In order to improve product design efficiency, the dimension data transfer process in the process of change design is discussed from two aspects: the propagation of dimension change between the parts and between the key structures inside the part. Firstly, the basic logic structure of product dimension correlation design was analyzed, and the change propagation logic meta-model was established. Then, by analyzing the assembly correlation and dimension correlation among the parts, the correlation path among the parts in assembly and the propagation model of dimension correlation change were established. Taking the change part as the research object, according to the connection and constraint relationship between the internal dimensions of the part, the change propagation path for the internal dimensions of the part was established based on the part modeling process, and the dimension change propagation of the key structures inside the part was completed. Based on the above process, the whole change propagation and data transfer process analysis from the change source to the part and to the specific dimension inside the part were completed. Finally, the validity of the proposed method was verified by an example of a veneer reeling machine. The results show that this method can provide a new idea for the propagation of product dimension change, and provide a theoretical basis for improving product design efficiency.

In order to effectively record and manage all kinds of interactive non-model information in the product design process, a non-model information management method for designers was proposed. In order to record the design information accurately, objectively and comprehensively, a variety of information carrier tools were adopted visualize the information, which achieved the integrated management and sharing of model and non-model information. The method was integrated into the product design software platform and the information record and management software seamlessly, so that a set of product design non-model information management system was developed, which realized the integration of product design and information management. The example research results showed that designers could use the management system to review, describe and manage various types of non-model information generated in the product design process in real time, and realize the automatic classification and storage of information. The research indicated that the proposed management method and management system can achieve effective management of non-model information, and improve the use value of non-mode information and design quality of products.

Aiming at the problem of configuration synthesis of a planetary polishing device, a configuration synthesis method based on Assur kinematic chain (AKC) is presented. According to the composition principle of planar mechanisms, the AKC was selected as the basic unit and it was disassembled according to the different numbers of dismantled components, by which the original configurations of the mechanism were obtained. By the structural topology of the original configurations, the cognate configurations with single or multiple degrees of freedom were obtained. The redundant degrees of freedom of the cognate configurations were constrained by the double sliding block structure, sliding block parallelogram structure and bi-parallelogram structure, and 47 kinds of planar mechanism configurations which met the requirements of degree of freedom were developed. According to the requirements of avoiding mechanical interference, concise configuration and adjustable eccentricity, three configurations that met the requirements were determined, one of which was selected to design the planetary polishing device, and the feasibility of the device was verified by the motion characteristics analysis. Results indicate that the configuration synthesis method based on AKC can realize the configuration design of planetary polishing device, while this method can provide more ideas for the configuration synthesis of planar mechanisms.

At present, patent circumvention design mainly aims at the circumvention design of single patent. However, a single patent can only evade specific patent, the result of such circumvention may still have the risk of infringing other patents in this patent group. Therefore, TRIZ innovation method and patent group circumvention method were integrated, and a systematic patent group circumvention method was proposed for product innovation design. Firstly, the target patent group was determined through the Boolean operation of IPC (international patent classification) and keywords. Secondly, the patents in the patent group were linked by library components in the TRIZ method, and the total function model diagram of patent group was established through component-function analysis to determine the problems to be avoided. Thirdly, component circumvention and function circumvention as well as problem innovative methods in TRIZ were applied to obtain the preliminary solution， and the patent infringement judgment and patent portfolio application were made. Finally, taking the patent group of corn thresher as an example, this method was applied to the patent group circumvention design. A improved corn thresher was developed and applied for related patents. Corn was poured into the hopper and sent to the threshing roll by the spiral feeding device. The spiral distribution of threshing thorns on the threshing roll made the corn move forward and rotate at the same time to achieve the threshing effect. Corn cobs were collected in the dreg hopper and corn grains were collected in the hopper. The improved corn thresher has the advantages of low crushing rate, high net removal rate and high working efficiency. The example shows that the patent group circumvention method based on TRIZ effectively realizes the innovative circumvention design for existing patent groups.

