The infrastructure construction process cannot be separated from construction machinery; it will inevitably produce wear and tear in the work. The level of wear and tear is severe and could cause mechanical accidents. There are safety hazards involved with wear and tear; thus, the study of the lubrication systems of construction machinery is crucial. This paper addresses the problems with the intelligent lubrication systems of construction machinery and establishes a performance evaluation index system for the intelligent lubrication systems of construction machinery by analyzing and selecting appropriate evaluation indexes. Based on the built evaluation system, a performance evaluation model was established based on the hierarchical analysis (analytic hierarchy process, AHP)–entropy weight method and a topological object element model. The feasibility of the model was tested using the example of an off-road mining dump truck. This model analyzes the performance strengths and weaknesses of smart lubrication systems and suggests improvement measures and recommendations for weak links. It also provides a reference for analyzing the performance of smart lubrication systems for other mechanical devices.

Urban rail transit system planning is significant for alleviating traffic congestion and optimizing spatial resource allocation in cities with scarce land resources. However, the long period of rail transit construction, large-scale investment, and its planning involve a variety of factors, which require scientific and reasonable evaluation methods to ensure that its construction can realize the expected economic and social benefits. To solve this problem, this study first establishes an appropriate evaluation system by selecting suitable evaluation indicators. Then, the comprehensive assignment method combining the ordinal relationship method (G1 method) and the improved entropy weight method is applied to assign weights to the indicators in the evaluation system, and the correlation degree is calculated by combining with the matter-element model for evaluating the planning scheme of the urban rail transit system. Finally, the urban rail transit system planning scheme of Zhengzhou City is verified by example. The results show that the proposed method can balance the practical significance and dynamics of the evaluation indices, evaluate the importance of each index more objectively, and provide methodological support for dynamic decision-making in rail transportation planning in the context of a smart city, which is of guiding significance for the sustainable development of the city.

Friction wear is inevitable in roller bearings at high speeds, under heavy loads and vibration, and in other operating conditions. The use of grease can significantly reduce frictional wear. Sulfur–phosphorus additives have excellent anti-wear properties, oxidation resistance, and stability under high load and high-speed conditions. Their application in roller bearings enhances the performance of the grease, thus ensuring the normal operation of roller bearings. This study focuses on the effect of interaction between sulfur–phosphorus additives. Using a friction and wear tester and a rotational rheometer, the original roller bearing grease Fuchs 585k plus was used as the original grease, and the original grease was blended with MoS₂, MoS₂+TBP, and MoS₂+T321, respectively, to comparatively analyze the effect of sulfur–phosphorus additives and their interaction effect on the tribological and rheological properties of the roller bearing grease. The results show that the addition of all the above three additives can improve the anti-wear performance and anti-shear performance of roller bearing grease. Among them, the most significant optimization effect is MoS₂+T321, followed by MoS₂, and finally MoS₂+TBP. This result provides a new idea for the performance enhancement and formulation optimization of roller bearing grease.

In the field of high-end equipment, the synergistic effect of friction-reducing agents plays an important role in the performance study of gel grease. Exploring its tribological and rheological properties can not only significantly reduce the coefficient of friction of mechanical components and enhance its viscosity at high temperatures but also effectively reduce energy consumption, thus improving the service life of high-end equipment. In this study, Schaeffler Load 460 gel grease was mixed with polysiloxane viscosity modifier (PV611) and molybdenum dialkyl dithiocarbamate (RFM3000) according to (3:1, 1:1, and 1:3), and its tribological properties and rheological properties were investigated by the MRS-10G friction and wear tester, MCR302 rotational rheometer, and crossover test. Comparative analyses of tribological and rheological properties were carried out. The results showed that the average coefficient of friction of Schaeffler Load 460 grease was reduced by 57.2%, 60%, and 71.9%, respectively, with the addition of two different ratios of friction reducers; the average diameter of abrasive spots was reduced by 44.5%, 55.4%, and 61.3%; and the shear stress and viscosity were increased by 117.94 Pa and 1295.02 mPa∙s, respectively, compared with that of the original grease, which is a good example for the lubrication of gel grease in the high-end equipment industry. This study provides a new direction and idea for the lubrication research of gel grease in the high-end equipment industry.