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Company:

福特

Products:

Adams
Easy5

Industries:

Overview:
噪声/振动/舒适性(Noise/Vibration/Harshness 简称NVH) 与燃油经济性,在车辆设计过程中,通常需要进行折中的考虑。例如,拖拽特性是一个典型工况,当汽车运行在高档位、发动机低于2000 rpm,驾驶员驱动油门踏板,发动机驱动车辆,这时产生的是相对低扭矩,所以加速度也是较低的。因为发动机工作在低速、低的点火频率和高的负载下,所以拖拽产生了较高的低频输入。驾驶员和乘客通常能感受到这些低频输入,比如座椅导轨处振动、转向盘振动和驾驶室内部的轰鸣声音。工程师控制这种拖拽,有一种主要的方法就是通过变矩器实现,即利用液力耦合器改变或者放大从发动机到变速箱的扭矩。变矩器包括一个泵,涡轮,叶轮与定子(一个充满油液的腔体,一个锁止离合器和减震器总成)。离合器是电子控制的,它提供一个理想的变化率。当需要时,离合器锁住,从而将发动机与变速器直接连接,这时传递效率是100%和最佳的燃油经济性。在锁定模式下,发动机扭矩波动直接发送到变速箱,可能导致传动系统产生振动和噪声。有渐变特性的变矩器增加了阻尼,从而降低发动机传递到传动系统振动的灵敏度,改善NVH性能。但是从另外一方面考虑,渐变特性由于有液力耦合和离合器的摩擦,降低了效率,增加了油耗。
Challenge:

挑战

 

在开发新车型时通常会遇到一系列的,通常又是相互矛盾的特性设计。燃油经济性与NVH特性是 2 个最重要的设计目标值。考虑到拖拽特性,NVH工程师们通常控制变速箱传递到传动轴振动的幅值,低于一定的目标值。NVH团队往往喜欢较大的变化率去达到设计目标,而当他们又需要考虑燃油经济性的时候,则又希望这个变化率尽可能的低。在没有原型车和测试车时,想要得到高精度的扭转振动振幅是不可能的,然而开发阶段的后期,设计被结,再想去优化性能,就会变得十分昂贵,或者可能导致生产延误。福特正在寻求一种方法去模拟不同的变矩器的影响,从而使工程师在设计和开发阶段,能更合理的匹配性能。

Solution:

方案/验证

 

福特的工程师们解决了这个难题, 方法是利用MSC软件Adams新功能,其 支持功能模块接口(Functional Mock- Up Interface 简称FMI),是一个开放的标 准工具,利用这个工具可以进行数据交 换和联合仿真。FMI标准,可以从一组 模型的物理规律和数字控制系统创建一 个虚拟产品。一个FMI构成的模型称为 功能模块单元( Functional Mock-Up Unit,简称FMU)。一个FMU文件包含一 个用XML格式描述的文件、动态链接库和模型数据库文件。FMI文件FMI可用于 交换或联合仿真模型。在Adams中FMI扩 展了Adams/Controls功能, 可以与 MATLAB 和EASY5联合仿真,也可以与 其他兼容 FMI 格式的软件进行联合仿 真。在这个案例中,福特工程师们利用 Adams中3D传动系统和整车模型作为主 要部分,与 AMSim 中1D控制器斜率控 制模型一起,把斜率变化率当做优化目 标,来达到整车的拖拽NVH目标,同时 实现燃油经济性最大化。传动模型是利 用Adams/Driverline建立的,包括一个汽 油涡轮增压直喷发动机(由三个悬置支持)、一个含有锁止离合的变矩器、一 个 6 速变速箱(内部有轴和变位齿轮 等)和一个前置传动系(包含差速器、 连接轴、半轴、等速副和车轮)。这个 传动系统模型是利用Adams/car嵌入到 整车模型中的。这个整车模型还包含底 盘、悬架、转向、制动和车轮系统的。 AMSim变矩器模型包含PID控制单元,控 制器在转换离合上施加一个法向的力, 力的大小是根据实际的变化率和实际变 化率之间的变化而变化的。

