摘要：The shape and thickness of the dome were investigated with the aim of optimizing the type II CNG storage vessels by using a finite element analysis technique. The thickness of the liners and reinforcing materials was optimized based on the requirement of the cylinder and dome parts. In addition, the shape of the dome, which is most suitable for type lI CNG storage vessels, was proposed by a process of review and analysis of various existing shapes, and the minimum thickness was established in this sequence： metal liners, composite materials and dome parts. Therefore, the new proposed shape products give a mass reduction of 4.8 kg（5.1%）

摘要：As energy crisis and environment pollution all around the world threaten the widespread use of fossil fuels,compressed natural gas(CNG)vehicles are explored as an alternative to the conventional gasoline powered *** of the limited space available for the car,the composite pressure vessel(TypeⅡ)has been applied to the CNG vehicles to reach large capacity and weight lightening *** pressure vessel(TypeⅡ)is composed of a composite layer and a metal *** metal liner is formed by the deep drawing and ironing(D.D.I.)process,which is a complex process of deep drawing and *** cylinder part is reinforced by composite layer wrapped through the filament winding process and is bonded to the liner by the curing *** this study,an integrated design method was presented by establishing the techniques for FE analysis of entire processes(D.D.I.,filament winding and curing processes)to manufacture the CNG composite pressure vessel(TypeⅡ).Dimensions of the dies and the punches of the 1 st(cup drawing),2 nd(redrawing-ironing 1-ironing 2)and 3 rd(redrawing-ironing)stages were calculated theoretically,and shape of tractrix die to be satisfied with the minimum forming load was suggested for life improvement and manufacturing costs in the *** of the composite material was determined in the filament winding process,finally,conditions of the curing process(number of heating stage,curing temperature,heating rate and time)were proposed to reinforce adhesive strength between the composite layers.

摘要：We review a recent work on masses of mesons and nucleons within a hard wall model of holographic QCD in a unified *** order to treat meson and nucleon properties on the same footing,we introduced the same infrared （IR） cut for both *** framework of present approach,the best fit to the experimental data is achieved introducing the anomalous dimension for baryons.

摘要：This paper presents the performance evaluation of a regenerative pump to increase its efficiency using optimal design method. Two design parameters which define the shape of the pump impeller, are introduced and analyzed. Pump performance is evaluated by numerical simulation and design of experiments(DOE). To analyze three-dimensional flow field in the pump, general analysis code, CFX, is used in the present work. Shear stress turbulence model is employed to estimate the eddy viscosity. Experimental apparatus with an open-loop facility is set up for measuring the pump performance. Pump performance, efficiency and pressure, obtained from numerical simulation are validated by comparison with the results of experiments. Throughout the shape optimization of the pump impeller at the operating flow condition, the pump efficiency is successfully increased by 3 percent compared to the reference pump. It is noted that the pressure increase of the optimum pump is mainly caused by higher momentum force generated inside blade passage due to the optimal blade shape. Comparisons of pump internal flow on the reference and optimum pump are also investigated and discussed in detail.

摘要：Flow distribution in branch piping system is affected by flow characteristics and different geometric variations. Most of the flow distribution studies are performed with one-dimensional analysis to yield overall information only. However, detailed analysis is required to find effects of design parameters on the flow distribution. For this aspect, three-dimensional turbulent flow analysis was performed to assess turbulence model performance and effects of upstream pressure and branch pipe geometry. Three different turbulence models of standard k-e model, realizable k-e model and standard k-co yield similar results, indicating small effects of turbulence models on flow characteristics analysis. Geometric variations include area ratio of main and branch pipes, branch pipe diameter, and connection shape of main and branch pipes. Among these parameters, area ratio and branch diameter and shape show strong effect on flow distribution due to high friction and minor loss. Uniform flow distribution is one of common requirements in the branch piping system and this can be achieved with rather high total loss design.

