复合材料铺层角度对大展弦比机翼非线性气动弹性影响研究

为了减轻重量和提高升阻比,现代飞行器结构普遍采用大展弦比布局,并且轻质复合材料在飞行器结构中的使用占比也越来越高。为了研究复合材料铺层角度对大展弦比机翼纵向气动特性及非线性气动弹性的影响,首先以机翼结构的弹性变形为优化目标,以结构强度为约束条件,采用Screening方法对大展弦比复合材料机翼蒙皮的铺层角度进行优化,优化后机翼的刚度明显增强。然后基于松耦合的双向流固耦合数值计算方法,对大展弦比机翼非线性气动弹性及流场进行优化前后的数值模拟,分析了复合材料铺层角度对大展弦比机翼非线性气动弹性变形及纵向气动特性的影响。     

某电磁弹射无人机复合材料机翼结构优化设计与分析

无人机已经成为航空领域重要成员之一。在无人机初步设计阶段,为减轻其结构重量,采用复合材料设计。复合材料在比强度和比刚度以及抗振和加工制造等方面优于其他传统材料,在无人机结构中得到了广泛的应用。由于复合材料层合板在生产加工过程中具有可设计性,在复合材料中已经成为使用最多的一种结构形式。以某型号电磁弹射无人机机翼为研究对象,建立了复合材料机翼结构的有限元模型,将机翼的结构重量作为优化目标,以机翼翼尖挠度和复合材料失效因子为约束条件,应用工程优化软件对复合材料翼面结构进行自由尺寸优化,整个优化过程需同时满足机翼强度及刚度要求。最终自由尺寸优化结果表明,复合材料的铺层比例和厚度分布在优化后得到了重新设计,比较之前的结构方案,优化后的铺层设计能够有效降低机翼结构质量,实现减重的优化目标。     

碳纤维复合薄壁材料的无人机机翼结构优化设计

无人机机翼结构铺层优化设计可减轻结构质量,为提升无人机机翼结构强度和降低无人机机翼结构质量,设计碳纤维复合薄壁材料的无人机机翼结构铺层优化方法。采用碳纤维T700、环氧树脂5208及Nomex蜂窝夹层优化设计碳纤维复合薄壁材料,以提升复合薄壁材料的强度。将无人机机翼结构模型内无人机机翼结构与参数作为输入,使用遗传寻优算法对无人机机翼铺层顺序实施基因编码,设置其应变约束、变形约束和稳定性约束条件。建立无人机机翼结构铺层优化铺层厚度优化数学模型和铺层层数适应度函数,并依据其约束条件对其实施求解,以实现碳纤维复合薄壁材料的无人机机翼结构铺层优化。结果表明：该方法可有效优化碳纤维复合薄壁材料的无人机机翼结构铺层厚度和层数,并提升无人机机翼结构的强度。     

某无人机复合材料主翼盒准等强度设计与有限元分析

以某无人机复合材料主翼盒准等强度设计与优化为目标,研究了主翼盒基于载荷分段的包络设计方法与铺层优化方法。采用等步长载荷包络设计方法计算了准等强度翼盒前梁的分布载荷,给出了前、后梁的初步铺层设计。建立了主翼盒的有限元模型,基于有限元分析结果校核了主翼盒的强度、刚度和稳定性。给出了主翼盒前、后梁以及蒙皮的铺层优化方案。研究结果表明,等步长载荷包络设计方法能够方便地计算主翼盒前、后梁的分段载荷;基于经典层合板理论对主翼盒进行铺层的初步设计,并运用有限元软件进行分析与校核,可以快速、有效地完成主翼盒铺层的分段优化设计;大展弦比机翼受最大正过载时,翼根上表面受压缩载荷,前梁上缘条和上蒙皮易发生局部屈曲失稳;减少主翼盒前、后梁下缘条以及下蒙皮铺层数目,可使结构减重达5.23%。     

民机复材机翼主结构优化设计及减重分析

在同一输入条件下,采用两级序列优化方法,基于同一假想飞机的机翼机身有限元模型,在相同的外形输入和载荷工况、以及不同的约束条件下,采用了基于敏度的优化方法,嵌入集成了工程校核方法,以重量最轻为目标进行了金属构型和复材构型两种机翼翼盒主结构的优化设计和分析,优化过程中考虑了长桁蒙皮刚度比例、各剖面EI/GJ刚度、制造限制等约束条件。优化结果分析表明:基于自然网格模型的高精度分析、嵌入式并行校核和多工况、多专业约束优化条件下所给出的设计结果更符合工程实际应用要求;对同一假想飞机翼盒主结构,复材构型比金属构型实现减重约15%。     

