Performance-driven design methodology for habitation shell design in extreme conditions on Mars

The research project illustrates how performance-driven design tools can be conducted as an architectural design methodology that suggests an innovative approach to design a habitation shell in extreme environmental conditions without human assistance.This research study attempts to use environmental data revealed by NASA and its habitat design requirements to develop a conceptual design for an innovative habitation form and then simulate it with Mars conditions to analyze the habitation shell’s structural behavior according to finite element analysis.In this regard,research phases,including layout configuration,form-finding,and structural analysis,have been conducted to explore a habitation concept implemented with generative design tools as a decision-maker in extreme conditions.In conclusion,two generated typologies of proposed habitation forms will be compared in terms of their structural performance under extreme loads of the martian environment.Within this research project,due to the numerous extreme challenges of design and construction of habitation in extreme conditions using conventional approaches,a performance-driven design methodology will provide a rational and sustainable design methodology to tackle extreme barriers to Mars’s environment.

Structural optimum design of bistable cylindrical shell for broadband energy harvesting application

The shallow cylindrical structure is suitable to develop broadband vibration energy harvesters due to the property of the inherent mechanical bistability. In this letter, the optimum design of the bistable cylindrical shell for broadband energy harvesting application is investigated from the structural point of view. The output power is evaluated by the concept of the harvestable power, which balances the frequency of snap through and the referred output energy associated with each snap through. The non- dimensional harvestable power is analytically expressed as the function of the non-dimensional curvature parameter and one constructed parameter. The universal dependence of the optimal curvature parameter and the associated optimal harvestable power on the constructed parameter is derived, which can be well aooroximated by the linear relation in double logarithmic coordinate.

Key Techniques and Applications of Adaptive Growth Method for Stiffener Layout Design of Plates and Shells

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.

Design of Steam Turbine for Electric Power Production Using Heat Energy from Palm Kernel Shell

The steam turbine is a prime mover that converts kinetic energy in steam into rotational mechanical energy through the impact or reaction of the steam against the blades. The aim of this study is to design a steam turbine for a small scale steam power plant with target of producing electricity. The turbine is driven by the heat energy from palm kernel shells as a renewable energy source obtained at a lower or no cost. The study was concentrated on design of turbine elements and its validation using computer packages. Specifically, the microturbine design was limited to design, modeling, simulation and analysis of the rotor, blades and nozzle under the palm kernel shell as fuel for the micro power plant. In blade design, stress failures, efficiency and blade angle parameters were considered. In casing volume design, the overall heat transfer and mean temperature, and different concepts were applied. The thermal distribution on stator and rotor was considered in order to determine its level of tolerance. The design software packages used for design validation were Solidworks and Comsol Multiphysics for analysis. Simulation results showed that the designed steam turbine can adequately tolerate change in stress/load, torsion/compression, temperature and speeds.

Design Scheme of New Type Shell Raising and Feeding System of Medium-large Caliber Naval Gun

The medium -large caliber naval gun is still playing an important role in modern war. The development of highly automatic Shell Raising and Feeding System (SRFS) in the world has been briefly outlined. Several typical SRFS of medium-large caliber naval guns have been analyzed. A re-design of the system is introduced, in which systematic design method has been used to demonstrate its feasibility. The design goal of the system is to realize rapid shell feeding, with application to many types of shells, quick change of shell types , accurate and reliable feeding operation, simple mechanical structure and easy realization of shell withdrawing.

The Key Path of the Shape Optimization Design of Isotropic Material Pressure Vessels

An optimization design was conducted for the shape of the pressure vessel with a thin-shell shell. During this process, the optimization calculation was performed with the aid of the genetic algorithm toolbox included in Matlab. Firstly, through the parametric modeling function of APDL, models such as arc-shaped, parabolic, elliptical, and those generated by the fitting curve command were successfully constructed. Meanwhile, the relevant settings of material properties were accomplished, and the static analysis was conducted. Secondly, the optimization calculation process was initiated using the genetic algorithm toolbox in Matlab. Eventually, through analysis and judgment, the model generated by the fitting curve command was relatively superior within the category of the best shape.

Design of A Bionic Spudcan and Analysis of Penetration and Extraction Performances for Jack-up Platform

The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.