Aiming at the problems that the failure reason is not easy to obtain and the release is not easy to control for the mudguard assembly of commercial vehicles, a fatigue failure solution for a single degree-of-freedom vibration system based on the measured load spectrum is proposed. Firstly, the failure mode, fracture morphology and road load spectrum of a commercial vehicle mudguard assembly were analyzed, and the failure type and system model were determined. Through the data analysis, the mudguard assembly was simplified into a single degree-of-freedom vibration system, and its equivalent stiffness was the series stiffness of the fixed bolt and mudguard bracket. Then, theZ-direction acceleration power spectral density （PSD） at the frame （the installation position of the mudguard assembly） and the end of the mudguard bracket, and the frequency response function and the coherence coefficient between them were analyzed, and the working mode of mudguard assembly was obtained. Finally, in order to improve the quality of mudguard assembly, an endurance test specification for mudguard assembly was developed based on shock response spectrum (SRS) and fatigue damage spectrum (FDS). The results showed that when the frequency was 22.0 Hz, the response of the mudguard assembly was the largest, and theZ-direction accelecation power spectral density of the frame was lower, and the coherence coefficient betweem them was only 0.6, which indicated that the failure of mudguard assembly was mainly due to its own excitated mode. While the main working mode of mudguard assembly was the third-order mode (f = 22.26 Hz), its vibration shape was anti-phase swing up and down, which was consistent with the test result. The failure mode of mudguard assembly was reproduced scientifically by bench test based on mudguard assembly endurance test specification, and the rationality of test specification was verified. Follow-up tests show that the failure rate of the improved mudguard assembly is greatly reduced and the after-sales feedback is good. The research indicates that the solution can significantly shorten the development cycle of new products, and realize the rapid release of improved products and subsequent new products.

The mass properties of the spacecraft are important parameters that affect the orbiting of the spacecraft, including mass, centroid and moment of inertia. In order to solve the problems of low precision, low measuring efficiency and backward measurement in the traditional mass property measuring methed for solar array, a high-precision, high efficiency and automated mass property measuring method for solar array was designed. An attitude adjustment device was adopted to tilt the solar array, and the weight and centroid of the solar panel were measured by taking the average of multiple measuring values. The attitude adjustment device matched the various interface forms of the solar array, which realized the 0°–60° pitch attitude adjustment of the multi-platform solar array. By combining the integrated software algorithm of the method, the automatic solution of the mass and centroid were achieved. Finally, the feasibility of the proposed method was verified by experiments. The results showed that the mass measuring accuracy of the proposed method was higher than 0.01%G（gamut）+0.1kg, the centroid measuring accuracy was higher than 0.5 mm, and the measuring time was shortened from 8 h to 40 min. On the basis of satisfying the measuring accuracy, the mass property measuring efficiency of solar array is also improved, the labor cost is saved, which lays a solid foundation for the subsequent batch production of spacecraft solar array on production lines.

In order to solve the problem that the workover string is difficult to run downhole in the high horizontal-displacement to vertical-depth ratio and the long horizontal section, the running ability of workover string with different length proportion of combined tubing was studied based on the operation of workover string with two kinds of combined tubing. Based on the characteristics of horizontal well trajectory and considering the stress condition of workover string in each well section, a load calculation model for workover string in vertical section, deflecting section and horizontal section of horizontal well was established. The model was solved by interpolation method, iteration method and segmental discriminant method, and the relevant calculation software was compiled. Based on the field data, a case study of the workover string running capability was carried out. The results showed that, when the tubing with larger line weight among the workover strings went down to the well depth at about 56.3°, the workover string had the best running ability compared with the combination of workover string body and single line heavy tubing or two kinds of line heavy tubing with different length proportions. Research results can provide guidance for the safe running of workover string in horizontal well.

At present, adjusting the clearance between the sliding shoe and the guide plate and determining the lubricating oil supply flow of the fracturing pump only relies on worker’s experience, which lacks of scientific basis and theoretical guidance. As a result, the wear and burning tile of sliding shoes and guide plate occur from time to time, which seriously reduces the service life of the fracturing pump and affects the production safety of fracturing operations. Therefore, for the 6000HP fracturing pump, the frictional heat generation and heat dissipation mechanism between the sliding shoe and the guide plate of fracturing pump under the action of lubricating oil was studied, and the influence law of the clearance between the sliding shoe and the guide plate and the oil supply flow on the lubrication and cooling status of fracturing pump was derived. At the same time, the validation test was carried out on the testing platform of fracturing pump. The results showed that as the clearance between the sliding shoe and the guide plate decreased, the change in lubricating oil temperature was more obvious. When the clearance between the sliding shoe and the guide plate was less than 0.2 mm, the temperature of the lubricating oil would reach 360 K, which had exceeded the allowable working temperature of the selected lubricating oil. The increase in the oil supply flow of the lubricating oil could reduce the the lubricating oil temperature, but when the oil supply flow exceeded 2 L/min, the effect of oil supply flow on the the lubricating oil temperature was not significant. Research results provide a theoretical basis and design reference for the reasonable selection of the clearance between the sliding shoe and the guide plate and the lubricating oil supply flow.

