摘要：The application of the adaptive growth method is limited because several key techniques during the design process need manual intervention of designers. Key techniques of the method including the ground structure construction and seed selection are studied, so as to make it possible to improve the effectiveness and applicability of the adaptive growth method in stiffener layout design optimization of plates and shells. Three schemes of ground structures, which are comprised by different shell elements and beam elements, are proposed. It is found that the main stiffener layouts resulted from different ground structures are almost the same, but the ground structure comprised by 8-nodes shell elements and both 3-nodes and 2-nodes beam elements can result in clearest stiffener layout, and has good adaptability and low computational cost. An automatic seed selection approach is proposed, which is based on such selection rules that the seeds should be positioned on where the structural strain energy is great for the minimum compliance problem, and satisfy the dispersancy requirement. The adaptive growth method with the suggested key techniques is integrated into an ANSYS-based program, which provides a design tool for the stiffener layout design optimization of plates and shells. Typical design examples, including plate and shell structures to achieve minimum compliance and maximum bulking stability are illustrated. In addition, as a practical mechanical structural design example, the stiffener layout of an inlet structure for a large-scale electrostatic precipitator is also demonstrated. The design results show that the adaptive growth method integrated with the suggested key techniques can effectively and flexibly deal with stiffener layout design problem for plates and shells with complex geometrical shape and loading conditions to achieve various design objectives, thus it provides a new solution method for engineering structural topology design optimization.

摘要：Flow characteristics inside a cyclone filter were investigated by the use of computational fluid dynamics(CFD). For computations, SST model was adopted. Parametric study was carried out considering the filtering performance. Revolution speeds were changed from 100 to 550 with 50 increments. A skirt is the driving source for cyclone operation. The influence of several design factors, such as the skirt length, the skirt gap and the return length to filtering performance was investigated under the particle diameter 100μm of debris material(Al, s.g.=2.7). The filtering performance was also investigated with the skirt length 28 mm changing the debris diameters from 1μm to 50μm. The flow rate of the working fluid was maintained at 0.55kg/s. It has been verified that the most influential factors to the filtering efficiencies was the skirt gap between the cyclone generator and the cyclone vessel.

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：For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.

摘要：Direct methanol fuel cell(DMFC)has great potential to replace the traditional battery in the field of portable power *** study investigates the operational and structural aspects of a vapor-feed semi-passive DMFC supplied with concentrated *** effectiveness of using vaporous methanol to improve the cell performance is experimentally *** indicate that there exits an optimal value of methanol concentration that favors both methanol supply and control of methanol crossover(MCO).With the increase in vaporization temperature,the cell performance can be *** on the traditional structural design,a sintered porous metal plate is further used to depress the impact of MCO so that the cell performance can be significantly improved at a relatively higher methanol *** is of great importance to enhance the energy density and operating duration for portable *** mechanisms related to the performance behaviors are discussed in detail.

摘要：Two types of coaxial self-balancing robots(CSBR)were proposed,one can be used as a mobile robot platform for parts transporting in unmanned factory or as an inspector in dangerous areas,and the other can be used as a personal transporter ridden in *** designing and control structures as well as control strategies were described and compared in order to get a general way to develop such robots.A state feedback controller and a fuzzy controller were designed for the robot using DC servo motors and the robot using torque motors,*** experiments indicate that the robots can realize various desired operations smoothly and agilely at the velocity of 0.6 m/s with an operator of 65 ***,the robustness of the controllers is revealed since these controllers can stabilize the robot even with unknown external disturbances.