Results Validation:

结果

 

Mario Felice说:“我们用不同的转 速变化率带入模型中,其中转速变化率 覆盖发动机转速。仿真结果显示,变化 率在30rpm或者更低不能达到NVH设计目 标值,必须大于 40rpm 的变化率才可 以。仿真结果还显示当变化率在 40rpm的时候是一个优化的值,NVH性能 和燃油经济性能得到最好的匹配。”工 程师们进一步研究减小由离合器阻尼特 性和变矩器的变化率产生的扭转振动的 幅值。他们还比较了当转速变化率为0 rpm和40 rpm的时候,转向盘和座椅导 轨处的振动,由于通过改变变矩器的变 化率,转向盘和座椅导轨处的振动明显 下降。Felice还说:“下一步,我们会 细化变矩器的模型,建立液压系统,从 而提供更加准确的用一个时域函数表示 的预测力,我们还将计划用物理测试结 果来验证模型的有效性。然后我们还计 划,将在设计过程中充分的利用联合仿 真技术,从而使变矩器的设计在产品开 发周期的早期就可以进行优化。


 
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Company:

Litens

Products:

Adams
Marc

Industries:

Overview:
Litens 公司利用MSC公司的Marc非线性有限元软件拓展了精确模拟其扭矩调节器操作的能力,包括设计行为的研究,元件的运动及其之间相互作用,以及在动态加载状态下的研究等。通过对建议性方案的精确性能预估,仿真可节省大量的成本,不需要考虑在建模和测试样机上花费大量时间。可是对于非线性有限元分析计算必须考虑计算资源,因为它每次只分析一个元件。比如,执行一个典型仿真需要30个小时,这就限制了非线性分析在设计阶段的使用。

 
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Company:

Products:

Adams

Industries:

Challenge:
阿纳多卢五十铃的工程师们面临的挑战是对悬架进行优化设计,以便改进巴士的舒适性、操控性和安全性,同时确保悬架、底盘及车身零部件的疲劳性能。过去设计悬架时,需要组装样机,并且样机要完成单移线试验等标准试验。通过安装仪表的车辆来采集道路荷载数据,然后将这些数据作为四柱试验台上加速试验的输入值来评估单个零部件,从而对零部件的耐用性进行评估。四柱试验台由四个液压执行机构组成,每个执行机构连接在车辆的一个车轮上。通过执行机构的移动来仿真道路施加在车轮上的加速度。这种传统方法带来的问题是,组装样机并进行实物试验不仅极其耗时且成本高昂。

 
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Company:

Products:

Actran Acoustics
Actran AeroAcoustics
Actran DGM
Actran for Trimmed Body
Actran TM
Actran VI
Actran VibroAcoustics
Adams

Industries:

Overview:
MSC公司最近开发了Adams-Marc联合仿真技术,这种技术在首次让几何非线性和材料非线性的结构特性在多体动力学仿真中得到实现。任何Adams和Marc的模型的都能在联合仿真中使用,而后处理又是相对独立的。Adams得到的结果在Adams中,Marc得到的结果在Marc的后处理中,或者ComputationalEngineering International 公司 EnSight 的后处理中能同时导入Adams和Marc的结果。

 
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Company:

Products:

MSC Apex
MSC Apex Modeler
MSC Apex Structures

Industries:

Aerospace

Overview:
美国国家航空航天局(NASA)太空发射系统(SLS)将成为史上最强大的火箭,可通过猎户座飞船运载多达四人的航天员乘组探测多个深空目标。SLS 以一种可发展的架构为核心进行设计,支持从77 公吨(77 吨)到130 公吨(143 吨)的各种推力型号。SLS 的芯级高200 英尺,直径27.6 英尺,将储存供四台RS-25 发动机使用的液氢和液氧。RS-25 曾用作航天飞机的主发动机,在135 次发射任务中成功率达100%。为能在SLS 上使用,对RS-25 进行了修改,通过大量改进措施将其功率从491,000 真空推力磅提升至512,000 真空推力磅。

