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Jiang Z.,Huazhong University of Science and Technology | Qiu H.,Huazhong University of Science and Technology | Zhao M.,Wuhan Heavy Duty Machine Tool Group Corporation | Zhang S.,Huazhong University of Science and Technology | Gao L.,Huazhong University of Science and Technology
Engineering Computations (Swansea, Wales) | Year: 2015

Purpose-In multidisciplinary design optimization (MDO), if the relationships between design variables and some output parameters, which are important performance constraints, are complex implicit problems, plenty of time should be spent on computationally expensive simulations to identify whether the implicit constraints are satisfied with the given design variables during the optimization iteration process. The purpose of this paper is to propose an ensemble of surrogates-based analytical target cascading (ESATC) method to tackle such MDO engineering design problems with reduced computational cost and high optimization accuracy. Design/methodology/approach-Different surrogate models are constructed based on the sample point sets obtained by Latin hypercube sampling (LHS) method. Then, according to the error metric of each surrogate model, the repeated ensemble of surrogates is constructed to approximate the implicit objective functions and constraints. Under the framework of analytical target cascading (ATC), the MDO problem is decomposed into several optimization subproblems and the function of analysis module of each subproblem is simulated by repeated ensemble of surrogates, working together to find the optimum solution. Findings-The proposed method shows better modeling accuracy and robustness than other individual surrogate model-based ATC method. A numerical benchmark problem and an industrial case study of the structural design of a super heavy vertical lathe machine tool are utilized to demonstrate the accuracy and efficiency of the proposed method. Originality/value-This paper integrates a repeated ensemble method with ATC strategy to construct the ESATC framework which is an effective method to solve MDO problems with implicit constraints and black-box objectives. © Emerald Group Publishing Limited. Source


Wu J.,Huazhong University of Science and Technology | Hao G.,Huazhong University of Science and Technology | Deng C.,Huazhong University of Science and Technology | Zhao M.,Wuhan Heavy Duty Machine Tool Group Corporation
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2015

Aiming at the problems that the occurrence time and evolution process of bearing performance degradation were difficult to be identified, a novel performance degradation analysis and assessment method was proposed based on fuzzy C-means clustering algorithm. A data-driven approach was presented to analyze bearing performance degradation process. A fuzzy C-means clustering algorithm was developed to assess the bearing performance degradation, And the process of bearing performance degradation assessment was given. A case study about a rolling bearing was implemented, and the conclusion was showed that the proposed method could better identify the occurrence time of performance degradation and assess the level of performance degradation. ©, 2015, CIMS. All right reserved. Source


Wu J.,Huazhong University of Science and Technology | Deng C.,Huazhong University of Science and Technology | Xiong Q.-Q.,Huazhong University of Science and Technology | Zhao M.,Wuhan Heavy Duty Machine Tool Group Corporation
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2013

To tackle characteristics of nonlinear and low accuracy for traditional reliability assessment, a novel machine tool reliability assessment method based on Bootstrap and Support Vector Machines (SVM) was proposed. The reliability assessment models for point estimation and confidence interval were respectively set up under the condition of the small sample. A sequence diagram of unified modeling language was adopted to describe the entire process of machine tool reliability assessment. A case was implemented by simulation analysis to validate the method. It suggested that the nonlinear and low accuracy encountered in classic machine tool reliability assessment might be solved by using the proposed method when only small sample was obtained. Source


Deng C.,Huazhong University of Science and Technology | Sun Y.-Z.,Huazhong University of Science and Technology | Li R.,Wuhan Heavy Duty Machine Tool Group Corporation | Wang Y.-H.,Huazhong University of Science and Technology | Xiong Y.,Huazhong University of Science and Technology
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2013

Heavy-duty CNC has the characteristics of diverse fault modes and causes, insufficient fault samples, which makes Health state assessment very difficult Based on multi-capability parameter and multiple observation sequences, a HMM model was constructed which could reflect the performance degradation, and expressed the health state of Heavy-duty CNC clearly. Firstly, in order to solve the problem of parameter initialization, the effects of parameter on accuracy of model were resolved by K-means algorithm, Secondly, since single performance parameter was not sufficient for describing the health state of Heavy-duty CNC, the method further discussed the application of multiple observation sequences in modeling. Finally, the proposed health estimation model was validated by ball-screw of the Heavy-duty CNC and the result demonstrated its effectiveness. Source


Wang S.,Huazhong University of Science and Technology | Chen F.,Huazhong University of Science and Technology | Liu T.,Wuhan Heavy Duty Machine Tool Group Corporation | Gou W.,Qinghai Huading Industries Co.
Huazhong Keji Daxue Xuebao (Ziran Kexue Ban)/Journal of Huazhong University of Science and Technology (Natural Science Edition) | Year: 2015

High-speed spindle works in the state of thermo-mechanical coupling, and the discontinuity caused by structure interfaces has a strong influence on the dynamic behaviour of the spindle. Whereas, the predictions of stiffness, of thermal resistance and especially of the damping characteristics of joints are extremely difficult due to their dependence on many different influences, the desired calculation accuracy of joints has become the bottleneck of high-speed spindle design and performance prediction. Within this paper, based on the fractal theory and the Hertz contact theory, the thermo-mechanical coupling characteristics of high-speed spindle fixed and movable joints were studied, and an approach for the prediction of the physical characterization of joints was established. Resultantly, a new thermo-mechanical modeling of high speed spindle and numerical simulation method with joints characteristics considered were presented, and the validity of presented method has been validated by experimental calibration with a high-speed spindle of machine tool. © 2015, Huazhong University of Science and Technology. All right reserved. Source

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