大厚度复合材料曲面典型构件的工艺优化

大厚度复合材料的数值仿真存在缺乏实尺度验证、数值模型待优化等问题。本文针对真空辅助树脂传递模塑成型的大厚度复合材料曲面构件,通过大型风电叶片主梁的工艺仿真与实尺度实验验证,进行了工艺设计与工艺参数模型预测。首先对比研究了不同的工艺仿真方案;然后利用所选优化方案对树脂灌注方案进行工艺设计,并进行了实验验证;最后,提出了不同厚度制件的工艺参数预测模型。结果表明:所选优化方案可同时得到理想的计算效率和流动模拟结果;所设计工艺方案与实验吻合性良好;工艺参数预测模型所得结果与模拟结果基本一致。      

双孔壳体正反挤压成形工艺

目的设计双孔壳体成形工艺方案,生产出合格产品。方法运用数值仿真方法,模拟双孔壳体成形过程,分析其成形趋势、应变图和应力图等,为工艺设计提供理论支撑。结果通过模拟仿真计算,优化和验证了双孔壳体挤压工艺方案的可行性和合理性。结论通过工艺方案分析、有限元模拟计算,确定了双孔壳体最终成形方案,并且制作出了合格的产品。     

谈三维虚拟软件高层钢结构建筑安装预演示技术

通过PKPM三维现场施工平面设计软件,对钢结构工程项目施工现场进行立体化设计布置,优化施工现场布置方案;运用Solidworks三维建模软件,建立钢构件三维数字化立体模型,并对钢结构进行安装仿真模拟,将重要施工过程进行预演示,以便及时发现问题,在施工前形成钢结构立体施工安装方案。     

废旧冰箱回收工厂设施布置设计的研究

分析了废旧冰箱回收处理现状,建立了废旧冰箱回收工艺路线,介绍了废旧冰箱回收工厂设施布置设计的一般方法和过程．采用系统布置法（sip）对废旧冰箱回收工厂总平面布置和车间布置进行了设计;利用时间Petri网对车间物流系统建模并给予优化,得出回收工厂详细布置图,并用E—Factory对该回收厂三维仿真．     

基于Plant Simulation的航空综合机加厂房布局仿真研究

科学的生产设置布局规划对航空制造业降低生产成本、提高产品质量尤为重要.以某民用航空发动机传动系统的齿轮和机匣综合加工厂房的规划设计为例,根据厂房设施布置的一般原则,以齿轮和机匣的年产量目标、产品加工工艺、单工艺加工面积需求为设计输入,并考虑各加工区的加工特点而带来的位置约束性,采用遗传算法与模拟退火算法相结合的混合遗传算法为优化工具,将特定的功能区固化在基因串特定的位置上来满足位置约束．计算得出优化方案后,以Plant Simulation为仿真平台,建立该综合机加厂房的仿真模型,从产量满足率、设备利用率、在制品库存量和生产线稳健性等多个指标进行了设施布局的仿真评价．结果表明,优化后的系统能够很好满足生产纲领,各关键设备负载比较均衡,同时维持低水平的在制品库存量,且生产线稳健性较好．因此,综合运用混合遗传算法与Plant Simulation仿真可以为生产设施布局问题给出一种有效、直观的解决方案,且由离散事件仿真获取的评价指标能深刻体现方案的优劣．     

车间设施优化布置方案

运用系统布置设计SLP方法对企业现有设施布置进行系统分析,提出优化方案,并对方案进行评价,达到降低物流成本的目的.在对某企业详细调研的基础上,对该企业某车间的物流瓶颈成功运用了该方法.     

往复压缩机管线的阻尼减振应用

针对石家庄某炼化企业往复氢气压缩机管线振动问题,研究管道系统的阻尼减振技术。现场测量管线的振动与空间布置参数,运用有限元分析软件进行模态计算与阻尼减振模拟仿真,并结合管道系统的实际振动情况,分析出管线振动的原因。根据振动成因分析及模拟仿真结果,设计出合理的阻尼减振方案。在不改变原有管线结构、压缩机不停机的情况下,安装阻尼器于管线的指定位置,有效地减小振动管线各处的振幅至安全范围内,消除了管线振动产生的安全隐患,保障生产长周期安全进行。     

