Most ReadIn order to explore the safety threat of slope deformation to transmission lines, taking the transmission tower-line system as the research object, the overall finite element model of the tower-line system considering soil-structure interaction (SSI) effect is established, and the rationality of the numerical analysis model is verified based on the field measured data. On this basis, considering the relationship between the slope deformation area and the spatial position of the tower and the influence of the slope deformation angle, the response law of the stress characteristics of the tower-line system to the slope deformation is explored. The results show that when the towers are located above, below and inside the slope deformation body respectively, the failure mode and deformation resistance of the upper tower line system are significantly different. And with the increase of slope deformation angle, compared with horizontal slope deformation, the anti-deformation ability of tower-line system will decrease by 25%-50%. When the tower is located outside the slope deformation body, the anti-deformation ability of tower-line system will decrease most seriously, with the decrease range of 33%-50%.
To thoroughly explore the extensive applications and prospects of knowledge graphs in the domain of intelligent manufacturing, aiming to support the sustained development of the manufacturing industry, the domain of intelligent manufacturing has been categorized into four dimensions: vertical industry applications, manufacturing process applications, domain graph construction technology, and intelligent services. Through this study, the significance of knowledge graphs in driving the evolution of intelligent manufacturing is reviewed. Furthermore, a framework for an intelligent manufacturing knowledge graph, rooted in manufacturing domain knowledge data, is proposed. This framework encompasses three key modules: manufacturing domain data, graph construction, and intelligent services, providing theoretical support for the continuous upgrading of intelligent manufacturing. Research findings emphasize the crucial role of knowledge graphs in advancing the intelligence of the manufacturing industry and the broad potential of knowledge graphs in the field of intelligent manufacturing. Additionally, an outlook on future research directions for knowledge graphs in the domain of intelligent manufacturing is suggested, with a focus on exploring the integration of domain graphs with next-generation artificial intelligence technologies to propel the continuous innovation and intelligent evolution of manufacturing.
A theoretical model of stress distribution and contact width is established by Hertz contact theory. The reaction of roller under specific load is analyzed. The results shows that linear profile have significant edge contact stress concentration, which increases with the increase of load. The roller with logarithmic profile can solve the stress concentration, but it can't completely eliminate it. Under the same load, with the increase of the bias factor, the maximum contact stress of the roller decreases sharply at first and then increases slowly. The position where the maximum contact stress occurs shifts from both ends of the roller to the middle of the roller. The profile design of roller with logarithmic type can take a value between 1.0 and 2.5 for the bias factor based on working conditions, roller size and load conditions. The value of bias factor is adaptive to tilt error and the impact of tilt error on contact stress can be reduced by setting a reasonable value.
During the operation of an air cushion belt conveyor, factors such as fan air volume, number of air holes, and film thickness have a significant impact on the flow field characteristics and bearing capacity of the air cushion. By establishing a simulation model for the air cushion flow field, analyze the changes in air cushion pressure under different working conditions. Based on experimental comparison and analysis, the variation law of air cushion pressure under different air volume and number of air holes, as well as the variation of air film thickness and air film pressure under different air volume were analyzed. The results show that as the air volume increases, the film pressure gradually increases, and the film thickness changes from 5% to 30%. As the number of pores increases, the pressure gradient of the air cushion changes faster and exhibits a parabolic distribution, and the degree of change in air film thickness decreases. The experimental and simulation results show that the changes in the air cushion flow field are consistent, and the fan air volume is 15-20 m3/m, the optimal value K1 for the stability of the air cushion flow field is 1.31, and the optimal working condition is 5 exhaust holes, which meets the requirements of actual operating conditions.
Aiming at the problem of motor failure caused by complex factors interacting and interfering during the operation of pure electric mining trucks, a method based on principal component analysis (PCA) and random forest (RF) is proposed for predictive diagnosis. A dataset is constructed based on the actual collected motor failures of electric mining trucks, and the eigenvalue extraction and dimensionality reduction of the failure data are carried out using principal component analysis to reduce the dimensional redundancy of the data; the random forest prediction model is used to train and test the dimensionality-reduced data, and to predict the motor failure categories. The results show that the accuracy of motor fault type diagnosis using PCA-RF method reaches more than 97%, which is significantly improved compared with the accuracy of the method without dimensionality reduction processing. The accuracy of the above method for motor fault diagnosis of electric mining trucks is confirmed.
