摘要：For optimal design of constant stress accelerated life test（CSALT） with two-stress, if the stresses could not reach the highest levels simultaneously, the test region becomes non-rectangular. For optimal CSALT design on non-rectangle test region, the present method is only focused on non-rectangle test region with simple boundary, and the optimization algorithm is based on experience which can not ensure to obtain the optimal plan. In this paper, considering the linear-extreme value model and the optimization goal to minimize the variance of lifetime estimate under normal stress, the optimal design method of two-stress type-I censored CSALT plan on general non-rectangular test region is proposed. First, two properties of optimal test plans are proved and the relationship of all the optimal test plans is determined analytically. Then, on the basis of the two properties, the optimal problem is simplified and the optimal design method of two-stress CSALT plan on general non-rectangular test region is proposed. Finally, a numerical example is used to illustrate the feasibility and effectiveness of the method, The result shows that the proposed method could obtain the optimal test plan on non-rectangular test regions with arbitrary boundaries. This research provides the theory and method for two-stress optimal CSALT planning on non-rectangular test regions.

摘要：Former knowledge engineering research aimed at boosting automatic *** recent knowledge management research focused on promoting the knowledge sharing and reusing among the *** of the different aims between the two directions,former knowledge representation schemata,such as rule based representation,frame from knowledge engineering research does not fit to the current knowledge management *** this paper,for the purpose of building knowledge management systems for product design enterprises,knowledge items are classified into seven types based on the semantics of their *** their representations are discussed *** on the above classification,a knowledge representation meta-model and a basic domain ontology reference model for cooperative knowledge management systems are put *** reference model is an abstraction that can be reused and extended in knowledge management systems of different ***,the patterns of knowledge acquisition processes in cooperative knowledge management scenarios of product design processes are studied.

摘要：This paper aims at the elastic buckling of multilayered thin-walled conical shells with power-law distributed material properties under the axial load and lateral pressure based on the experimental study of palm trunks. The material properties of the shells are assumed to vary continuously in the radial direction. Relations and analytical approaches for linear buckling response are presented by using the layer-wise shell theory. The buckling behaviors of the conical shells subjected to axial and transverse loads are investigated. Parametric study in geometry(relative thickness, relative stiffness and cone angle) is performed to enhance the overall buckling resistance and minimize the weight. Numerical results show the possibility to achieve larger load-carrying capacity by simultaneously optimizing the material and geometric parameters based on the structure of palm trunks.

摘要：This work investigates the machining temperatures of ultra-fine-grained titanium(UFG Ti),prepared by equal channel angular extrusion,through analytical *** Ti has great usefulness in biomedical applications because of its high mechanical strength,sufficient manufacturability,and high *** temperatures were predicted using a physics-based predictive model based on material constitutive relation and mechanics of the orthogonal cutting *** minimization between the stress calculated using Johnson–Cook constitutive model and the same stress calculated using mechanics model yields the estimation of machining temperatures at two deformation *** agreements are observed upon validation to the values reported in the *** machinability of UFG Ti is investigated by comparing its machining temperature to that of Ti–6Al–4V alloy under the same cutting *** lower temperatures are observed in machining UFG *** computational efficiency of the presented model is investigated by comparing its average computational time(~0.5 s)to that of a widely used modified chip formation model(8900 s)with comparable prediction *** work extends the applicability of the presented temperature model to a broader class of materials,specifically ultra-fine-grained *** high computational efficiency allows the in situ temperature prediction and optimization of temperature condition with process parameters planning.

摘要：Topology optimization design of continuum structures that can take account of stress and displacement constraints simultaneously is difficult to solve at present. The main obstacle lies in that, the explicit function expressions between topological variables and stress or displacement constraints can not be obtained using homogenization method or variable density method. Furthermore, large quantities of design variables in the problem make it hard to deal with by the formal mathematical programming approach. In this paper, a smooth model of topology optimization for continuum structures is established which has weight objective considering stress and displacement constraints based on the independent_continuous topological variable concept and mapping transformation method proposed by Sui Yunkang and Yang Deqing. Moreover, the approximate explicit expressions are given between topological variables and stress or displacement constraints. The problem is well solved by using dual programming approach, and the proposed element deletion criterion implements the inversion of topology variables from the discrete to the continuous. Numerical examples verify the validity of proposed method.

