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大孔径反射镜的柔性支撑在随机振动试验中应力响应较大,可能产生残余应变进而导致空间光学遥感器成像质量下降,因此,对大孔径反射镜组件进行随机振动响应分析尤为必要。阐述了随机振动分析的基本原理及其有限元实现。建立了反射镜组件的有限元模型,对其进行了随机振动响应分析,得出了反射镜的加速度均方根响应和柔性支撑的均值应力响应。分析结果表明:反射镜加速度响应均方根为16.3Grms;柔性支撑的均值应力响应为34.9MPa。随后进行了随机振动试验验证,结果表明:反射镜组件均方根加速度响应为16.0Grms;均值应力响应为30.3MPa。均方根加速度响应分析误差为1.8%,均值应力分析误差为13.2%,满足精度要求,验证了该方法的正确性。 相似文献
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Irmela Zentner Stefano TarantolaE. de Rocquigny 《Reliability Engineering & System Safety》2011,96(3):391-397
In this paper, we present an application of sensitivity analysis for design verification of nuclear turbosets. Before the acquisition of a turbogenerator, energy power operators perform independent design assessment in order to assure safe operating conditions of the new machine in its environment. Variables of interest are related to the vibration behaviour of the machine: its eigenfrequencies and dynamic sensitivity to unbalance. In the framework of design verification, epistemic uncertainties are preponderant. This lack of knowledge is due to inexistent or imprecise information about the design as well as to interaction of the rotating machinery with supporting and sub-structures. Sensitivity analysis enables the analyst to rank sources of uncertainty with respect to their importance and, possibly, to screen out insignificant sources of uncertainty. Further studies, if necessary, can then focus on predominant parameters. In particular, the constructor can be asked for detailed information only about the most significant parameters. 相似文献
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In this paper, an approach is proposed that verifies the controller logic processes for the automobile industry via simulation. For this purpose, a state-based object model that creates a virtual car body assembly line is proposed and a verification methodology using observed signal sequences during the simulation is proposed. This approach was applied to an assembly line controlled by a PLC and the effectiveness of the proposed system was explained in a case study. 相似文献
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S. Cheng K. Kupfer M. Dixon S. Shammas 《Quality and Reliability Engineering International》2019,35(1):483-502
An optimized sampling design that meets customer, design, or process requirements, while balancing technology limitations, is still a common challenge to engineering communities. This is especially true in the medical device industry. Acceptance sampling plans for manufacturing are widely available, but the appropriate sampling plans for verification and validation (V&V) are less well known. This paper applies established statistical theory to derive sampling plans appropriate for estimating product reliability during V&V, where reliability must exceed an established threshold with an appropriate margin of statistical confidence. The paper provides insight on how to estimate parameters of interest and interpret acceptance criteria. Operating characteristic curves are used to examine if a design or process is capable of producing future product that meets design specifications and/or customer requirements in terms of confidence and reliability. The methodology is applied to both attribute and variable sampling plans, including examples showing how to achieve a high probability of passing the acceptance criteria. Formulas, sample size tables, and operating characteristic curves are provided for engineering practitioners to use. The paper aims at providing a practical quantitative approach and a valid statistical rationale to assess overall product quality during V&V. 相似文献
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摘要:柔性结构振动主动控制的核心问题之一是控制策略与方法,针对FXLMS自适应滤波前馈振动控制方法参考信号不易选取问题,给出一种多通道FULMS自适应滤波前馈振动控制方法;首先进行控制器结构的分析与构建,概括描述和推导了多通道FULMS控制算法过程;为验证所分析算法的可行性和优越性,基于MATLAB软件包进行仿真分析,并与FXLMS算法分别进行单通道和多通道控制效果对比,分析结果表明多通道控制优于单通道控制,FULMS算法优于FXLMS算法。在此基础上,以航天器柔性帆板结构为理想模拟对象,构建压电机敏柔性板结构和测控系统进行实际算法控制实验;实验过程与验证结果表明,采用的FULMS控制器设计方法与控制算法是有效可行的,并具有较快的收敛速度和较好的控制效果。 相似文献
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A. K. Bhattacharjee S. D. Dhodapkar R. K. Shyamasundar 《Reliability Engineering & System Safety》2001,71(3):299-310
In this paper, we describe the design and implementation of an environment for specification, analysis and verification of reactive systems. The environment allows the user to develop specification in the graphical formalism of Statecharts and analyze them using a simulation tool. A built-in translator tool translates the specification into an Esterel program for the purpose of carrying out verification. Through such an approach, we have been able to integrate the powerful graphical formalism of Statecharts, which is very appealing to engineers, and the power of the formal verification environment of Esterel. Since we translate Statecharts, which can be non-deterministic, to Esterel programs, which are fully deterministic, the system overcomes the non-determinism in the specifications by enforcing priority. The behavior of Esterel programs generated by the translator follow Harel and Naamad's ‘step’ semantics. In the paper, we describe the main components of the PERTS environment and the principles underlying the translation and illustrate the use of the system for specification and verification using an example. 相似文献