基于SolidWorks 96 孔薄膜热封板温度场模拟与优化设计

针对生化分析领域96 孔样品池薄膜热封的热封板温度场分布问题,运用SolidWorks 三维软件进行建模,并运用插件Simulation 对其施行有限元分析和优化设计。首先,对现有的薄膜热封板进行了建模仿真分析,其次经过实验验证,得出模拟数据与实测数据吻合,说明该模拟仿真的思路和方法适合于优化此类非等温平板的传热问题的。最后通过对热封板中的电热丝不同排布及不同排布方式中电热丝绕行间距的调整,使得优化设计方案达到热板表面最大温差在±1 ℃以内。     

典型夹芯结构复合材料VARI工艺成型仿真计算研究

对于大尺寸夹芯结构或复杂形状夹芯结构复合材料的VARI工艺成型过程的模拟仿真计算,如果采用传统的建模方法,则建模困难,模拟仿真计算量大,效率不高。针对此问题,提出了一种简单方便的等效建模法。以弧形和带加强筋的夹芯结构复合材料构件为基础模型,采用等效建模法建立了实体CAD模型和有限元网格模型,并利用PAM-RTM软件对两种夹芯结构复合材料构件的VARI工艺成型过程进行了仿真计算,并结合工艺成型实验进行了实验验证。     

大型立柱铸造工艺设计及模拟理论

主要研究大型立柱铸造过程的数值模拟仿真及工艺优化。计算机数值模拟作为新兴产业主要针对中小铸件进行模拟仿真,但对于大型立柱铸件的数值模拟经验极少,大型立柱铸造过程的数值模拟仿真及工艺优化对于凭经验浇注为主的大型铸件铸造具有科学理论指导意义。     

Design based failure analysis and yield improvement in CMOS-circuits

In this paper we show that defect simulation is a basis for yield enhancement strategies. These strategies involve identification of the yield detractors (i.e. identification of spot defect characteristics) and yield oriented layout design, which uses information about defects. Information about key yield detractors can be obtained in a time and cost efficient manner using defect simulation. By comparison of process variants and of SRAMs with different layouts, the sensitivity of the method for process changes as well as for design differences is illustrated. This leads to the conclusion that the defect and yield simulation tools can be used for yield oriented design. The enormous cost and time savings demonstrated in this work give a signal to enforce the introduction of design based failure simulation methods into the yield learning process.     

某移动通信综合大楼空调冷源优化方案分析

针对综合楼普遍存在的空调冷源装机容量偏大的情况,为节能及减少初投资,依据现有建筑平面布置、建筑热工性能和本建筑物使用特点,采用计算模拟软件对空调冷源的装机容量和空调运行能耗进行计算和模拟;根据计算模拟结果,提出空调冷源系统的优化方案,以达到减少初投资、提高冷源运行效率的目的。     

Facility layout optimization using simulation and genetic algorithms

Traditionally, the objective of a facility layout problem has been to minimize the material handling cost of the manufacturing system. While it is important to reduce the amount of material handling, the traditional methods do not address the actual time at which the material is transported. In today's short cycle time production environments, the timing of material movement may have a bigger impact on the productivity of the system than its cost. In this paper, a facility layout optimization technique is presented that takes into consideration the dynamic characteristics and operational constraints of the system as a whole, and is able to solve the facility layout design problem based on a system's performance measures, such as the cycle time and productivity. Each layout solution is presented in the form of a string that is suitable for analysis by a genetic algorithm technique. These solutions are then translated into simulation models by a specially designed automated simulation model generator. Genetic algorithms are used to optimize the layout for manufacturing effectiveness while simulation serves as a system performance evaluation tool. Combined with a statistical comparison technique to reduce the simulation burden, the test results demonstrate that the proposed approach overcomes the limitations of traditional layout optimization methods and is capable of finding optimal or near optimal solutions.     

Development of an extended thermo-hydraulic simulation tool for fusion magnet design study - Application to the initial versions of JT-60SA TF coils layout

In the framework of the EU participation to JT-60SA project [1], a dedicated simulation tool named after Thermo-hydraulic EXtended Tool (TEXTO) was developed at CEA between 2006 and 2007 in order to address in a reliable way the calculation of the magnet conductor temperature increase and temperature margins in different operating conditions. The simulation process is based on three different codes, addressing each specific aspects (MCNP for the 3D nuclear heat calculation, TRAPS for magnetic field, ANSYS for 2D transverse thermal contribution of coil casing), which finally stand as input for the well established code GANDALF (with transient helium properties).Both steady-state operating and disruption transient regimes can be studied with this process and a first application is performed on the basis of the design and operating conditions available at this time on JT-60SA TF magnets, i.e. the first version of the different design stages. The complete analysis is shown together with the associated proposals for the TF conductor layout that could be derived from these studies.     

