wind speeds of 50.9 m/s and 61.2 m/s respectively. By combining with the material yield strength, the weak links in the design are identified, and targeted improvement measures are proposed. The simulation results demonstrate good agreement with the actual impact of the typhoon, which can effectively guide the typhoon-resistance optimization design of subsequent air-conditioning units.
Gu, YufeiChen, ShaojiangShi, YunShanFu, YuanmingChen, XiYang, Degang
Composite hollow core station post insulators utilize fiber-reinforced epoxy resin as the core rod material, offering advantages such as high specific strength, high specific stiffness, and excellent fatigue resistance. This enables them to effectively meet the flexible, variable, and complex operational demands of modern power systems. However, composite materials exhibit anisotropic characteristics, resulting in complex mechanical properties. Additionally, the core rod of hollow pillar composite insulators is typically fabricated through a spiral-plus-circumferential winding process, which significantly complicates structural design and computational analysis. This study establishes a finite element model of the hollow pillar composite insulator core rod in ABAQUS. It analyzes the influence of fiber content on composite material parameters and performs finite element numerical calculations to examine the stress state of core rods with different winding angles under compressive and bending loads. The research findings provide theoretical support for the optimized structural design of hollow pillar composite insulator core rods.
Liu, JianbiaoDu, YijunQuan, XiaoxiZhou, Songsong
This study explored the relationship between the placement roller and the radius of curvature of the mold. In the production process, it is better to judge the feasibility of placement based on the actual placement profile. It is calculated that when the prepreg with a tow width of 6.35 mm is used for automatic fiber placement and forming, the 4-tow, 8-tow, and 16-tow laying rollers can be laid at a maximum depth of 2 mm. The formulas for the length of the automatic fiber placement roller and the axial radius of curvature of the die are obtained. At the same time, through geometric analysis, a formula for calculating the minimum radius of curvature of the pressure roller is obtained. The finite element software Abaqus was used to simulate the contact of the 4-tow, 8-tow, and 16-tow laying rollers with the minimum axial critical radius of curvature at a 2 mm depth, and output the force curve of the node where the mold surface contacts the pressure roller. It is found that the simulation results are consistent with the calculation results.
Ma, ChengXiu, ZhifengXue, HongmingYang, MaoweiZhang, Pin
Based on the improved genetic optimization, a new Stewart platform optimization design method is proposed in this paper. Through introducing chaotic mapping and simulation annealing strategy, combining the kinematic analysis of the Stewart platform and the constraint conditions of the workspace, aiming at maximizing the workspace and minimizing the motion error, the structural parameters of the platform are optimized. The experimental results show that the improved GA significantly improves the workspace and motion performance of the Stewart platform compared with the traditional ant colony optimization and basic genetic optimization.
Zhu, MingWang, Baichao
Under cyclic ultra-high-pressure impact loads, structures often experience local fractures due to insufficient initial fatigue life (low-cycle fatigue). This article focused on a certain ultra-high-pressure support structure and established a dynamic model based on load transfer characteristics to simulate the transient stress-strain response under impact loads. On this basis, a low-cycle fatigue life evaluation method was used to predict the fatigue life of the structure about 362 times, which was significantly different from the required indicators for structural fatigue life. In response to the problem of high loadbearing capacity on the structural support surface and significant stress concentration at the root, the structural load-bearing method has been optimized. Calculation analysis showed that after optimization, the structural stress was greatly improved, the bearing capacity of the support surface was reduced by 25 %, and the fatigue life of the structure was increased from 362 times to 4208 times, an increase of about 10 times. The optimized structure has been verified through 2000 tests without any fracture, meeting the requirements for the service life of the structure.
Wang, ShumanNing, BianfangMa, AminZhang, Fanfan
Recent advances in precision motion technology have heightened the requirement for precise stiffness analysis in flexible mechanisms. This paper begins with a theoretical analysis, constructing a mathematical expression for the stiffness of flexible mechanisms, providing a systematic framework for analysis. Subsequently, the study employed finite element analysis on both single and double parallelogram flexible mechanisms to validate the proposed theoretical stiffness formulas. This process not only confirmed the effectiveness of the proposed expressions but also highlighted the influence of different structures on stiffness characteristics. The finite element analysis results validate the proposed theoretical model as an effective and reliable tool for predicting the stiffness of flexible mechanisms. By establishing a reliable predictive model, this research paves the way for the informed design and systematic optimization of next-generation flexible mechanisms in precision motion engineering.
Cai, Dongchen
To address the challenge of accurately assessing the reliability of complex equipment, a reliability evaluation system for a five-axis machining center was developed based on extension theory. By collecting and analyzing the failure modes and data of various subsystems, the strengths of the Fuzzy Analytic Hierarchy Process (FAHP) and the Entropy Weight Method (EWM) were combined to determine the weight of reliability evaluation indicators for both the machining center and its subsystems. A comprehensive assessment of the five-axis machining center's overall reliability was conducted. According to the principle of maximum membership, the reliability grades for the spindle system and the feed system were both rated as “excellent.”
Fei, ShouxiangWang, DechaoPiao, ChengdaoZheng, Shengkui