For the purpose of providing the assessment criteria of the maintainability qualitative requirements during the design and development phase, the principle and the approach to establish the maintainability qualitative evaluation indicator system was discussed based on GJB368B-2009  General requirement for material maintainability program. Four maintainability qualitative evaluation indicators were extracted from the maintainability qualitative attributes describing all of the maintainability qualitative requirements which were "simplicity and easiness of maintenance", "quickness of maintenance", "safety of maintenance" and "economy of maintenance". The process was proposed to construct the maintainability qualitative evaluation indexes, which was a cycle from "inquiring" to "information analyzing", to "evaluation indexes establishing", to "evaluation indexes demonstrating", and to "evaluation indexes classifying and decomposing".

The application of biological knowledge in product design is the core of bionics. But the traditional method lacks of effective support for systematic utilizing biological knowledge in product design process. The efficiency of the bionic design is very low for the lack of effective analysis method for complex biological information. To settle this problem, the research on biological coupling mechanism was analyzed and a system modeling method based on symbols was proposed to describe and analysis function features and system composition and could be applied in the modeling process for product function features and product composition. Modeling examples in biological system and product technological system were used to verify the practicability and superiority of proposed modeling method.

In the era of knowledge economy leading the development of the society, patent design around for the group of core patents becomes a strategic to help business against competitors and keep competitive in the market. A method to confirm the scope of group of core patents was described. Related patents were found by selecting patent database and making patent retrieval strategy and selecting strategy. Then the group of core patents that needed to be avoided was analyzed using forward citation and the system structure trees and function trees of the group of every patent were established. Module\|function table was built according to relationship of components and their functions, then the scope of patent design around was determined via components of the modules in the table. Lastly, using plug as an example, the scope of group of core patents was found out to assess the superiority of the proposed method.

To study the design change process of adaptable-function machine and its relevant design methodology, the mapping relationship between function and structure in the process of design change on mechanical products were investigated from the perspective of conceptual design based on function-structure mapping model. Three constraint rules of design change were proposed, including the mapping relationship, the constitute relationship and the bidirectional constraint relationship. The associations of functions were analyzed by means of function abstraction in engineering design, by which the product structure was decomposed into changing structure and sharing structure, and the design change could be realized by recombination of the two kinds of structures. Based on these, the design change flowchart and five fundamental steps for realization of design change were proposed, together with a design change execution figure. Finally, a case study of redesigning the numerically control of CA6140 machine was provided to validate the feasibility of the proposed methodology, by using the execution figure of design change.

The degradation of combined rotor, the core parts of the gas turbine, decreases the performance of gas turbine in a large extent. In view of this, it is particularly important to research the performance degradation of the combined rotor. The performance degradation characteristics of combined rotor were discussed, from the perspective view of performance degradation caused by rod crack. The finite element model of the combined rotor was established. The crack extension rate of the rod was gotten by using the finite element model. Then, the measurement of performance degradation which was caused by micro cracks was put forward, and the assessment of performance degradation was completed as well. The results showed that the micro crack extension rate got faster when the size of crack increased; the microcrack tie rod with different distribution form did make a difference to the degradation of the combined rotor as the adjacent microcrack tie rods led to the fastest degradation rate and the 180° distributed microcrack tie rods led to the slowest degradation rate.

In order to reasonably determine the checking cycle of the tension leveler for copper belt, simultaneously improve its productivity and its straightening precision,   the system failure mode were converted into a corresponding stochastic Petri nets and a stochastic Petri nets model of tension leveler failure mode was made according to the maintenance data of a company's  tension leveler for copper belt within nine months. Based on Markov process, the transient  probability for the stochastic Petri nets was worked out and the  steady-state  probability for tension leveler failure modes was got. The availability of tension leveler with different checking cycles was  calculated by analyzing the OR gate corresponded stochastic Petri net model. The reasonable checking cycle was determined  by comprehensively considering the availability and economic efficiency, which provided the basis for long-term cycle running of tension leveler.

The thermal errors, fracture and fatigue will be occurred when micromanipulation stage are woking in environment with temperature changing. In order to improve the accuracy of a micromanipulation stage based on straight-beam flexure hinges, the finite element method was applied to build the thermal response model of the stage considering temperature effect, and the thermal error and stress was analyzed according to the proposed model. Euler-Bernoulli beam was adopted to simulate the mechanical behavior of the straight-beam flexure hinge and links. The mechanical equations of the micromanipulation stage was obtained by using the principle of minimum potential energy. The transfer function between the temperature change and thermal error, thermal stress was derived by using modal truncation technique. A typical bridge\|type micromanipulation stage was used as a example in order to analyze the effects of temperature change on the performance of the stage. The analytical results showed that the thermal error sensitivity to the change of temperature was 0.192 μm/℃, and the change of temperature would produce large static thermal error; the thermal error could be reduced by choosing rational structure parameters. The thermal vibration and stress was 0-0.21 μm and 11.6 MPa, respectively, with a unit change on temperature. Large thermal vibration and stress would be occurred under dynamic thermal loads. In a word, the temperature effects on the micromanipulation stage cannot be ignored, optimization design and the thermal error compensation strategy are needed to reduce the influence.

Quasi static model of high-speed angular contact ball bearing provides an effective analysis mean for determing the internal load distribution and a foundation for dynamic analysis. According to this model, an example of high-speed angular contact ball bearing under axial load was calculated and the change rules of contact force between rolling ball and raceway under different speed and preload were obtained. The calculation results showed that the contact force between rolling ball and the outer raceway increased linearly with the growth of axial preload in the low speed range. And as the rotation rate increased, the contact force exhibited a non-linear variation by trend of decreasing first and increasing later. A detailed analysis of this variation was carried on, and the dual constraints for the determination of the best preload of high-speed angular contact ball bearing from the perspectives of contact fatigue life and friction heat by gyro rotation of rolling ball was put forward. The results provide a reference for the design and application of high speed angular contact ball bearing.