Aiming at the optimization design of deployable mechanism of a new type of scissor folding bridge, the kinematics and statics models of the deployable mechanism were established at first. Then, the key hinge position of the deployable mechanism and the angle between the side bridge section and the vertical direction were selected as the variables for optimization design. The spatial position of the deployable mechanism was selected as the main constraint condition. Meanwhile, the optimization target was defined as minimizing the peak force of deployable bridge cylinder, linkage and the key hinge points. After the multi-optimization targets were normalized and weighted, the multi-objective optimization analysis model of the deployable mechanism was constructed. The genetic algorithm and nonlinear programming (GA-NLP) hybrid approach was used to solve the multi-objective optimization model. The correctness of the multi-objective optimization model of the deployable mechanism was verified by ADAMS software. The research results showed that the peak pulling force and pushing force of deployment mechanism cylinder decreased by 57.9% and 25.3% respectively. The peak pulling force and pressure of linkage decreased by 26.1% and 55.2% respectively， and the peak force of two key hinge points of deployable mechanism decreased by 23.5% and 26.8% respectively. The research results can provide a theoretical basis for the optimization design of the deployable mechanism.

In the field of precision engineering, it is a research hotspot to realize the flexibility and stability of operation simultaneously. Single-stage compliant orthogonal displacement amplification mechanism can realize parallel grasping by orthogonal displacement transformation, and improve the flexibility of operation through displacement amplification. However, the traditional modeling method for this mechanism is mainly based on the small deflection assumption and ignores the shearing effect, which results in a lower model precision. For this reason, the precise nonlinear modeling and optimization of typical single-stage compliant orthogonal displacement amplification mechanism with single-force input were carried out. Considering the shearing effect and geometric nonlinear factors, the output displacement of the mechanism was modeled by a two-step semi-analytical method, which realized the rapid prediction of nonlinear results. Firstly, based on the energy method and the Euler-Bernoulli beam theory, the linear elastic analytical model of the output displacement of this mechanism was established, and the shearing nonlinear correction coefficient was fitted by using the small deflection-based static finite element analysis. Secondly, combining the geometric nonlinear static finite element analysis with numerical fitting, the geometric nonlinear correction coefficient model of the output displacement of this mechanism was established. In order to maximize the output displacement and suppress the geometrical nonlinearity, a comprehensive optimization strategy for the planar dimensions and thickness of this mechanism was proposed. The effectiveness of nonlinear output displacement model and optimization results of this mechanism were verified by ANSYS Workbench finite element simulation. Simulation results showed that the errors of nonlinear output displacement model for this mechanism was smaller than 5%, and according to different optimizing strategies, the output displacement could be effectively improved, or the geometrical nonlinearity could be restricted to a designated range. The research indicates that using the proposed method to conduct the nonlinear model and optimization of the single-stage compliant orthogonal displacement amplification mechanism, the displacement output performance, open-loop controlling accuracy and real-time performance of compliant mechanism-based piezoelectric-driven microgripper can be effectively improved, which is conducive to realize the stable and smart micro-manipulation.

In order to study the influence of parameters of sand-throwing plate of railway sand cleaning vehicle on the sand-throwing height and distance, a discrete element orthogonal test method was proposed to optimize the parameters of sand throwing plate and improve the sand-throwing height and distance. By means of orthogonal experiments and discrete element method (DEM), the effects of rotational speed, bending angle, bending position and forward speed of sand throwing plate on the sand-throwing height and distance were analyzed.The gray analysis and range analysis were used to analyze the experiment results to obtain the best parameter combination and it was verified on the test platform.The simulation results showed that the rotational speed was the most important factor affecting the sand-throwing height and distance. Under the condition that the radius of the sand throwing plate remained unchanged, the best parameters were rotation speed of 2 r/s, bending angle of 170°, bending position of 5/6 and forward speed of 1 km/h. The test results showed that after parameter optimation, the sand-throwing height and distance were reduced by 8.64% and 32.3%， respectively. This shows that the optimized send cleaning vehicle not only meets the design requirements, but also reduces the energy consumption and the impact of sand particles on the sand throwing plate. The research results provide a theoretical basis for the development of sand cleaning vehicle.

Due to the measurement errors caused by cross-sensitivity in the quantitative analysis of flammable and explosive mixture gas and the difficulty of parameters determination in least squares support vector machine (LSSVM), a LSSVM optimized by improved artificial bee colony (IABC) algorithm was proposed. Firstly, to improve the accuracy of convergence, the adaptive decreasing factor was introduced to update the step and the following probability formula of waiting worker bee was modified by combining the roulette and reverse roulette on the basis of the artificial bee colony (ABC) algorithm. Then, the penalty parameterC and the kernel parameter σ² of the LSSVM were optimized by IABC algorithm. Finally, the quantitative analysis model of LSSVM was reconstructed by these optimized parameters, and compared with the quantitative analysis model of LSSVM optimized by particle swarm optimization (PSO) algorithm, which was a commonly used quantitative analysis method of mixture gas. The experimental results showed that under the cross-sensitive state, the modeling total time and the concentration measuring average relative error of each component gas with the LSSVM optimized by IABC algorithm were lower than those with the LSSVM optimized by PSO algorithm，which effectively improved the concentration measuring accuracy of the mixture gas. The research shows that the LSSVM optimized by IABC algorithm can provide theoretical support for quantitative analysis of mixture gas, and has certain engineering application value.

