Key Laboratory of High Efficiency and Clean Mechanical Manufacture

Laboratory of, China

Key Laboratory of High Efficiency and Clean Mechanical Manufacture

Laboratory of, China
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Liu H.,Shandong University | Wang Z.,Shandong University | Wang Z.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Fang S.,Shandong University | Li C.,Shandong University
Mathematical Problems in Engineering | Year: 2017

A constrained low-cost SINS/OD filter aided with magnetometer is proposed in this paper. The filter is designed to provide a land vehicle navigation solution by fusing the measurements of the microelectromechanical systems based inertial measurement unit (MEMS IMU), the magnetometer (MAG), and the velocity measurement from odometer (OD). First, accelerometer and magnetometer integrated algorithm is studied to stabilize the attitude angle. Next, a SINS/OD/MAG integrated navigation system is designed and simulated, using an adaptive Kalman filter (AKF). It is shown that the accuracy of the integrated navigation system will be implemented to some extent. The field-test shows that the azimuth misalignment angle will diminish to less than 1°. Finally, an outliers detection algorithm is studied to estimate the velocity measurement bias of the odometer. The experimental results show the enhancement in restraining observation outliers that improves the precision of the integrated navigation system. © 2017 Huisheng Liu et al.

Gao Q.,Shandong University | Gao Q.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Wang H.,Shandong University | Wang H.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Wu Y.,Hudong Zhonghua Shipbuilding Group Co.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2017

Existing models of variant design process were mostly built at part level, and activity relationship definition was coarsely grained. Design process planning had to traverse all of the possible design activities, which resulted in low design efficiency and bad dynamic adaptation. A dynamic planning method for variant design process based on design structure matrix (DSM) was presented. Firstly, the variant design activity hierarchy model was built, including product level, feature level and parameter level. According to the hierarchy model, the product design activities can be divided into six types. The constraint relationships and their priority values between design activities at each level were defined. Then, the concept of virtual activity was proposed considering that traditional DSM cannot deal with the dynamics of design process. By packaging and decomposition operations of virtual activities, dynamic planning of the design process under complex coupling condition was achieved based on DSM. The design process planning and execution were alternated with each other. With the selection of dynamic design activities, the design process planning was adjusted continuously so as to ensure optimal execution sequence of the design activities. Finally, the method presented was applied to develop the bearing design wizard. Compared with traditional methods, the method presented was easier to adapt to dynamic design process, and it improved process planning efficiency and shortened design time. © 2017, Chinese Society of Agricultural Machinery. All right reserved.

Li H.-K.,Dalian University of Technology | He C.-B.,Dalian University of Technology | Yu G.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Xu F.-J.,Dalian University of Technology
Zhendong Gongcheng Xuebao/Journal of Vibration Engineering | Year: 2017

The impeller is the core component of a centrifugal compressor, and so the realization of the identification of the compressor blade crack fault if of great significance in the industrial production. The abnormal vibration of the blade with cracks will be directly reflected in the fluid pressure pulsation. In practice, however, the abnormal vibration caused by blade cracks are very small, which usually means that it is very difficult to identify the fail frequency since the fault information in the pressure pulsation is too weak. In this paper we firstly deal with the fluid pressure pulsation signals which flow through the fault of impeller bleaching with the sparse underdetermined blind source separation algorithm. Then, the envelope analysis method is applied to the separated signals. Finally, we extract the fault characteristic frequency from the separated signals by the envelope analysis and successfully detect the blade crack fault on the centrifugal compressor impeller. This can be used for long-term health monitoring of the centrifugal compressor impeller. © 2017, Nanjing Univ. of Aeronautics an Astronautics. All right reserved.

Zhang J.,Shandong University | Liu Y.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Liu J.,Shandong University | He T.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Xie Y.,Shandong University of Science and Technology
Vibroengineering Procedia | Year: 2017

To improve dynamic characteristics of synchronous magnetic coupling, this paper mainly analyzed the influence of the installation deviation on the synchronous magnetic couplings dynamic performance used in the horizontal axis wave energy power generation device. Dynamic characteristics equations based on Lagrange equation are built in the paper to analyze the dynamic characteristic of synchronous magnetic coupling. The radial deviation, the angle deviation and the center-of-mass deviation are considered in the equation. The influence of those installation deviations on the synchronous magnetic coupling performance is analyzed based on the mathematical model. The results show that the rise time, the overshoot, the peak time, the adjusting time and the oscillation of the synchronous magnetic coupling are almost not affected by those installation deviations. © JVE INTERNATIONAL LTD.

Jin D.,Shandong Polytechnic University | Liu Z.,Shandong University | Liu Z.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture
International Journal of Advanced Manufacturing Technology | Year: 2013

FGH95 is one kind of powder metallurgy (PM) superalloy which has excellent mechanical properties at high temperature. It has been developed for turbine disc applications to improve aeroengine efficiency under higher operating temperatures. However, this kind of superalloy is very difficult to machine because of its poor thermal diffusivity and work-hardening properties during the machining process. The machining process can lead to damage of the machined surface and subsurface. Thus, the purpose of this paper was to investigate damage of the machined surface and subsurface in hard machining of FGH95 PM superalloy. Orthogonal milling experiments using coated carbide inserts were carried out on a CNC machining center. The machined surface was observed and recorded using an optical microscope, white light interferometer, and scanning electron microscope. Machined surface defects were recorded and analyzed. The effects of cutting speed on machined surface roughness, white layer thickness, plastic deformation, and microhardness were investigated. The research results show that better surface roughness can be generated at higher cutting speeds, while several defects appeared on the FGH95 machined surface. White layer thickness and machined surface microhardness increase with the cutting speed. Also, plastic shear strain in the machined surface layer increases with cutting speed. The depth of plastic deformation decreases with the increase of cutting speed. These investigation results are essential for the evaluation of PM superalloy surface integrity and are significant for the prediction of PM superalloy service life. © 2013 Springer-Verlag London.