According to the problem of gray cells redundant during the three-dimensional continuum static topology optimization, a density-acuity level update strategy was proposed taking the minimum flexibility of the structure as the objective function and using the topology optimization mathematical model based on the SIMP interpolation method. Took NC gear shaping machine tool bed as an example, the update strategy was used and the algorithm with MATLAB was achieved to do the three\|dimensional topology optimization. The gray cells decreased obviously in the optimization result, which illustrated the rationality of the density-acuity level update strategy.

In order to counteract the nonlinear term in companion nonlinear system, a controller can be designed to precisely linearize the nonlinear system. Generally, there are uncertain factors existing outside the system which lead to the system model uncertainty, so the controller cannot be designed directly. The uncertain term in the system model was adaptively identified by using the principle of that RBF neural network could approximate any continuous function with any precision. The identified result was provided to the controller and it realized the adaptive compensation control of the companion nonlinear system based on neural network. The designed controller was used to control swing angle subsystem of crane-load system. Experiment results showed that the swing angle of the load and the angular velocity of the swing angle were well controlled in about 5 s, and the approximation error of the uncertain term in the system model could reach zero at about 5 s; the designed controller had strong robustness against the uncertain factors of the system and the change of the system parameters.

The traditional layout of automotive seat skeleton components mainly relies on the designer's experience, which leads to low design efficiency and non-optimal structure. This paper studied the layout design method of automotive seat skeleton components for the rear seat of a car with the plate-tube structure based on structural topology optimization design technology. Firstly, according to the shape and size requirements on skeleton appearance, the design domain was determined and the design model was constructed under the belt loading state. Secondly, the structural topology optimization design was carried out on the basis of the alterable density method, in which the maximum static stiffness was set to be the design objective. According to the result of topology optimization, two different schemes were put forward. Finally, the optimal design scheme was determined by comparing the FEA results, and the collision safety analysis was carried out. The results showed the suggested design method was effective, the skeleton weight was declined by 1.92%, while the overall static stiffness increased by 19.0%, and the safety requirement of dynamic collision was satisfied. The optimal components layout of seat skeleton is obtained by using the design method.

To obtain a longitudinal-flexural coupling vibration transformer with large amplitude which met the requirements of gear ultrasonic machining, a transformer with cascades horn was designed. Based on the Mindlin‘s theory, according to the force and displacement coupling conditions between each part of the horn, between the horn and gear, and the boundary conditions, the frequency equation and the displacement amplitude equation were achieved. Then the transformer was designed and the amplitude distribution curve was obtained. The dynamic characteristics of the transformer got by mode and harmonic response analysis with the help of ANSYS were consistent with both the theoretical solution and the resonance characteristic experiment. The amplitude at the pitch circle of the gear was 12 μm, which was larger than that of the ordinary transformer and met the requirements of gear ultrasonic machining.

In order to solve the problem of Class-E power amplifier (PA) having too narrow bandwidth, an improved scheme on the input and output matching network of Class-E power amplifier was proposed. The output matching network utilized the transmission-line combining with Chebyshev low\|pass matching network in order to suppress harmonics in a wide operating bandwidth; in addition, the closed-form solution broadband band\|pass matching network in the input matching network utilized the transformation method, which could enhance the design flexibility of matching network. Based on the proposed method and the optimum source and load impedances obtained by multi-harmonic bilateral\|pull technology, a broadband high efficiency Class-E power amplifier based on CGH40010F device was designed. The measured drain efficiency was more than 65% and maximum efficiency was 83%, output power was 39-41.1 dBm and power gain was 11-13.1 dB, and gain flatness was ±1 dB at the operation of a 28 dBm input power, 28 V drain voltage and -3.3 V gate voltage in the L-band. The measurements have shown that the proposed method is well verified, and the designed Class-E PA has a wide bandwidth and high efficiency.

 In order to improve the shift quality of the automated mechanical transmission(AMT), the key factors affecting the automated mechanical transmissions shift quality was analyzed. And a new shift strategy of AMT vehicle based on engine torque and speed control was proposed. The shifting process was divided into three phases by the control strategy, and each phase implemented the joint control between the engine and the clutch, which improved the quality of AMT vehicle. To validate the above\|mentioned control strategy, a simulation model of hydraulic AMT was established based on the MATLAB/Simulink software. Rapid control prototype of transmission control unit (TCU) was set up based on dSPACE and tested on a AMT vehicle. The results of simulation and test showed that the shift strategy of AMT vehicle based on engine torque and speed control improved the shift quality and made the shifting process more comfortable.

Considering the operational principle of stepping\|type advanced supporting system on fully mechanized tunneling and the dissatisfied synchronization control problem in the process of the top beam raising, a novel fuzzy synchronous control method based on same state cross-couplingare was proposed. This method was a nonlinear synchronization control method which had combined the cross-coupling control theory with fuzzy control theory, and according to the control requirements of synchronization performance and tracking performance in the process of hydraulic cylinder rising. In order to validate the feasibility of the method, the application effect of proposed synchronous control method was discussed theoretically and experimentally compared to method by use of the master-slave cross coupling. Experimental results showed that multiple cylinders in the process of rising could be controlled synchronously by use of the above method, and the synchronous control effect could be improved effectively by contrast with master-slave cross coupling method.