 
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Company:

Products:

Actran Acoustics
Actran AeroAcoustics
Actran DGM
Actran for Trimmed Body
Actran TM
Actran VI
Actran VibroAcoustics

Industries:

Heavy Equipment
Machinery

Overview:
一个主要拉美国家的噪声规定被修订到更低的水平,这促使CNH公司和其他的建筑设备制造商降低其产品的噪声排放。新规范使用一个公式基于机器的功率来确定其允许的声压级。在这种情况下,新的标准要求噪声相对于现有的设计降低大概6分贝。噪声测量基于ISO6393标准:六个麦克风分布于设备周围半球形的特定位置,在设备高怠速条件运行时测定声压级。CNH工程师进行了物理实验,以努力更好地了解噪声贡献源。工程师做了众多尝试,如开启和关闭风扇,开启和关闭液压泵,或掩盖排气来噪声以更好地了解噪声贡献源的相对重要性。这一系列分析表明风扇是头号噪声贡献源。

 
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Company:

Kiekert

Products:

Adams

Industries:

Automotive

Overview:

Kiekert公司拥有 150 多年的设计、开发及制造定制化锁系统的历史,在车门锁制造方面经验丰富。该公司的产品既有侧门锁、锁模块、后舱及发动机罩盖锁,也有用于侧门、平移门、行李箱盖的各种作动器及专业解决方案,其中最重要的是嵌入到后车门中的儿童安全座椅锁。以前,儿童安全锁啮合时,只能从外部打开后门。但在新车型上,可利用侧门锁内的小电机通过开关来电子激活或停用这种安全锁,开关通常位于司机侧的门锁开关附近。

Challenge:
侧门锁是一个复杂的系统,包括电缆、凸轮、杠杆机构、联轴节、作动器、齿轮、棘爪及锁闩。侧门锁通过激活棘爪和锁闩来锁住车门,使其绕着锁扣夹紧。锁扣为 U 形部件,固定在 C 柱上。而儿童安全锁是必须通过侧门锁实现的众多功能中的一个,它不仅能延长车辆寿命、在较大的温度范围内工作、符合噪声和振动要求,而且在出现碰撞时能够保持车锁的完整性。 过去,Kiekert的工程师采用运动学分析和工程手册公式等手工方法来进行侧门锁机构的初步设计。由于未能考虑到机构的动态特性,并且手册公式无法处理机构的具体几何结构,运动学分析的作用有限。因此,初期的机构设计操作通常无法满足设计要求。工程师完成初步设计并进行试验,然后根据试验结果进行反复设计,并制作出新样机。每一轮样机制作的高昂费用和冗长的研制周期都会增加设计新锁的时间和成本。采用这种设计及试验方法,设计一个锁机构需要 6 到 18个月。
Solution:
在 Adams 里可以定义机构的各种参数,以齿轮为例,可选择齿轮类型、位置、传动比、材料及连接方式。为加速锁的研发过程,Kiekert最近应用了虚拟样机技术,其关键特征是这种虚拟验证过程可以准确地仿真机构的性能,其中包括运动学和动态特性,同时还能考虑到机构的整体几何结构。Kiekert公司的仿真工程师 Darius Schendzielorz 首先将Catia中的原始设计模型导入到 Adams 中进行仿真,并通过输入参数定义儿童锁中的齿轮、轴承及电机。例如,他通过选择齿轮类型、位置、传动比、材料、连接方式及其它参数对机构中的齿轮进行了定义。对塑料杆的性能进行准确建模是至关重要的。借助最新的Adams功能,Darius Schendzielorz 在 Adams View 中通过实体创建柔性体,为前面提及的杆创建了模态中性文件(MNF)。模态中性文件包含惯性矩阵、模态振型及模态频率等信息。 然后,仿真与有限元分析项目工程师 Stelian Borlodan 在整个设计条件范围内对儿童安全锁机构的性能进行了仿真。对不同温度下的性能、假设碰撞中的载荷以及制造偏差对机构性能的可能影响进行了全面的评估。通过仿真来确定用于驱动儿童安全锁机构的电机规格,利用动画来帮助诊断与机构有关的问题,帮助工程师通过重新设计找到满足全部要求的设计。
Results Validation:
通过采用多体动力学仿真技术,Kiekert将设计儿童安全锁机构所需的时间大幅缩短到3星期左右,这意味着新型锁在 18 个月内就可以面市。

