Mechanical Engineering College

Jiazhuang, China

Mechanical Engineering College

Jiazhuang, China
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Tang J.,Chongqing University | Lu Y.,Chongqing University | Ge Z.,Chongqing University | Xia B.,Chongqing University | And 2 more authors.
International Journal of Mining Science and Technology | Year: 2014

Based on the technologies of traditionally mechanical drilling and water jet, we propose a new method of abrasive water jet in combination with rock drilling, and establish a combined rock drilling system for the gas pre-drainage. This study chose the common sandstone and silicon limestone as the rock sample. A series of experiments were completed in the case of dry drilling, existing technology drilling, combined drilling with high pressure water jet and combined drilling with abrasive water jet, respectively. The drilling efficiency and performance were contrasted and analyzed in detail. The results indicate that it is better to choose the method of combined drilling with the high-pressure water jet for soft rocks. The method of combined drilling with abrasive water jet is feasible for the hard rock drilling and has higher drilling efficiency and performance. In this paper, compared with the existing technology, the drilling depth has increased by about 65%, the axial force and torque have reduced by about 14% and 17%, respectively, and the drill wear reduces obviously in the same conditions. © 2014 Published by Elsevier B.V.

Chen H.,Mechanical Engineering College | Han M.,Hebei University of Science and Technology
Food Research International | Year: 2011

The effects of microbial transglutaminase (MTG) on heat-induced gelation of pork myofibrillar proteins (PMP) structural changes, textural properties were studied by Raman spectroscopy and texture profile analysis (TPA), respectively. And the relationships between the structural changes and textural characteristics were estimated by principal component analysis (PCA). Changes in the Raman spectra were interpreted as the occurrence of secondary structural changes in myofibrillar proteins with MTG added. Modifications in the amide I (1600-1700cm-1) regions indicated a significant (p<0.05) decrease in α-helix content, accompanied by a significant (p<0.05) increase in β-sheets, β-turns and random coil content due to the addition of the enzyme. Obvious texture property changes were also determined by TPA. All these changes showed a strong, irreversible heat-induced gel formed due to the addition of MTG. The application of a dimensionality reducing technique such as PCA proved to be useful to determine the most influential properties of heat-induced gel. Significant (p<0.05) correlations were found between these structural changes and the textural characteristics (hardness) in PMP system with the addition of MTG by PCA. The hardness was related positively to fraction of β-sheet, β-turns and random coil, and negatively to normalized intensity of 760cm-1 and fraction of α-helix. The samples are closely grouped in a cluster defined by level of MTG. © 2011 Elsevier Ltd.

Li B.,Mechanical Engineering College | Zhang P.-L.,Mechanical Engineering College | Liu D.-S.,Mechanical Engineering College | Mi S.-S.,Mechanical Engineering College | And 2 more authors.
Journal of Sound and Vibration | Year: 2011

This paper presents a novel feature extraction scheme for roller bearing fault diagnosis utilizing generalized S transform and two-dimensional non-negative matrix factorization (2DNMF). The generalized S transform, which can make up the poor energy concentration of the standard S transform, is introduced to generate the timefrequency representation (TFR). Experiment results on simulated signal and vibration signals measured from rolling element bearings have revealed that the generalized S transform can obtain a more satisfactory TFR than other similar techniques. Furthermore, a new technique called two-dimensional non-negative matrix factorization (2DNMF), which can reduce the computation cost and preserve more structure information hiding in original 2D matrices compared to the NMF, is developed to extract more informative features from the timefrequency matrixes for accurate fault classification. Experimental results on bearing faults classification have demonstrated that the proposed feature extraction scheme has an advantage over other similar feature extraction approaches. © 2010 Elsevier Ltd All rights reserved.

Li B.,Mechanical Engineering College | Zhang P.-L.,Mechanical Engineering College | Tian H.,Mechanical Engineering College | Mi S.-S.,Mechanical Engineering College | And 2 more authors.
Expert Systems with Applications | Year: 2011

A novel feature extraction and selection scheme was proposed for hybrid fault diagnosis of gearbox based on S transform, non-negative matrix factorization (NMF), mutual information and multi-objective evolutionary algorithms. Time-frequency distributions of vibration signals, acquired from gearbox with different fault states, were obtained by S transform. Then non-negative matrix factorization (NMF) was employed to extract features from the time-frequency representations. Furthermore, a two stage feature selection approach combining filter and wrapper techniques based on mutual information and non-dominated sorting genetic algorithms II (NSGA-II) was presented to get a more compact feature subset for accurate classification of hybrid faults of gearbox. Eight fault states, including gear defects, bearing defects and combination of gear and bearing defects, were simulated on a single-stage gearbox to evaluated the proposed feature extraction and selection scheme. Four different classifiers were employed to incorporate with the presented techniques for classification. Performances of four classifiers with different feature subsets were compared. Results of the experiments have revealed that the proposed feature extraction and selection scheme demonstrate to be an effective and efficient tool for hybrid fault diagnosis of gearbox. © 2011 Published by Elsevier Ltd.