基于Shell脚本的气象报文迟发漏发监控程序设计与实现

介绍了西北地区迟发、漏发气象报文的监控现状,指出迟发、漏发情况对西北地区民航气象工作的影响,并提出解决方案。设计并实现了基于Shell脚本的气象报文迟发漏发监控程序。该程序通过对各个分局和航站的报文发送时间进行提取和显示,可实现对气象报文发送情况的跟踪监控,可达到严查迟发、漏发气象报文的目的,以提高西北民航气象发报准确率。

Shell煤气化技术在我国的应用前景及设计实践

在介绍煤气化技术的发展趋势和我国能源结构的基础上,分析了国内现有几种煤气化技术的应用现状,阐述了shell煤气化技术的特点,将该工艺与德士古水煤浆气化、鲁奇加压煤气化、间歇煤气化技术在工艺性能和工艺配置方面进行了对比。通过shell煤气化技术在湖北双环化工集团的设计实践和应用效果,论述了该技术在中国的应用前景。

Shell煤气化装置的设备及管道布置设计

Shell煤气化装置具有工艺流程复杂、自动控制要求高、气化温度和压力高、介质和管线种类繁多等特点,工程设计中设备及管道布置难度较大。笔者结合几套典型的Shell煤气化装置的工程设计实践,阐述了磨煤及干燥、煤加压及输送、煤气化、除渣湿洗、除灰、初步水处理等工序的关键设备及关键工艺管道的布置设计要点;提出了优化设备管道布置设计的建议。

Study on preparation of fast curing novolaks for the shell process

To save energy and raise molding and coremaking productivity, the synthetic procedure of novolaks for the shell process was investigated. The study indicated that it was difficult to obtain fast curing novolaks under strongly acidic conditions alone. A novel synthetic procedure was proposed for preparing novolaks in a two-step manner, a divalent metal salt catalyzed novolak preparation followed by a strong acid catalyzed novolak preparation. The optimum conditions for the two-step procedure were determined by orthogonal experiment design. The results showed that it was easy to prepare fast curing novolaks with cure time in the range of 20 s to 30 s and softening point in the range of 80℃ to 90℃ under complex catalysis conditions.

SYNTHESIS OF MBS RESIN BASED ON MOLECULE DESIGN

The relationships between the properties of PVC-MBS polyblend and of the MBS multiphase structure and between the MBS structure and polymerization parameters are studied theoretically and experimentally. MBS resin synthesized from the molecule design principle is suitable to prepare PVC-MBS polyblend with good transparency and high impact strength.

Nonlinear Analysis and Optimization of Shallow Shells of Variable Thickness

This paper is concerned with the nonlillear bending, stability and optimal design of revolution shallowshells with variable thickness. The problems are investigated by means of a modified iterative method proposedearlier by the author. Solutiolls for nonlinear bedding and stability problems of revolution shallow shells withvariable thickness, such as spherical and conical shells, are presented. Deflections and critical loads for stability arecalculated and the numerical results are plotted and given in tabular forms. It is showil that the equation determiningthe maximum deflection and the load coincides with the cusp catastrophe manifold. The optimal design of plates andshells, in Which the volullle is minimized or the critical load of shells is maximized, is investigated. When the volumeoftlle shell and the arch height of the shell are given, the variable thickness parameter can be solved. In addition, thispaper also gives tile constraint optimization of nonlinear bedding of circular plates.

无人机外壳逆向造型设计

为确保无人机有良好的气动布局和飞行稳定性,其外壳曲面均采用非规则曲面,逆向造型难度大,存在定位坐标系难确定、曲面造型质量难保证、曲面间连接效果不平滑等问题。通过三维扫描仪采集无人机外壳表面数据,形成STL模型;运用Siemens NX强大的曲面造型功能在无人机外壳STL模型的基础上进行逆向造型设计,获得了可编辑、可加工的三维模型文件;借助第三方检测软件Geomagic Control将逆向结果与原始标准模型对比验证逆向造型的精准性。Geomagic Control逆向造型结果表明所描述的曲面逆向造型设计思路基本正确,可为复杂曲面类零件的逆向造型提供可复制的经验。

SHELL规范石油化工企业事故水系统和雨水系统设计方法应用对比研究

结合某国外项目介绍了SHELL规范中石油化工厂区地下管道系统的设计内容,并着重介绍国外石油化工项目中AOC系统和CSW系统的设计计算方法,并与国内规范、企业标准中事故水系统的设计方法进行了比较。