 
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Company:

TLG Aerospace, LLC

Products:

MSC Apex

Industries:

Aerospace


 
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Company:

TürkTraktör/Bias Engineering

Products:

Adams Machinery

Industries:

Automotive


 
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Company:

Omni-Lite Industries

Products:

Simufact
Simufact Forming

Industries:

Machinery

Overview:

Omni-Lite Industries is an advanced materials company. They recently designed a new part that was exhibiting a unique material flow. The part was cold formed out of 1100 aluminum material. The manufacturing process for this new part utilized a three-die progression, and was produced on a Nakashimada TH3-6A cold forming machine.

Results Validation:

Omni-Lite found that there is a very accurate correlation between the software prediction of material flow and the real-world results from the heading tooling. The results prove that simulation is a very necessary tool to use for cold forming tool design in order to reduce development cost and product development lead time.

Benefits:
  • Reduce product development costs
  • Reduce time to market by eliminating need for repetitive physical testing
  • Very close correlation between physical test results and Simufact simulation results

 
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Company:

Omni-Lite Industries

Products:

Simufact
Simufact Forming

Industries:

Machinery

Overview:

Omni-Lite is a rapidly growing advanced materials company that develops and manufactures precision components utilized by several Fortune 500 companies including Boeing, Airbus, Alcoa, Ford, Caterpillar, Borg Warner, Chrysler, and the US Military, Nike, and Adidas. To aid in its aggressive product development process, the engineering team began using the sophisticated finite element forging simulation software package Simufact.forming, from MSC Software.

Results Validation:

It was found that Simufact.forming provides invaluable information at a critical time in the design process. The software provides the opportunity to see how design variations will work out prior to purchasing any tooling. It allows Omni-Lite to shorten its process development time considerably, and respond faster to customer requirements and design new products faster.

Benefits:
  • Optimize manufacturing process to reduce development time
  • Ability to respond more quickly to changing customer requirements
  • Accelerated innovation due to faster design process

 
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Company:

DEMA SpA

Products:

MSC Apex

Industries:

Aerospace

Overview:

DEMA SpA is a major aerospace supplier that provides work packages for many major aircraft programs such as the Boeing 787, Airbus A380 and A321, ATR 42-72, Augusta Westland AW139, and Bombardier CS100. DEMA recently designed and built an innovative avionics bay pressurized door for a commuter jet. DEMA engineers developed an innovative design concept in which the door is assembled from sheet metal using a machinable plate that saves weight by eliminating the need for mechanical joints. DEMA needed to analyze the ability of the door to meet in-flight structural requirements in spite of multiple damage scenarios that might be incurred during service operations or could result from manufacturing variation in order to determine whether or not the structure maintains a sufficient safety margin. These damage scenario analyses are used as the basis for inspection protocols that are performed on a regular basis to ensure that the door is flight-ready.

Results Validation:

“Editing the geometry for one scenario took only 4 hours, a 75% reduction from the traditional method,” said Antonio Miraglia, Stress Lead for DEMA. “Prepping the model took four hours, the same as the traditional method. A total of 8 hours were thus required to model each scenario and 32 hours were required for all four scenarios, a 60% reduction from the time required in the past.”