Based on the advantages of micro-dimpled surface textures in improving the sealing performance of mechanical end face, a new type of Reuleaux triangular micro-dimpled surface texture was proposed, and the sealing performance of textured end face was investigated by numerical simulation. Firstly, three kinds of micro-dimpled surface textures of circular, triangular and Reuleaux triangular shapes were set on the surface of the rotating ring. Then, the meshes of three kinds of micro-dimpled textured sealing end face models were generated by GAMBIT software and the flow field characteristics of the sealing end face were analyzed by Fluent software, and the pressure distribution of the flow field of the sealing end face was obtained. Finally, the variation rules of opening force, leakage rate and the ratio of opening force to leakage rate of the textured sealing end face of the three types micro-dimpled textured sealing end faces with the texture area ratio, hole depth, seal gap, operating pressure and rotational speed were summarized. The results showed that the opening force and leakage rate of the three kinds of micro-dimple textured sealing end face had the same variations with the sealing parameters. WhenS_p=10%,h_d=3~4 μm,h_p<3 μm,p_i<0.3 MPa, the three kinds of micro-dimpled textured sealing end face showed preferable sealing performance. Compared with the circular and triangular micro-dimpled textured sealing end faces, the Reuleaux triangular micro-dimpled textured sealing end face had larger opening force, smaller leakage rate and larger ratio of opening force to leakage rate. The research results can provide reference for the sealing parameter optimization design of mechanical end face of micro-dimpled surface texture.

To identify the key geometric error terms which affect the space precision of the worm wheel gear grinding machine, a geometric error sensitivity analysis method based on the screw theory and Sobol method is proposed. The YW7232 worm wheel gear grinding machine was taken as the research object. Firstly, the geometric error model of the machine tool was established based on the screw theory. Then, the sensitivity coefficient of each geometric error term to the spatial error component of the machine tool during the grinding process was calculated by using Sobol method and the key geometric error terms were identified. Finally, after correcting the key geometric error terms of the machine tool， the spatial error component of the machine tool before and after correction and the rod length of the ballbar in the three measurement modes were compared by simulation analysis. The simulation results show that the proposed method can effectively identify the key geometric errors in the grinding process of the machine tool， and provide theoretical guidance for improving the precision of the machine tool.

Vacuum insulation cold mass support (CMS) is one of the key supporting components in the International Thermonuclear Fusion Reactor (ITER). In order to detect whether the performance of the manufactured CMS meets the acceptance criteria, it is necessary to conduct a friction performance test and a mechanical strength test before delivery. By analyzing the loading characteristics of the CMS under the complex working conditions, combining the friction test standard ASTM D1894-14 and the engineering calculation results of friction force, a CMS friction performance test platform was designed. Based on the loading conditions of CMS, a CMS mechanical strength test platform was initially designed, and the 10 I-beam was selected as the best meterial for the moment beam through the force analysis of the moment beam. Then, the hydraulic servo device was used to apply working load to the CMS, and the structural design of the equipment and tools related to the mechanical strength test platform was completed. Considering the individual costs of friction performance test and mechanical strength test, a CMS performance integrated test platform was designed through combining with the features of two tests. The results indicate that the CMS performance integrated test platform can shorten the test cycle and reduce the test cost, which provides guarantee for the engineering quality certification and subsequent mass production of CMS.

Isolator is an important basic part of the slewing bearing. In order to investigate the influence of working parameters on the performance of the isolator, the performance tests of common isolator materials PA1010 and HPb59-1 mating for bearing steel GCr15 were conducted individually by using M-2000 testing machine，and the effects of load, rotating speed and lubricant on the friction coefficient and wear amount of PA1010 and HPb59-1 were discussed. Through observing the micro-morphology of the wear surface, the damage mechanisms and failure laws of PA1010 and HPb59-1 were deduced, respectively. The results indicated that the friction coefficient of PA1010 was lower than that of HPb59-1, and the average ratio of PA1010 to HPb59-1 was 1∶1.27. The wear amount of PA1010 was higher than that of HPb59-1, and their average ratio was 1.51∶1. The effect of the load and rotating speed on the tribological properties of HPb56-1 was obviously higher than that of PA1010. The friction coefficient and wear amount of PA1010 and HPb59-1 when using 20^# oil lubrication were lower than those when using No.2 lithium grease. The friction coefficient of PA1010 decreased by 46.2% and the wear amount decreased by 28.7%, while the friction coefficient of HPb59-1 decreased by 43.8% and the wear amount decreased by 29.8%. The research results provide references for the mechanical design of slewing bearing isolators.