Application of Artificial Intelligence Technology in Decision-Making of Mechanical Manufacturing Process

The traditional mechanical manufacturing process is to transform all raw materials into the final materials and products and directly into the international market all the production process, in this process we involved a lot of problems about decision-making methods, decision-making process is a most basic production technology activity, it is widely exists in the whole social life and each link of enterprise production. This paper studies the decision-making method of mechanical manufacturing process based on artificial intelligence, optimizes the process parameters of plastic integrated mechanical manufacturing process, and compares it with the traditional decision-making method. Finally, the experimental results are obtained that the traditional decision-based method is reduced by more than 10% in size error. But several experiments, the AI decision-making method appeared deviation, the error results are higher than the traditional decision-making method, which may be objective factors, but also reflects the possibility of instability, in the result of deformation. AI-based decision method performance is higher than the traditional decision-making method, reduce the deformation amount by 3.5%

Microstructure Evolution of AlSn20Cu Alloy Prepared by Conventional Casting and Semi Continuous Casting during Rolling and Annealing

AlSn20Cu alloy is currently one of the most widely used bearing materials, and its microstructure is the most important indicator in application. In this paper, AlSn20Cu alloy ingots were prepared by two methods: ordinary casting and semi-continuous casting, and deformation and annealing process of the two ingots were studied. Scanning electron microscope (SEM) and Image Pro Plus software were used to observe and analyze the evolution of the microstructure, and the morphological information such as the average grain size and area fraction of the Sn phase was quantitatively characterized. The effects of casting method, deformation temperature, deformation amount and annealing temperature on the morphology of Sn phase were studied in this paper. Compared with ordinary casting, the cooling rate of semi-continuous casting is higher, so the Sn phase is smaller, the casting defects are less, and the deformability of the alloy is better. The AlSn20Cu alloy prepared by ordinary casting has better deformability at about 140 °C, while the AlSn20Cu alloy prepared by semi-continuous casting can be rolled and deformed at room temperature. When the deformation is greater than 40%, after annealing at 250 °C, the average grain size of the Sn phase in the AlSn20Cu alloy prepared by semi-continuous casting is around one hundred square microns and the area fraction is more than 10%, and the Sn phase morphology is better than ordinary casting alloy under any processing conditions.

Method for Tunnel Displacements Calculation Based on Mobile Tunnel Monitoring System

Efficient, high-precision, and automatic measurement of tunnel structural changes is the key to ensuring the safe operation of subways. Conventional manual, static, and discrete measurements cannot meet the requirements of rapid and full-section detection in subway construction and operation. Mobile laser scanning technology is the primary method for tunnel detection. Herein, we propose a method to calculate shield tunnel displacements of a full cross-section tunnel. The point cloud data, obtained via a mobile tunnel deformation detection system, were fitted, projected, and interpolated to generate an orthophoto image. Combined with the cumulative characteristics of the tunnel gray gradient, the longitudinal ring seam of the tunnel was identified, while the Canny algorithm and Hough line detection algorithm identified the transverse seam. The symmetrical vertical foot method and cross-section superposition analysis were used to calculate the circumferential and radial displacements, respectively. The proposed displacement calculation method achieves automatic recognition of a ring seam, reduces human–computer interaction, and is fast, intelligent, and accurate. Furthermore, the description of the tunnel deformation location and deformation amount is more quantitative and specific. These results confirm the significance of shield tunnel displacement monitoring based on mobile monitoring systems in tunnel disease monitoring.

Investigation of Nonlinear Creep Behaviour of Millettia Laurentii Wood Through Zener Fractional Rheological model

Nowadays one of the principal difficulties that wood structural development and construction have to face is wood creep. Nevertheless, the secret to master and solve the creep deformation of wood relies on a sensible and exact rheological model for numerical analysis. In this research work our goal is to study the nonlinear creep behaviour of the Cameroonian wood species Millettia Laurentii known as Wengé wood through fractional calculus approach. So, we have conducted a nonlinear creep constitutive model of Millettia Laurentii wood, that is the Zener fractional rheological model, and the parameters of this model have been determined. We have studied the influence of stress level σ and fractional order n on the Millettia Laurentii wood creep process by a sensitivity analysis of the model parameters. The outcomes of this sensitivity analysis are of paramount importance because they can be used in reality to inspect the creep process and deformation amount of Millettia Laurentii wood in practical engineering. Moreover, guidance for the secure construction of Millettia Laurentii wood engineering can be given by the means of the findings of this research.

Characterizing the Deep Pumping-induced Subsidence Against Metro Tunnel Using Vertically Distributed Fiber-Optic Sensing

Continuous pumping of groundwater will induce uneven ground settlement, which may adversely affect the nearby metro tunnels. In this paper, taking Nantong Metro Line 1 crossing Nantong Port Water Plant as an example, the surface level measurement and subsurface deformation monitoring using vertically distributed fiber-optic sensing are implemented to acquire the surface and subsurface settlement of emergency water supply conditions. The fiber optic cable vertically buried in the constant-temperature layer is used to measure the subsurface strain field and deduce the deformation amount of each stratum. The monitoring results show that, during the pumping, the deformation of the aquifer and ground surface is linearly compressed with time; after the pumping, the ground surface continues to settle linearly at a slower rate for about 50 days, followed by a slow linear rebound, and the aquifer is logarithmically rebounded. In addition, deep pumping causes the deformation of the aquifers to be much greater than the surface settlement; the surface settlement lags behind the settlement of the aquifer by 1 to 2 months; the surface rebound recovery also exhibits a similar delay. Fitting models were derived to predict the maximum settlement and curvature radius of the site, which indicates that the adverse effects against the metro tunnel are not negligible once the continuous pumping exceeds 15 days. Those insights can be referred by the practitioners for the control of urban subsidence.