飞艇吊舱的综合优化设计

通过对飞艇吊舱外挂结构特性的分析,以吊舱重量轻和制造成本低为设计目标,在对材料选取、结构布局和结构细节设计等方面进行综合优化设计。并通过有限元分析和静力试验对优化后的舱体结构进行静强度、刚度验证。计算及试验结果表明飞艇吊舱满足强度、刚度设计要求,结构重量比予定重量节省10%,从而可以增加有效任务载荷或减少浮囊体积。     

变形机翼前缘柔性蒙皮优化设计与分析

绿色航空要求下一代飞机结构能够实现光滑连续的变形,以保证全包线下的飞行性能最优。现有变形结构方案难以平衡变形精度和承载的矛盾,且变形精度难以满足层流机翼飞行的要求。为了有效地解决该矛盾,本文针对CAE-AVM远程公务机提出了一种无缝光滑的变弯度机翼前缘结构方案及柔性蒙皮优化设计方法。该结构主要由复合材料柔性蒙皮和内部连杆机构组成。在优化方法中,本文提出了加权最小平方差(WLSE)的变形控制优化问题目标函数,进行变形误差的描述,采用NSGA-Ⅱ的智能优化算法实现了对复合材料铺层、连接点位置和驱动力大小等设计变量的协同优化,并分析了实现的最终外形与目标外形的变形误差,获得了变弯度机翼前缘复合材料柔性蒙皮的最优刚度分布。     

基于粒子群优化算法的板翅式换热器优化设计

以板翅式换热器的质量作为目标函数,以换热器芯体外形尺寸和翅片参数作为优化变量,采用粒子群优化算法对其结构尺寸进行优化设计,获得了换热器质量减轻、体积减小的效果。     

洗衣机波轮有限元分析及拓扑优化设计

为提高波轮结构设计与开发效率，提升波轮洗涤质量，降低波轮材料损耗，针对波轮结构的优化设计，运用有限元分析和拓扑优化的方法，并以某迷你洗衣机波轮为例进行实例验证。首先，对波轮结构进行优化设计，并以此为基础进行后续分析与优化；其次，用Solid Works软件建立波轮三维模型并导入Ansys Workbench软件，进行静力学分析和模态分析，得到典型工况下的变形、应力和固有频率情况，由此确定其结构优化设计的方向；最后，在保证波轮强度和刚度的情况下，以优化波轮质量为目标，通过拓扑优化方法对波轮进行结构分析与改进，并进行对比验证。对比结果表明，优化后的波轮结构在提高强度和刚度的同时，波轮整体质量减轻了18%，优化设计效果明显。本研究为实际产品的结构优化设计提供了方法和依据。     

基于理想点法的汽车仪表台骨架多目标拓扑优化

以某国产车仪表台骨架为例,应用Hyperworks软件建立了仪表台骨架有限元分析模型,并对仪表台骨架进行了点刚度、总刚度以及模态分析。为优化仪表台骨架的刚度以及固有频率,将多目标拓扑优化设计技术引入汽车仪表台骨架的结构设计中,应用理想点法建立汽车仪表台骨架多目标拓扑优化数学模型,其中点刚度拓扑优化目标函数采用极大极小法定义。通过多目标拓扑优化技术得到了理想的壁厚分布云图,根据壁厚分布云图,同时考虑生产加工条件,采用局部区域壁厚渐变的方式对仪表台骨架进行结构优化设计,并对优化后的仪表台骨架重新进行点刚度、总刚度以及模态分析,结果表明:采用多目标拓扑优化后,仪表台骨架的刚度和模态频率明显提升,改善了仪表台骨架的性能。     

化工过程模拟优化的演变优化方法

研究了化工过程模拟优化的一类新方法——过程演变优化方法,提出基于ＤＮＮ（动态人工神经网络）的动态算法的统一框架,阐明其并行分布计算特性,并给出一些基于过程规划的计算动力学模型。     

裂解原料的优化

通过分析扬子石化裂解原料结构和裂解性能,优化裂解原料配置,实施原油分贮分炼,提高自产石脑油品质和轻质裂解原料比例,同时利用石脑油吸附分离技术,进一步改善石脑油品质,提高乙烯收率。     

A NEW SIMULATING OPTIMIZATION APPROACH COMPUTER-AIDED OPERATING OPTIMIZATION FOR EXISTING CHEMICAL PROCESSES

In applying computation technique to improve the operation of existing chemical processes,a computer-aided process optimization method is proposed——the improved two-tier method based on SuccessiveQuadratic Programming(SQP).By inserting extra variables in SQP,a new quadratic programming prob-lem is constructed,and a decomposition strategy for the quadratic programming is also pressented,whichhas been found to be always feasible when the matrix is singular.This new two-tire method based onSQP has better performance both in numerical stability and in convergence behavior.Satisfactory resultis obtained in applying this algorithm to optimize a methanol synthesis process,thus leading to implemen-tation in actual practice.     