地衣芽孢杆菌对几丁质的降解作用及其发酵工艺优化

本试验筛选到一株高效产几丁质酶的地衣芽孢杆菌(Bacillus licheniformis bl3)菌株,为了提高该菌产几丁质酶的能力,提高降解虾壳的效率,对bl3菌株的发酵条件和培养基组分配比进行了优化。结果表明,bl3产几丁质酶的最适条件为pH 4.5~5.5,温度37~45℃,转速120 r·min^(-1),接种量0.40%,酶活性最高时间为36 h。通过Plackett-Burman设计试验、最陡爬坡试验和响应面试验,得到bl3产几丁质酶的最优培养基配方为虾壳11.406 g·L^(-1),KH_(2)PO_(4)0.601 g·L^(-1),MgSO_(4)·7H_(2)O0.263 g·L^(-1),酵母粉3.500 g·L^(-1),FeSO_(4)·2H_(2)O 15.00 mg·L^(-1),ZnSO_(4)0.750 mg·L^(-1)。优化后bl3发酵产几丁质酶活性达98.122 U·mL^(-1),相较于初始培养条件提高2.43倍。优化组合培养基中的虾壳、KH_(2)PO_(4)和MgSO_(4)·7H_(2)O含量以及维持稳定pH,可促进地衣芽孢杆菌持续生长和高效合成几丁质酶量。研究结果可为bl3菌株在降解几丁质方面的应用提供科学依据。

一种剃须刀外壳注塑模具设计

以一种剃须刀外壳的设计为基础,通过分析产品结构特征,设计了一模两腔,动、定模多个斜向复杂抽芯的结构,并运用模流分析软件模拟产品的填充、保压、冷却过程。发现该模具结构设计合理,开合模动作准确可靠,多个斜向抽芯之间无干涉,产品成型表面质量较好,可以达到客户的需求。模具结构新颖,可以为同类设计提供借鉴。

深海无人系统大长径比环肋圆柱壳结构设计与试验研究

环肋圆柱壳是深海无人系统广泛采用的一种耐压结构形式,保障其结构安全是系统研制过程中非常重要的一环。针对环肋圆柱壳的结构特征推导了组合结构重量关系式和结构参数简化估算方法,并以一种超长型深海无人系统耐压结构为例,围绕大长径比环肋圆柱壳的结构形式、设计计算、仿真分析、模型验证等开展研究。研究表明提出的大长径比环肋圆柱壳结构设计参数简化估算方法具有较好的适应性。相关计算和分析结果可以为该型深海无人系统结构设计提供技术支撑,也可以为其他类似耐压结构设计提供参考。

基于等几何法和模拟退火的复杂壳结构分析及优化

本文提出了一种基于等几何法和模拟退火的壳结构分析及优化算法,旨在提高复杂壳结构的CAD与CAE一体化设计效率。首先基于NURBS技术对薄壳结构进行适分析参数化建模,然后基于Kirchhoff-Love壳理论实现等几何分析。接着,基于模拟退火算法以壳体的几何参数为设计变量,以多项力学性能为目标函数进行优化,实现了等几何分析与智能优化算法相结合的壳结构分析与优化。最后,通过2个算例验证了该算法的有效性。相对于传统有限元方法,该算法具有高精度、高效率的优势。

脱壳间隙自由可调式花生脱壳装置设计与试验

针对现有脱壳间隙不可自由调节、机械损伤率高、花生品种适应性差等问题,设计了一款脱壳间隙自由可调式花生脱壳装置。脱壳装置上部采用导杆、导套、压缩弹簧等构成脱壳间隙自由可调揉搓摆臂,下部固定有编织筛网,上下装置组成的弧形腔室构成脱壳室;揉搓摆臂驱动装置由可调速电机带动曲柄摇杆机构进行往复揉搓运动。其中,为验证间隙自由可调揉搓摆臂运行可靠平稳性,对其需满足的设计要求进行验算,确定了当弹性装置高径比为3.7和弹簧许用安全系数为2.6时,满足作业要求;对曲柄摇杆机构的设计参数和脱壳运动状态进行运动学和脱壳力学分析研究,确定了当摇杆与竖直方向夹角为40°和弹簧压缩行程为12 mm时,弹簧装置可承受最大载荷为710 N,能够满足往复揉搓运动学和脱壳力学性能要求。最后以对该装置脱壳性能影响较大的可调速电机转速为试验因素,以豫花22为试验对象,进行脱壳性能试验。试验结果表明:当电机转速为1600 r·min^(-1)时,脱净率为98.6%,破损率为2.4%,发芽率为98.8%,满足行业花生脱壳质量要求。