Liu J.K.,Mechanical Engineering College | Qi X.L.,Mechanical Engineering College
Key Engineering Materials | Year: 2013

UV-LIGA technics which used in high aspect ratio micro-structure fabrication has been developed quickly currently, but there still exist many technical problems which may affect the reliability of production, especially in lithography and electroform process. According to analyzing the technical process of bi-layer micro-gear, the reliability problems have been studied from two aspects, including deep lithography and micro electroform. In the deep lithography technology, the adhesive property between SU-8 photoresist and substrate and the non-uniform thickness and bubble problems of SU-8 photoresist layer have been presented. In the micro electroform aspect, problems include non-uniformity, air holes, and adhesive property of electroformed layer. Aimed at these problems, the resolvents have been put forward and validated, which improve the reliability of technics and possess fine effect. © (2013) Trans Tech Publications, Switzerland.

Yao A.,Mechanical Engineering College | Chen Z.L.,Mechanical Engineering College
Applied Mechanics and Materials | Year: 2014

Although turbo equalization has superior performance, the data processing delay produced by large iterations has become its major drawback for real-time situations. Based on the MMSE criterion, the normal-probability-plot(NPP) of linear equalizer's extrinsic information is studied in this paper, with the conclusion of the extrinsic information's approximate Gaussian distribution obtained. In various conditions, the iterative number can be controlled dynamically based on the extrinsic information statistics. The simulation results approves that the technique is able to make delay dwindle largely with small performance degradation. © (2014) Trans Tech Publications, Switzerland.

Gu Z.Y.,Mechanical Engineering College | Li X.M.,Mechanical Engineering College
Applied Mechanics and Materials | Year: 2014

In the assessment subsystem of the UAV health system, the analytic hierarchy process method is used to build up a UAV performance assessment model, and to analyze and determine each factor and subordinate degree affecting UAV system performance or conditions. For the UAV monitoring and inspection data that are quantitative, the data are assessed and scored by the fuzzy AHP method, while for the extent of the data that are non-quantitative, the data will be directly assessed and scored according to the expert system. On the basis of comprehensive analysis and calculation, the scores of safety, durability and serviceability of each section of the UAV can be achieved and the weighted factor method is then used to finalize the grades of the health conditions of the UAV. With all methods mentioned above, the real-time assessment of the health conditions of the UAV is realized and scientific bases of decision-making for maintenance and management of the UAV are thus provided. © (2014) Trans Tech Publications, Switzerland.

Zaifei S.,Mechanical Engineering College | Chunping W.,Mechanical Engineering College
Proceedings - 2014 6th International Conference on Computational Intelligence and Communication Networks, CICN 2014 | Year: 2014

Projectile-Deviation measurement is a key part of shooting calibration of anti-Aircraft artillery systems. In recent years, as the imaging and computer processing speed improved significantly, it makes real-time analysis and getting the deviation from projectile-shooting scene possible. This paper makes a deep research on projectile-deviation measurement using image processing technology, combined with the small target detection algorithm, discusses target detection approach of projectile, and small target detection algorithm is given the main features and trends, research in this field has a certain significance. © 2014 IEEE.

Sun D.Y.,Mechanical engineering College
Applied Mechanics and Materials | Year: 2014

connecting rod parts except under larger dynamic load in the institutions, it is also connected with other parts, movement and direction, therefore, the part of the connecting rod connected with other parts on the machining accuracy is crucial. In this paper, analysis and study connecting rod machining process, through the improvement plan, ensure the accuracy of the important parts of the connecting rod parts and the connecting rod production and processing efficiency. © (2014) Trans Tech Publications, Switzerland.

Zhao Z.,Mechanical Engineering College | Wang M.,Mechanical Engineering College | Zhang L.,Mechanical Engineering College
Key Engineering Materials | Year: 2016

Based on liquid fusion and atomic interdiffusion of TiB2-based ceramic and 42CrMo steel, the ceramic-metal laminated composites with interfacial 3D-network span-scale graded microstructures were achieved by combustion synthesis in high gravity field. The presence of respective atomic concentration gradient of Ti, B, C, Fe and the others between the ceramic and the steel reasoned for continuously-graded interfacial microstructure in which the TiB2 and TiC phases transform sub-micrometer, micro-nanometer grains from the micrometer ones. The Fe-based liquid flow from the ceramic to the steel substrate resulted in the 3D-network distribution of Fe-based alloy phases from the ceramic to the steel substrate. Hence, interfacial shear fracture presented the mixed mode consisting of intercrystalline fracture along fine TiB2 platelets and ductile fracture in Fe-based alloy phases, presenting interfacial shear strength 415 ± 25 MPa of the laminated composite. © 2016 Trans Tech Publications, Switzerland.

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