OPTIMIZATION OF SURGE CAPACITY

Surge tanks within a process are often necessary to smooth out fluctuations in plant operation and process upsets. The only previous research done on tank sizing for flow smoothing was done by Hiester (1985). In this reseach, a program is developed that specifies the size and location of surge capacity required for different control schemes of chemical processes. Also, an advanced level control algorithm is compared to conventional controllers in terms of required surge volume.     

快装锅炉的优化控制

联锁报警保护系统是快装锅炉正常运行的关键,通过对快装锅炉和主控室部分的改造,提高了系统可靠性,保证了装置运行的安全性和稳定性,使新系统满足了安全生产的需求,     

优化动力配煤

简述优化动力配煤的工艺流程，指出配煤的种类配比，燃烧性和结渣性，通过优化配比，总结出动力煤技术是值得推广的，经济实用和洁净煤技术。     

MOLECULAR MODELING FOR PLANT-WIDE OPTIMIZATION

In this article, molecular modeling of process streams and processes is combined with overall refinery optimization to select feedstocks and products, optimize the operation of different processes, and determine the most economic modifications. The molecular compositions of the hydrocarbon mixture are described using a MTHS (Molecular Type Homologous Series) matrix. To model reaction processes, structure-reactivity correlations are developed by regressing a wide range of pilot plant and commercial data. Molecular level kinetics is combined with current reactor modeling techniques. To integrate molecular modeling with plant-wide optimization, the interface between molecular compositions and bulk properties is also developed. The plant-wide optimization consists of a two-level optimization procedure, namely the site level and process level. The site level optimization addresses the overall trade-offs among the selections of feedstocks, products, processes, and the use of utilities. The process level optimization optimizes the individual processes by adjusting the detailed operating parameters. With the detailed molecular information available from the molecular model, it is possible to distinguish the contributions from different feedstocks and optimize the operation conditions to produce the most desirable products. A feedback mechanism is built for the coordination between these two levels. By optimizing the overall plant using molecular models, overall profit will be maximized by maximizing desired molecules to form valuable products, minimizing undesired ones, and routing all the molecules to their most appropriate destinations.     

MOLECULAR MODELING FOR PLANT-WIDE OPTIMIZATION

In this article, molecular modeling of process streams and processes is combined with overall refinery optimization to select feedstocks and products, optimize the operation of different processes, and determine the most economic modifications. The molecular compositions of the hydrocarbon mixture are described using a MTHS (Molecular Type Homologous Series) matrix. To model reaction processes, structure-reactivity correlations are developed by regressing a wide range of pilot plant and commercial data. Molecular level kinetics is combined with current reactor modeling techniques. To integrate molecular modeling with plant-wide optimization, the interface between molecular compositions and bulk properties is also developed. The plant-wide optimization consists of a two-level optimization procedure, namely the site level and process level. The site level optimization addresses the overall trade-offs among the selections of feedstocks, products, processes, and the use of utilities. The process level optimization optimizes the individual processes by adjusting the detailed operating parameters. With the detailed molecular information available from the molecular model, it is possible to distinguish the contributions from different feedstocks and optimize the operation conditions to produce the most desirable products. A feedback mechanism is built for the coordination between these two levels. By optimizing the overall plant using molecular models, overall profit will be maximized by maximizing desired molecules to form valuable products, minimizing undesired ones, and routing all the molecules to their most appropriate destinations.     

OPTIMIZATION OF PRESSURE SWING ADSORPTION EQUIPMENT PART II OPTIMIZATION OF TWO BED OXYGEN GENERATORS

Local equilibrium model described in Part I is used to stimulate both, the steady state operation conditions and transient regime after the start of PSA equipment. The effect of axial dispersion, adsorption isotherm nonlinearity and high pressure level is simulated. On the basis of numerical analysis, the operation of a classical two-bed oxygen generator is compared with two configurations having pressure equalizing step. The optimization strategy of the given PSA equipment has been proposed and the procedure is demonstrated on an example. The scaling-up condition for PSA equipments which can be described by local equilibrium model has been proposed on the basis of the theoretical analysis.     

MULTIOBJECTIVE OPTIMIZATION OF DRYING PROCESS

On the basis of multiobjective optimization the analysis of process conditions of L-lysine drying in a fluidized-bed dryer was performed. Two methods of multiobjective optimization were used: a sequential one and the method of minimal losses. Results obtained were compared with those of one-objective optimization. The multiobjective optimization methods have been found useful in the selection of drying conditions in the dryer under consideration.