A Monte Carlo simulation based heuristic procedure for solving dynamic line layout problems for facilities using conventional material handling devices

A simple procedure is proposed to identify line layout solutions when a production facility with work centres of unequal size uses conventional material handling devices and operates under stochastic demand scenarios. The procedure uses Monte Carlo simulation (MCS) to empirically search for robust solutions defined as those that simultaneously meet minimum material handling cost performance levels across all demand scenarios. The results reported in this study suggest that ‘robust’ line layout solutions can be identified using a modest volume of random sampling. The procedure and results are demonstrated through a series of sample problems.     

An Integrative Model-Based Approach to Hospital Layout

The issues of facility layout and bed allocation in health care settings are typically evaluated separately using very different model-based approaches. This paper describes a two-phase approach to the hospital layout problem that incorporates a number of considerations from typical layout models and methods used in determining bed allocations. The first phase involves a quadratic integer goal programming model that determines a configuration and recommended allocation of beds to hospital services. The detailed ramifications of the proposed layout are then evaluated in the second phase via a simulation model. The application of the optimization-simulation approach in a general purpose hospital is described.     

Analysis of Clinic Layouts and Patient-Centered Procedural Innovations Using Discrete-Event Simulation

Abstract

Given that healthcare costs in the U.S. continue to climb, engineering managers can help address this situation by identifying designs for cost savings. Using discrete-event simulation, the layout of four different healthcare clinic scenarios considered in a redesign program named Patient Aligned Care Teams were studied. Model 1 is an existing layout in many clinics and Model 2 is staff-centered, while Models 3 and 4 provide additional space including common hallway(s). Our main conclusion is that Model 4 reduces patient travel distances and average queueing waits, while also providing the best privacy in accordance with HIPAA and the most security for the staff.     

Über die Auslegung und den Entwicklungsstand von Zyklon-Abscheidern

Cyclone separators are technically simple and robust devices for the separation of solid or liquid materials from fluids and widely used in industry. Their layout and design is mostly based on empirical calculation methods. However, due to the advancing computer technology numerical flow calculation methods (Computational Fluid Dynamics CFD) are increasingly applied to the design and optimization of particle separators. In the present paper, standard procedures and novel numerical flow simulation methods for the design of cyclon-separators for industrial purposes are presented and described. We discuss the pros and conts of both methods and give hints regarding the potential of numerical flow simulation for further improving the separation efficiency.     

Cost/weight optimization of composite prepreg structures for best draping strategy

The application of hand-laid carbon fiber prepreg is very expensive from a labor perspective. Therefore the manufacturing cost should be included in the design process. In this work, we propose a novel optimization framework which contains a draping simulation in combination with a detailed cost estimation package and the calculation of the structural performance based on FE. We suggest applying the methodology in two steps. First, a draping knowledge database is generated in which combinations of seed points and reference angles are evaluated in terms of fiber angle deviation, scrap, ultrasonic cuts and material shear. Second, a cost/weight optimization framework picks the best sets of plies during the subsequent optimization. The methodology is tested by means of a curved C-spar which is designed using plain weave and unidirectional prepreg. Different objectives in the generation of the draping database lead to different design solutions.     

航空发动机气动附加阻力修正测点布置与试验

通过对某型发动机的室内试车间的整场流场特性进行数值模拟研究,得到发动机试车间内的流场状况,分析了试车间内的速度、静压等物理量,绘制整场流线,针对试车间的气动附加阻力截面法修正方法,研究了在不同截面下的速度、静压变化规律,为气动附加阻力修正截面法在实际试车中的测量布点提供了依据,并且做了某型发动机室内试车台的实测试验,得到了测量及计算结果。结果表明,数值模拟可以清晰的模拟出试车时的整场状态,能得到实测不便测量部分的数据,可以对试车间不便搭建测量的位置进行补充,基于仿真得到的测点布局满足测量和计算的需求。