Study on the Loess Immersion Test of Metro Line 2 in Xi’an, Shaanxi Province, China

With the implementation of China’s western development and “One Belt, One Road” initiative, there are more and more projects in the collapsibility loess area, and the collapsibility loess problem encountered in the construction is becoming more and more prominent. In this paper, the collapsibility loess of the south extension section of Xi’an Metro Line 2 is investigated, and its collapsibility characteristics are studied through a large-scale site immersion test. The test site was a 15 m diameter circular test pit, which took 35 days for water injection and 60 days for observation after water stopped. The test results showed that the maximum self-weight collapsibility of the soil layer in the test pit is 32 mm, and the deformation amount is 10.05 mm in Q3 and 9.55 mm in Q2. The maximum deformation amount of 32 mm is less than 70 mm in the shallow marker; it may be caused by the paleosol layer as a bridge to provide a support to the overlying soil layer. The shape of the sphere of influence after immersion resembles a trumpet, slightly protruding outwards from the paleosol. The scope of influence between the infiltrated and saturated zones gradually increases with depth, and the saturated zone is generally smaller than the infiltrated zone. The research results of this paper can provide technical support and reference for the construction of Xi’an Metro Line 2 and other related projects in the region.

Research and Experimental Verification on Coupling Mechanical Characteristics of Surrounding Rock of Hydraulic Support Group in Comprehensive Working Face

The hydraulic support group and the surrounding rock in fully mechanized mining faces often do not exist in isolation; rather, they compose in a mutually coupled system. Research on the mechanical characteristics of roofs under the support of group supports can lay a foundation for the determination of the ideal support strength of group support equipment. This paper establishes a coupled mechanical model of the surrounding rock of hydraulic support groups in a fully mechanized mining face. Through variable parameter calculations, the influence of different roof elastic moduli, mining heights, working face lengths, end face distances, support stiffnesses, coal wall stiffnesses and direct roof thicknesses on roof deformation is analyzed, and the corresponding ideal support strength of a hydraulic support is given. The results show that: the deformation of the roof and the ideal support strength of the hydraulic support group decrease as the elastic modulus of the roof increase; the deformation amount of the roof and the ideal support strength of the hydraulic support group increase as the mining height increases; the deformation amount of the roof and the ideal support strength of the hydraulic support group increase as the working face length increases; the deformation amount of the roof and the hydraulic support group also increase. The results also show that the ideal support strength of the support group decreases as the face distance of the top beam end increases; the deformation of the roof decreases significantly as the equivalent stiffness of the hydraulic support group increases, but the ideal support strength of the hydraulic support group increases significantly; the deformation amount of the roof and the ideal support strength of the hydraulic support group decrease significantly as the equivalent stiffness of the coal wall increases; and the deformation amount of the roof and the hydraulic support are significantly reduced. The ideal support strength of the support group decreases as the thickness of the direct roof increases, especially in the middle of the working face. Finally, by setting the ideal support strength in the 12401 working face of the Shangwan Coal Mine of Shendong Group, the accuracy of the calculation results is verified by the multisensor measurement method. The research results provide theoretical support for the development of coal resources for deep mining and intelligent directions on Earth.

Study on the Mechanical Behavior of Double Primary Support of Soft Rock Tunnel under High Ground Stresses and Large Deformation

Double primary support structures could effectively solve the problem of large deformation of surrounding rock for soft rock tunnels. However, the mechanical behavior of this new support structure is still incomplete, and the design method should be revised. Based on the theory of energy conversion, this paper analyzes the support characteristic curve of double primary support and puts forward the dynamic design method of double primary support. Considering that the secondary lining can be set after monitoring the deformation amount and deformation rate of the first primary support, its support parameters can be dynamically adjusted according to the actual situation. By applying the double primary support design method in the Maoxian tunnel of Chenglan Railway, the field monitoring results show that the double primary support has a significant effect on the energy release of surrounding rocks, greatly reducing the load acting on the secondary lining and ensuring the safety and reliability of the tunnel structure.

Modeling and simulation on speed prediction of bypass pipeline inspection gauge in medium of water and crude oil

Bypass pipeline inspection gauges have the advantages of low cost and bringing no consumption in transportation efficiency and have been widely used in pipe cleaning, inspecting, and maintaining operations. The moving speed of bypass pipeline inspection gauges will seriously affect the results of the operations, so there are strict requirements on the moving speed of bypass pipeline inspection gauges. Because the moving speed of pipeline inspection gauge is difficult to measure or control in real time, it is important to predict it. This paper studies the influencing factors and their impact methods of pipeline inspection gauges’ motion. Through the combination of computational fluid dynamics simulation and friction mathematical model, the relationship between the value of the bypass hole diameter and the pipeline inspection gauges’ moving speed was studied. Under the selected research conditions, when the diameter of the bypass hole is increased from 0.1 to 0.5 m, the moving speed of pipeline inspection gauge in water and crude oil is, respectively, decreased from 2.779 to 0.589 m/s and from 2.777 to 0.373 m/s, and the relationship between them can be approximately described by a function. Based on this principle, the moving speed of pipeline inspection gauge can be predicted mathematically. The experiments also indicate that the density and dynamic viscosity of the transport medium and the deformation amount of the bypass pipeline inspection gauge sealing disk will affect the movement state of pipeline inspection gauge in the pipeline. This research has guiding significance for the design of the pipeline inspection gauges’ structure size, which is beneficial to the pipeline robot to better meet the needs of cleaning, inspecting, and maintaining operations, and has reference value for related researches.