摘要：The use of commercial products such as a cup and liner for total hip arthroplasty for patients with severe bone defects has a high probability of *** these patients the cup alone cannot cover the bone defect,and thus,an additional augment or cage is *** this study,we designed three-dimensional(3D)printable bone augments as an alternative to surgeries using reinforcement ***-five sharp-edged bone augments of various sizes were 3D printed.A biporous structure was designed to reduce the weight of the augment and to facilitate bone *** types of frames were used to prevent damage to the augment’s porous structure and maintain its stability during ***,two types of holes were provided for easy augment fixation at various *** tests were performed on a combination of worst-case sizes derived using finite element *** test results confirmed the structural stability of the specimens at a load of 5340 *** the porosity of the specimens was measured to be 63.70%,it cannot be said that the porous nature was uniformly distributed because porosity tests were performed locally and *** summary,3D-printable biporous bone augments capable of bonding from various angles and bidirectionally through angulation and bottom-plane screw holes are *** mechanical results with bone augments indicate good structural safety in ***,further research is necessary to study the clinical applications of the proposed bone augment.

摘要：对于风敏感建筑,其表面风压、风力场重构与预测在主体结构风致响应计算和围护结构风荷载设计时具有重要作用。为此,基于刚性模型测压风洞试验,采用本征正交分解(proper orthogonal decompositions,POD)方法,研究了方形截面高层建筑表面风压场在开阔和城市两种地貌下的作用机理及风压、风力重构与风压预测过程。通过分析主坐标和原始广义力的频谱特性并对比二者相关特性,定量分析了前三阶特征模态分别与顺、横风向广义风力的确定性联系。研究表明:在重构风压、风力时,可以采用低阶主坐标重构时程的均方值占试验时程均方值的占比确定参与重构的模态;重构所得点风压、层间风力和广义风力达到同样精度时参与模态数不断降低,且重构所得顺、横风向广义风力仅需单一主导模态参与;采用部分测点脉动风压对驻点高度典型风压进行预测,与测压试验时程、均方根和功率谱对比发现,预测精度较高。

摘要：高层建筑数量多、分布广,其抗风问题受到广泛重视。为全面总结高层建筑风压和风荷载特性,文章对前人研究进行综述,并对来流顺风向风速与方形断面高层建筑模型表面风压开展同步测量。分析风速-迎风面风压准定常理论关系和风速-风压/力气动导纳,及建筑各表面点风压时特性、频特性、空间分布特性、概率分布特性和空间相干性;阐明迎-背风面阻力相关性,明确两侧风面升力间相关性并分析横风向升力的时、频特性;通过相平面轨迹和相关函数研究了正风向下基底弯矩和扭矩相关性。最后明确了当风向变化时,基底弯矩和扭矩时特性、频特性、(非)高斯特性及互相关特性的变化规律。在综合前人研究的同时,系统明晰风速-风压-风力的传递关系,完整阐述高层建筑表面风压和风荷载的时、频特性,全面概括了高层结构抗风设计过程中风荷载基本概念。

摘要：随着经济的快速增长,区域民众收入水准呈现不断上升的趋势,为了促进消费,而导致汽车数量的不断增加,道路交通持续发展却存在着严重问题。具有代表性的城市大众交通的消费则造成了步行者环境的逐步恶化,在某些城市,这种状况已经十分严重。为了解决此一问题,研究步行环境的改善方案是非常必要的。针对韩国光州广域市骨干道路以及流动人口不断增加带来的步行空间不充分的问题,以综合公共汽车站为例,探讨道路和步行者的特性和汽车站的属性,进行有效合理的整治,制定在特定的区域内,兼顾步行环境和道路环境设施的使用者而进行的公共汽车站设计方法。

摘要：Cavity resonance noise of passenger car tires is generated by interacting excitation between a tire structure and the fill gas (air), and generally lies in a frequency range of 200?250 Hz. As such, this noise is strongly perceived and may be a serious source of driver annoyance. Thus, many studies regarding the cavity noise mechanism and its reduction have already been conducted. In this work, a vibro-acoustic coupled analysis was conducted between a tire structure and air cavity. Using this analysis, we can more accurately simulate the tire noise performance in the region of the cavity resonance frequency. An analysis of the effects of variation of tire contour design factors was conducted, using design-of-experiments methods. Finally, a multi-objective optimization was performed using in-house codes to reduce the cavity noise level while minimizing the loss of other performances, such as diminished ride comfort and handling caused by the variations of contour. As a result of this optimization, an optimized contour shape was derived, which satisfied the multi-objective performances.