摘要：Fail-safe topology optimization is valuable for ensuring that optimized structures remain operable even under damaged *** selectively removing material stiffness in patches with a fixed shape,the complex phenomenon of local failure is modeled in fail-safe topology *** this work,we first conduct a comprehensive study to explore the impact of patch size,shape,and distribution on the robustness of fail-safe *** findings suggest that larger sizes and finer distribution of material patches can yield more robust fail-safe ***,a finer patch distribution can significantly increase computational costs,particularly for 3D *** keep computational efforts tractable,an efficient fail-safe topology optimization approach is established based on the framework of multi-resolution topology optimization(MTOP).Within the MTOP framework,the extended finite element method is introduced to establish a decoupling connection between the analysis mesh and the topology description *** examples demonstrate that the developed methodology is 2 times faster for 2D problems and over 25 times faster for 3D problems than traditional fail-safe topology optimization while maintaining similar levels of robustness.

摘要：Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which satisfy the stiffimss and rotational speed required to the spindle. A general full factorial design method was used to verify some factors that affect the natural frequency of a spindle. It is verified that the shorter shaft length and bearing span length represent the higher natural frequency, and there are some effects according to the change in the levels of factors. The detailed spindle dimension is determined by applying an EVD method, which can define the optimal bearing position through considering the limiting condition. Based on the estimated regression model, the optimal spindle size and bearing distance that can improve the primary natural frequency are obtained, and the influence of design factors on the natural frequency is also analyzed.

摘要：The wear rate between the rotors of a hypotrochoidal gear pump is *** the knowledge of shape design on the rotors,the contact stresses without hydrodynamic effect between the rotor teeth were evaluated through the calculation of the Hertzian contact *** on the above results and the sliding velocity between the rotors,a genetic algorithm (GA) was used as an optimization technique forminimizing the wear rate proportional factor (WRPF).The result shows that the wear rate or the WRPF can be reduced considerably,*** 12.8%,throughout the optimization using GA.

摘要：Thermal performance was the most important factor in the development of borehole heat exchanger utilizing geothermal energy. The thermal performance was affected by many different design parameters, such as configuration type and borehole size of geothermal heat exchanger. These eventually determined the operation and cost efficiency of the geothermal heat exchanger system. The main purpose of this work was to assess the thermal performance of geother^nal heat exchanger with variation of borehole sizes and numbers of U-tubes inside a borehole. For this, a thermal response test rig was established with line-source theory. The thermal response test was performed with in-line variable input heat source. Effective thermal conductivity and thermal resistance were obtained from the measured data. From the measurement, the effective thermal conductivity is found to have similar values for two- pair type （4 U-tubes） and three-pair type （6 U-tubes） borehole heat exchanger systems indicating similar heat transfer ability. Meanwhile, the thermal resistance shows lower value for the three-pair type compared to the two-pair type. Measured data based resistance have lower value compared to computed result from design programs. Overall comparison finds better thermal performance for the three-pair type, however, fluctuating temperature variation indicates complex flow behavior inside the borehole and requires further study on flow characteristics.

摘要：热处理是金属材料热机械加工的常用手段.随着热处理温度的升高而湮灭的缺陷通常导致材料的塑性提升而强度降低.本研究中,我们通过提高热处理温度促进相溶解而协同提升了TiZrNbTa高熵合金的强度和塑性.当热处理温度从800提升至1250°C,合金的拉伸屈服强度提高了40%,达到1003±16 MPa.同时,合金的伸长率增加了近一倍,达到16.79%±1.03%.热处理温度提升引起的相溶解加剧了晶格畸变,从而增强了晶格摩擦应力并提升了屈服强度.相溶解也降低了界面失配并缓解了应力集中.此外,1250°C热处理合金中的局部化学有序结构促进了位错共平面滑移和位错增殖.两种机制共同提升了合金的塑性.该研究不仅扩展了关于金属材料中热处理和相溶解的理解,而且也为合金的强韧化设计提供了思路.

摘要：The application of work strategies taking into account, from the initial stages, all the factors involved in the product design process is considered essential by the researches to generate higher quality products, assess users’ needs and anticipate design problems. This paper presents two approaches of design project development, denominated respectively: projects with imposed specifications and projects with derived specifications and proposes the use of the matrix that integrates specifications and design factors (SFM). This design support tool complements others already used in the development of product concepts by higher education students, increasing the capacity of synthesis and structuring of information in order to facilitate decision-making into the design process. Its elaboration implies understanding of objectives, identifying of factors and establishing of specifications. At the same time, it aims to foster the reflection process and an integrated information analysis. The application of SFM and its contribution to different project approaches are shown in this paper.

摘要：The objective of this work was the planning, simulation and evaluation of the behavior and interactions of diverse factors in the deep drawing process, in order to prevent defects on formed metal sheet parts. The material used is austenitic stainless steel of 0.4 mm of thickness. Due to the potential high number of experiments, a preliminary selection of cylindrical and hemispherical cup drawing geometries was carried out, as well as a parametric analysis of parts and tools. The influence of the punch and die transition radii, as well as the force of the binder, on the maximum thinning suffered by the material, was studied. The tests were planned by means of CAD/CAE and the design of experiments method. After running the simulation with AutoForm, they were evaluated with FLD, Regression, ANOVA, Six Sigma and Pareto analysis. This sequence allowed us to analyze the influence and sensitivity of several tool and process design parameters and to optimize the process. The results of this investigation have also proven to be useful to simplify and accelerate the design of deep drawing tools.