Wang B.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Liu Z.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture | Year: 2014

Serrated chip is the frequent chip morphology during high-speed machining of ductile materials, while the mechanism of serrated chip formation still remains some ambiguous aspects. This article presents the investigation of chip morphology from the viewpoint of chip free surface and cross section. Experiments of orthogonal cutting hardened AISI 1045 steel and 7050-T7451 aluminum alloy were carried out. The cutting speed of AISI 1045 steel was varied from 100 to 1000 m/ min, while 7050-T7451 aluminum alloy was machined at the cutting speed of 100-2500 m/min. The feed rate per tooth was varied from 0.025 to 0.20 mm/z corresponding to each experimental cutting speed. The research shows that the microstructure of chip free surface evolves from lamellae to folds and then to dimples. According to the experimental results, a new model of serrated chip formation based on mixed mode of ductile fracture and adiabatic shear is proposed. For the "ductile fracture-adiabatic shear" serrated chips, two distinct zones of ductile fracture and dimples were observed on the slide surface of serrated segments. Through studying chip morphology evolution under different combinations of cutting speed and feed rate, it is found that the degree of chip segmentation has positive correlation with the two parameters. The concept of "critical cutting load" is then proposed to illustrate the conditions under which serrated chips may occur. And the critical cutting load of AISI 1045 steel and 7050-T7451 aluminum alloy is determined by experiments as 0.024 and 0.10 m2/(min z), respectively. © IMechE 2013.

Mi Y.Z.,Shandong University | Zhou Y.Q.,Shandong University | Wang L.,Key Laboratory of High efficiency and Clean Mechanical Manufacture
Advanced Materials Research | Year: 2014

Acceleration signals at the mounts of an excavator cab are collected and analyzed, on the basis of which causes of peak values in the sound pressure level(SPL) at the driver's right ear(DRE) are discussed. A damping material layer made up of chlorobutyl rubber is arranged to the cab's panels by simulations according to results of panel acoustical contribution analysis, which indicates a great decline of the SPL peak values. © (2014) Trans Tech Publications, Switzerland.

Liu R.L.,Shandong University | Liu R.L.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Zhu H.G.,Shandong University
Advanced Materials Research | Year: 2014

With STEP-NC (ISO 14649) being gradually accepted as new standard for programming computerized numerical control (CNC) machine tools, new technologies and computer systems in the design and manufacturing process chain are emerging, and conventional systems are reshaping, to support interoperable and intelligent manufacturing. This paper addresses issues and solutions for the adaptation. In the first place, a strategy for adapting legacy CNC turning machine tools to the emerging standard is presented. In the second place, the new data model is analyzed and a practical way to retrieve and extract manufacturing information from the STEP-NC part program for turning process is presented. In the third place a workable approach to calculating the cutting force and chip load in turning operations is presented based on the mechanistic modeling method. Finally the proposed approach is implemented in a prototype system and tested with an example STEP-NC program for turning, which shows not only the feasibility of the proposed approach for information extraction and process evaluation, but also the possibility of using simple transitional systems to bridge the gap between the sophisticated STEP-NC part program and conventional CNC machines. © (2014) Trans Tech Publications, Switzerland.

Yin J.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Zhang J.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Zhang Y.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture | Wang W.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture
Journal of Applied Polymer Science | Year: 2016

Particulate-filled polymer composites (PFPC) have received a great deal of attention in the field of precision machine tools because of their excellent vibration-alleviating property. However, applications of PFPC in the field of precision machine tools are restricted by its limited mechanical strength. The pores in PFPC are one of the key influences on its mechanical properties, such that the porosity determines the overall mechanical properties of the PFPC directly. In this paper, the relationship between porosity and mechanical properties (compressive strength, flexural strength, elasticity modulus) and damping ratio of PFPC was studied systematically. A strong correlation between the porosity and the mechanical properties and damping ratio of PFPC was found. The results show that the mechanical properties (damping ratio) of PFPC deteriorated (increased) dramatically with increasing porosity. An empirical formula was proposed for the relation between the porosity and the mechanical properties (and damping ratio) of PFPC. © 2016 Wiley Periodicals, Inc.

Lv K.,Shandong University | Huo M.,Shandong University | Li F.,Key Laboratory of High Efficiency and Clean Mechanical Manufacture
Applied Mechanics and Materials | Year: 2013

In order to achieve the precise control of the compressed air foam proportioning on the fire engines, in this paper, the PIC microcontroller and the fuzzy control algorithm are used to design the microcontroller-based foam proportioning hybrid fuzzy control system. Taking into account the system cost and ease, we use the software to implement the fuzzy control of DC motor. The controller learns from the experience of skilled operators, and forms fuzzy control rules, finally we identify a number of important control parameters in this paper. The experimental results show that the fuzzy control system can achieve precise control of the mixing ratio. © (2013) Trans Tech Publications, Switzerland.

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