Benefits:
  • Process of constructing 4 damage scenarios reduced from 80 hours to 32 hours
  • Time to modify geometry reduced by 75%
  • Solver validation further reduces the process from 80 hours to 26 hours

 
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Company:

TECHDYN Engineering

Products:

Marc

Industries:

Consumer Products
Energy

Overview:

In a wide range of industrial and defense applications, materials are required to perform at extreme operating conditions involving large plastic deformation, high strain rates, elevated temperatures and severe dynamic pressure. For example, materials used in armor and antiarmor technology experience deformations of 500% and higher, strain rates up to 106 per second, temperatures above the material’s melting point and pressure of several gigapascals (GPa). Likewise, in industrial applications such as forging, hot rolling, extrusion, wire drawing and sheet metal forming, workpieces undergo plastic deformations ranging up to 100%, temperatures from 500oC to 800oC, strain rates up to 100 per second and pressures up to several hundred Megapascals (MPa). Other examples of applications where high deformations, temperatures, strain rates and pressures are experienced include perforating guns in the oil and gas industry, debris impact in aerospace engineering and ship collisions in naval engineering.

Results Validation:

Now that TECHDYN has validated their material model and ability to simulate extreme conditions, the company is preparing to offer engineering consulting services using Marc with the new material model to provide accurate simulations of extreme conditions. “The ability to accurately simulate extreme conditions will help improve product performance by making it practical to evaluate many more design alternatives than would be practical using the build and test method while at the same time reducing product development cost and leadtime,” Bonora said.

Benefits:
  • Reduce physical tests
  • Improve accuracy of material behavior prediction
  • Improve product performance

 
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Company:

Boiler Structure

Products:

MSC Apex
MSC Nastran

Industries:

Energy

Overview:

Power plant sites consists of numerous built up structures, each of which must be designed for positive margins of safety. Finite Element Analysis (FEA) is a common numerical method used for determining and improving the strength and dynamic performance of such structures. With an increasing need to find optimal power plant structural designs, the most efficient FEA workflows are critical. This case study discusses methods to expedite the FEA process, namely: rapid construction of Finite Element meshes from geometry and leveraging FEA technology to quickly connect hundreds of structural members.

Challenge:

Most industrial structures consists of hundreds of structural members, many of which have the common trait of being thin-walled. This boiler structure, part of a large power plant, is an example that is characterized by thin-walled members. Finite Element Analysis (FEA) is a common method used for strength analysis, but the large size of this structure presents a number of challenges that can delay FEA. The first challenge involves constructing the finite element model, and traditionally requires hours of work. The second challenge is adjoining numerous structural members together, but the process should be both rapid and without error. The use of MSC Apex for mesh construction and the use of MSC Nastran for analysis is demonstrated.

Benefits:
  • MSC Apex accelerates the creation of midsurface geometry and FEM model
  • MSC Nastran Glue Technology is leveraged to perform strength analysis on highly an interconnected structure

 
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Company:

TürkTraktör/Bias Engineering

Products:

Adams

Industries:

Heavy Equipment
Machinery

Overview:

With annual production of 50,000 tractors, TürkTraktör is the largest producer of tractors in Turkey. The powertrains of the company’s tractors contain many gear pairs and gear groups that transmit torque through the system. For example, the transmission group includes spur and helical gear pairs. Next the torque is transmitted to the differential via a hypoid gear pair. After the differential, a planetary gear group reduces the torque. The torque is transmitted through shafts between gear pairs and most of the shafts are fastened with multiple bearings to the chassis.

Results Validation:

With the simulation model validated, TürkTraktör engineers will begin using it as part of the design process. “We are planning to use simulation in future development projects to minimize lead time and cost,” Akce said. “We have concluded that we can accurately predict the results of a testing campaign that takes several months with only two weeks of simulation. The faster speed and lower cost of simulation will also give us the ability to evaluate more design alternatives than was possible in the past. This will make it possible to reduce the weight and cost of some parts and to increase the durability of others. Of course, the design will be subjected to durability testing as a final validation step.”

Benefits:
  • Accurately predict the results of a testing campaign that takes several months with only two weeks of simulation
  • Faster speed and lower cost of simulation will also give them the ability to evaluate more design alternatives than was possible in the past
  • Adams Machinery Gear module was leveraged to quickly and easily model the gear pairs in the driveline system
  • Bearing was conveniently generated using the Adams Machinery bearing library by referencing the product code

 
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