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The purpose of this paper is to propose a kind of fuzzy adaptive control method to control non‐linear system that has the characteristic of small time delay and fast respond speed.

The paper analyzes the production process and the actual condition of the preheat process of the plating zinc and painting plastic scribbled of double layer welded pipe that has the small time delay and fast respond speed, and also gives the preheat process mathematical model. Fuzzy adaptive control method with hierarchical structure is used which aims at one non‐linear system that has the characteristic of small time delay and fast responds speed. Through the simulation, it proves the mentioned method is effective to control the temperature system for double layers welded pipe in welding process.

Based on the mathematical model proposed about the production process and the actual condition of the preheat process, the fuzzy adaptive control method is effective to control the temperature system for double layers welded pipe in welding process.

The paper proposes fuzzy adaptive control method with hierarchical structure which has the basic fuzzy control grade, adaptive adjust grade, and process state judgment grade.

A very useful method in welding process for double layers welded pipe.

The new mathematical model is proposed about the production process, and the new control method is used in the temperature system for double layers welded pipe in welding process.

The purpose of this paper is to study the real-time change of surface roughness at different small regions of piston rings during running-in process. Meanwhile, the effects of real-time change of the rough surface topography on the lubrication and friction of piston rings are investigated.

An uneven wear model has been developed to research the running-in behavior at the different small regions of piston rings. The model is verified by comparing the simulation results with the experimental results on a reciprocating friction and wear test rig.

This research shows that the wear process of piston ring surface is uneven during running-in. At most time of the operating cycle except the vicinity of top dead center and bottom dead center, the minimum oil film thickness ratio increases while the friction force and power loss decrease after the running-in period.

Through this research, the running-in behavior of piston rings is investigated in detail. The interaction between the running-in and the lubrication and friction of piston rings is understood more deeply.

This paper aims to improve the efficiency and the quality of metal dental prostheses, reporting on the first patient‐fitted titanium (Ti) complete denture base plate fabricated by integrating the technologies of computer‐aided design and computer‐aided manufacture (CAD/CAM) and laser rapid forming (LRF).

To make a complete Ti denture base plate, the traditional lost‐wax‐casting technique is commonly used in dentistry. In order to simplify this labor‐intensive process, a new method combined with LRF was invented. Initially, a maxillary edentulous plaster cast was converted to point cloud data by laser scanning system. Subsequently, point cloud data were reconstructed into a 3D solid digital cast, which is stored in standard triangulation language format. Thereafter the 3D denture base was sliced electronically into a sequence of layers defining the regions of the component and, based on it, the complete Ti denture base plate was built layer‐by‐layer using a laser additive manufacturing technology.

After CAD/CAM/LRF process, the Ti denture base plate was designed and successfully fabricated layer‐by‐layer. After the traditional dental finishing techniques, the complete Ti denture base plate was made and assessed by clinician and patient. The clinical evaluation on quality of fit was judged to be acceptable.

The CAD/CAM/LRF system is a potential candidate to replace the traditional lost‐wax‐casting technique and provides a new platform for the design and manufacturing of custom‐made Ti denture plates and other restorations especially for implant substructure and framework of partial removal of denture.

During running-in, the change in the honed cylinder liner surface alters the performance and efficiency of the piston ring-pack system. The present paper, thus, aims to investigate the surface topography and wear and friction evolution of a cylinder liner surface during the running-in tests on a reciprocating ring–liner tribometer under a mixed lubrication regime. After an initial period of rapid wear termed “running-in wear”, a relatively long-term steady-state surface topography can emerge. A numerical model is developed to predict the frictional performance of a piston ring-pack system at the initial and steady-state stages.

The liner surfaces are produced by slide honing (SH) and plateau honing (PH). The bearing area parameter (Rk family), commonly used in the automotive industry, is used to quantitatively characterize the surface topography change during the running-in process. A wear volume-sensitive surface roughness parameter, Rktot, is used to show the wear evolution.

The experimental results show that a slide-honed surface leads to reduced wear, and it reduces the costly running-in period compared to the plateau-honed surface. The simulation results show that running-in is a beneficial wear process that leads to a reduced friction mean effective pressure at the steady-state.

To simulate the mixed lubrication performance of a ring–liner system with non-Gaussian roughness, a one-dimensional homogenized mixed lubrication model was established. The real surface topography instead of its statistical properties is taken into account.

This study aims at proposing an approach for optimizing the shape of the top piston ring face for minimum friction force using an inverse method. The shape of the top piston ring face determines the amount of oil distribution in the interface of the ring and liner. Therefore, the shape has a significant impact on the tribological performance of this interface.

The shape of the ring face is represented by a polynomial function and is based on the load analysis of the ring. The optimization of the shape was performed using the Sequential Quadratic Programming method. The minimizing of the friction parameter at the interface was considered during the solving process to obtain an optimum ring shape.

The optimized high degree of the shape of the ring face could lead to a reduced friction parameter. The proposed method could be applied for the tribological design and optimization of the piston rings.

There still need effort to investigate the effect of design parameters (e.g. property of lubricant)on the optimization of the ring face.

The subject matter is important and the method has practical value.

The purpose of this paper is to study friction and wear properties of three types of steels against paper-based friction disc, including 65Mn, 20#steel and 30CrAl, so as to obtain the appropriate working conditions for different friction materials in the transmission system.

Based on actual working conditions, pin-on-disc tests are conducted on a universal material tester. The two evaluation indexes, including average friction coefficient and variation coefficient, are introduced to analyze the different friction properties among three types of steel. Furthermore, the temperature-dependent wear pattern and wear depth are subsequently studied.

The results show that 65Mn is more suitable for working under heavy load and low velocity, but 30CrAl and 20#steel are suitable for working under light load and high velocity. Moreover, wear primarily occurs on paper-based material and peaks at about 325.

This research of different materials and friction property for friction pairs is helpful to improve the performance and prolong the service life of transmission systems.

Suitable working conditions of different friction materials are obtained, and the correlation between wear and decomposition in high temperature is verified.