Middle outrigger is the main support leg of tunnel erecting machine, and hydraulic system plays an important role in the erection process of prefabricated utility tunnel sections. To solve the problems of slow action and low positioning accuracy of hydraulic cylinder of middle outrigger, the hydraulic system of tunnel erecting machine is optimized through on-site experiments and AMESim simulation analysis. According to the erection process and hydraulic system principle of tunnel erecting machine, a preliminary analysis and on-site measurements of original middle outrigger hydraulic system are conducted, and an optimized system scheme applying high-frequency response proportional valve and accumulator is proposed. Then, the reasonable accumulator working parameters of optimized hydraulic system are explored, and the high-frequency response proportional valve control strategy based on feedforward compensation is studied. Finally, the optimized hydraulic system is simulated and compared with measurement data. The results show that the combination of high-frequency response proportional valve and accumulator can significantly improve the response characteristics and position control accuracy of hydraulic system. The hydraulic cylinder displacement of optimized system is increased by 82.2% within 0.5 s of system startup, and the maximum hoisting positioning error is ±2.0 mm, which can meet the erection and installation requirements of utility tunnels.
In recent years, intelligent control technology has occupied an increasingly significant position in the field of modern engineering research. With the rise of artificial intelligence technology, it provides more possibilities for construction machinery to realize intelligent control. In the development process of intelligent technology, the control accuracy of construction machinery system is improved, industrial production is more reliable and safe, and the production efficiency of enterprises is improved. This paper starts from the content of intelligent control technology, introduces various intelligent control technology theories and methods, and discusses the application of intelligent control technology in various construction machinery according to intelligent technology methods. At the same time, the key problems and technical system of future construction machinery under intelligent control are analyzed and studied, which provides reference for the intelligent development of construction machinery control technology.
In order to improve the operating efficiency of excavator hydraulic system, a pump-driven valve-controlled load sensing system was designed. Pressure sensors are installed at the inlet and outlet of the multi-way valve respectively to perform real-time pressure feedback instead of the pressure compensation valve of the load sensitive system to achieve pressure compensation, and dynamically adjust the position of the main valve core and the swash plate swing angle of the electro-hydraulic proportional pump to drive the action of the hydraulic cylinder. The valve-controlled cylinder system in the pump drive valve control system is analyzed theoretically and the mathematical model is established. The experimental platform is designed with proportional valve test bench, BODAS controller and other electronic control and acquisition components, and the principle test of pump drive valve control is carried out, which verifies the correctness of the simulation model and pump drive valve control principle. The results show that when the system is in the pump drive valve control program, the output flow rate changes abruptly with the load change of step rise under different pressure differences. With the continuous increase of load pressure, the flow mutation becomes larger and larger, and the error between the output flow and the set flow also increases.
Aiming at the vibration response of vehicle-mounted precision equipment in a motorized environment, a new type of combined vibration isolator based on spring and rubber structure is proposed under the constraints of known equipment characteristics and vibration isolation performance requirements, and then a three-dimensional vibration isolation system of the vehicle-mounted precision equipment is designed by connecting the vibration isolators in parallel. In this paper, a three-dimensional model of the vibration isolation system is established, and the vibration isolation performance of the system in transverse, longitudinal and vertical directions is analyzed based on ABAQUS, and the three-direction rms acceleration attenuation rates are 0.82, 0.94, 0.93, respectively; meanwhile, the random vibration test results show that the three-direction rms acceleration attenuation rates are 0.88, 0.75, 0.87, respectively, which is within 10% of the simulation result, verifying that the three-direction rms acceleration attenuation rates are within 10% of the simulation results. are within 10%, which verifies the accuracy of the simulation results and meets the demand for vibration reduction of vehicle-mounted precision equipment.
Lightweight design is an effective way to improve the economic and environmental protection of static pile driver, as the key component of the static pile driver, the combined fixture is important for its lightweight design. To realize the combined fixture structure safety and lightweight design goal, a three-dimensional model is established by using solid works, and ANSYS Workbench is used to analyze and evaluate the equivalent stress of the whole structure and main components under the condition of pile pressing. Based on the results of analysis and evaluation, the topology optimization method of superposition replacement is adopted to carry out the structural optimization design, while meeting the needs of safety and engineering practice, its total quality is reduced by about 30%, and the economic and environmental benefits are obvious.