摘要：本文主要介绍了华南理工大学(SCUT)在激光选区熔化(SLM)成型设备以及医用金属材料SLM成型的基础研究与应用的最新成果。首先,采用DiMetal-100设备研究316L不锈钢、CoCrMo与Ti6Al4V三种医用金属粉末SLM成型的工艺参数、微观组织和力学性能。其次,详细介绍了SLM成型316L不锈钢在个性化舌侧正畸托槽和手术导板的应用,SLM成型CoCrMo在膝关节假体和牙冠牙桥的应用,以及SLM成型Ti6Al4V在骨盆骨折接骨板和个性化颅骨修复体方面的研究成果。最后,介绍了SCUT在SLM技术方面的发展方向和研究计划,具体包括实现新型多孔结构的SLM直接成型、实现多种材料SLM一次成型、实现SLM与减材复合成型、增加SLM设备的负反馈系统以及开发陶瓷和新型金属的SLM成型工艺。总结:SCUT对SLM设备及其医学应用进行了长期深入的研究,研究了医用金属材料316L不锈钢、CoCrMo合金以及Ti6Al4V合金的SLM成型工艺和微观组织,获得了性能优异的零件。SCUT成功将SLM成型的316L不锈钢应用于舌侧正畸托槽和手术导板,将SLM成型的CoCrMo合金应用于膝关节假体和牙冠牙桥,以及将SLM成型的Ti6Al4V合金应用于个性化接骨板和颅骨多孔修复体。其中,舌侧正畸托槽和牙冠固定桥已经进入商业应用。目前,SCUT正在进一步开展面向植入体内部结构的设计和制造技术研究,同时开始对SLM多材料成型、SLM与切削复合成型进行研究,并逐步开展SLM设备负反馈系统的开发及陶瓷、锌合金、镍钛合金等SLM成型工艺的研究等。

摘要：The laser scribing of polyimide(PI, Kapton) film is a new, simple and effective method for graphene preparation. Moreover,the superhydrophobic surface modification can undoubtedly widen the application fields of graphene. Herein, inspired by the hydrophobic and self-cleaning properties of natural Oxalis corniculata Linn. leaves, we propose a novel bionic manufacturing method for superhydrophobic laser-induced graphene(LIG). By tailoring the geometric parameters(size, roughness and height/area ratio) and chemical composition, the three-dimensional(3D) multistage LIG, i.e., with micro-jigsaw-like and porous structure, can deliver a static water contact angle(WCA) of 153.5° ± 0.6°, a water sliding angle(WSA) of 2.5° ±0.5°, and great superhydrophobic stability lasting for 100 days(WCAs ≈ 150°). This outstanding water repellency is achieved by the secondary structure of jigsaw-like LIG, a porous morphology that traps air layers at the solid–liquid interface. The robust self-cleaning and anti-stick functions of 3D bionic and multistage LIG are demonstrated to confirm its great potential in wearable electronics.

摘要：The chief aim of the present work was to achieve drag reduction in stator blades with liquid using boundary layer control. A stator blade of hydraulic torque converter with bionic grooves in suction side and hydrophobic surface in pressure side was designed. The hydrophobic surface was created using anodic oxidation method and irregular A1203 thin films were found on the surface. They formed hierarchical structure consisting of mini porous structures and microscopic pore spaces, resulting in the hydrophobicity. The bionic groove was designed by Computational Fluids Dynamics （CFD） method. Multi-Island Genetic Algorithm （MIGA） was adopted for groove multi-objective optimization. Through optimization, the maximum drag reduction was close to 12% in oil. In addition, the drag reduction calculation was verified by closed channel experiment and ＂Tire Vortex＂ was proposed to explain the drag reduction mechanism. The bionic Janus blade could maintain its initial profile without any additional device, which had lower risk and less cost. The results are encouraging and show great potential to apply in other flow machineries.

摘要：In order to enhance the bearing capacity of non-circular gear pair, the non-circular gear pair with double generating angles is proposed based on the design idea of unsymmetrical gear with double pressure angles. The tooth profile is designed by generating cutting theory, the pure rolling mathematic model that the center line of unsymmetrical rack roll along non-circular pitch curve is built, the digital model of non-circular gear with double generating angles is created through the second development method of CAD software, and then the drive characteristic and tooth strength are analyzed. The results show that the design method for double generating angles non-circular gear proposed in this paper is feasible, which is significant to improve the bearing capacity of non-circular gear pair.