摘要：In order to investigate the design method for a micro centrifugal compressor, which is the most important component of an ultra micro gas turbine, two types of centrifugal impeller with 2-dimensional blade were designed, manufactured and tested. These impellers have different shapes of hub on the meridional plane with each other. Moreover, these types of impeller were made for the 5 times and the 6 times size of the final target centrifugal impeller with the outer diameter of 4ram in order to assess the similitude for the impellers. The comparison among the performance characteristics of the impellers revealed the influence of the meridional configuration on the performance and the similitude of the compressors.

摘要：Kirigami, the ancient Japanese paper cutting technique, has been applied to achieve high stretchability and low energy loss of designed metallic glass. Despite the exploration of the underlying deformation mechanism of kirigami-inspired structures from the energy point of view, the morphable responses of the kirigami patterns and the origin of the kirigami response are yet to be fully understood. This study reveals the mechanical driven-forms of the kirigami structure with the corresponding deformation stages. Based on the beam deflection theory, the elastic buckling behavior of kirigami metallic glass is manifested and a critical force prediction model is developed. Moreover, a force concentration parameter is introduced in the rigid-plastic deformation stage, predicting the nominal ultimate force. The kirigami-inspired facture force is firstly proposed. The findings of these models are in good agreement with the experimental sizedependent kirigami responses, and expected to provide significant insights into the understanding of the deformation behavior and the design of kirigami metallic glasses.

摘要：The influence of rock dust size（10-30 μm） and mass fraction（5%-15%） on density, hardness and dry sliding wear behavior of Al 6061/rock dust composite processed through stir casting was investigated. Wear behavior of the developed composite was characterized at different loads, sliding velocities and distances using pin-on-disc setup. The experiments were conducted based on Taguchi＇s L27 orthogonal array and the influence of process parameters on wear rate was studied using ANOVA. The experimental results reveal that the applied load and reinforcement size are the major parameters influencing the specific wear rate for all samples, followed by mass fraction of reinforcement, sliding velocity and sliding distance at the level of 47.61%, 28.57%, 19.04%, 9.52% and 4.76%, respectively. The developed regression equation was tested for its accuracy and made evident that it can be used for predicting the wear rate with minimal error. With the help of SEM images, the worn surfaces of the novel composite were studied and the analysis proves that the wear resistance of aluminium alloys can be well improved with the addition of rock dust as reinforcement.

摘要：Aerodynamic optimization design of compressor blade shape is a design challenge at present because itis inherently a multiobjective problem. Thus, multiobjective Genetic Algorithms based on the multibranch simulated annealing selection and collection of Pareto solutions strategy have been developedand applied to the optimum design of compressor cascade. The present multiobjective design seeks highpressure rise, high flow turning angle and low total pressure loss at a low inlet Mach number. Paretosolutions obtain the better aerodynamic performance of the cascade than the existing Control DiffusionAirfoil. From the Pareto solutions, the decision maker would be able to find a design that satisfies hisdesign goal best. The results indicate that the feasibility of multiobjective Genetic Algorithms as amultiple objectives optimization tool in the engineering field.

摘要：The different conditions of use of a component result in a variety of damage ***,excluding differences in shape and size,used parts show a high degree of uncertainty regarding failure characteristics,quality conditions,and remaining life,which seriously affects the efficiency of a remanufacturing scheme *** to address this problem,a remanufacturing scheme design method based on the reconstruction of incomplete information of used parts is ***,the remaining life of the reconstructed model is predicted by finite element analysis,and the demand for the next life cycle is ***,the scanned 3D damage point cloud data are registered with the original point cloud data using the integral iterative method to construct a missing point cloud model to achieve the restoration of geometric ***,according to reverse engineering and laser cladding remanufacturing,the tool remanufacturing process path can be generated by the tool contact point path section line ***,the proposed method is adopted for turbine blades to evaluate the effectiveness and feasibility of the proposed *** study proposes a remanufacturing scheme design method based on the incomplete reconstruction of used part information to solve the uncertain and highly personalized problems in remanufacturing.