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Safety-critical software systems such as certain nuclear instrumentation and control (NI&C) systems should be developed with thorough verification. This study presents a method of software requirement verification with a case study for a nuclear power plant (NPP) protection system. The verification introduces colored petri net (CPN) for system modeling and prototype verification system (PVS) for mathematical verification. In order to aid flow-through from modeling by CPN to mathematical proof by PVS, an information extractor from CPN models has been developed in this paper. In order to convert the extracted information to the PVS specification language, a translator has also been developed. This combined method has been applied to the functional requirements of the Wolsong NPP Shut Down System #2 (SDS2); logical properties of the requirements were verified. Through this research, guidelines and a tool support for the use of formal methods have been developed for application to NI&C software verification. 相似文献
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Experimental verification and application of a practical corrosion model for uniformly depassivated steel in concrete 总被引:1,自引:0,他引:1
A practical corrosion model for predicting the corrosion rate of uniformly depassivated steel in concrete was previously developed.
The model is built on Stern’s earlier work that an optimum anode-to-cathode ratio exists on the steel surface for which the
corrosion current reaches a maximum value. Based on this principle, analytical and numerical techniques were used to obtain
a relationship among the steel corrosion rate, concrete resistivity, the oxygen concentration on the surface of the member,
oxygen diffusion coefficient, and cover thickness. The main objective of this paper is to present an extensive experimental
verification and application of the developed model. For this purpose, three experimental programs carried out by other research
groups were selected. The first set of data was used in the verification of the model when different types of cement are used
in concrete. The second study was selected to verify the model with the measured corrosion rates obtained by different instruments
to eliminate any concerns that may originate from the corrosion measurement technique. Finally, in the last verification study,
the model’s interpretation of the effects of concrete resistivity and the oxygen concentration on the corrosion rate is verified.
In all cases, it has been demonstrated that the developed model predicts the experimental observations with reasonable accuracy. 相似文献
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The step complexity measure for emergency operating procedures: measure verification 总被引:1,自引:0,他引:1
Jinkyun Park Wondea Jung Jaejoo Ha Changkue Park 《Reliability Engineering & System Safety》2002,77(1)
In complex systems, such as nuclear power plants (NPPs) or airplane control systems, human errors play a major role in many accidents. Therefore, to prevent an occurrence of accidents or to ensure system safety, extensive effort has been made to identify significant factors that can cause human errors. According to related studies, written manuals or operating procedures are revealed as one of the most important factors, and the understandability is pointed out as one of the major reasons for procedure-related human errors.Many qualitative checklists are suggested to evaluate emergency operating procedures (EOPs) of NPPs. However, since qualitative evaluations using checklists have some drawbacks, a quantitative measure that can quantify the complexity of EOPs is very necessary to compensate for them.In order to quantify the complexity of steps included in EOPs, Park et al. suggested the step complexity (SC) measure. In addition, to ascertain the appropriateness of the SC measure, averaged step performance time data obtained from emergency training records for the loss of coolant accident and the excess steam dump event were compared with estimated SC scores. Although averaged step performance time data show good correlation with estimated SC scores, conclusions for some important issues that have to be clarified to ensure the appropriateness of the SC measure were not properly drawn because of lack of backup data.In this paper, to clarify remaining issues, additional activities to verify the appropriateness of the SC measure are performed using averaged step performance time data obtained from emergency training records. The total number of available records is 36, and training scenarios are the steam generator tube rupture and the loss of all feedwater. The number of scenarios is 18 each. From these emergency training records, averaged step performance time data for 30 steps are retrieved.As the results, the SC measure shows statistically meaningful correlation with averaged step performance time data. In addition, since it is observed that the SC measure seems to have the procedure independent property (i.e. steps that have similar SC scores, whether they are included in different procedures or not, would have similar step performance time), it can be concluded that the SC measure can represent the complexity of steps included in EOPs. 相似文献
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摘要:建立正确的电机动力学模型是分析系统稳定性和动态特性的基础。考虑到用电设备工作时的脉冲电流是发电机传动机构扭转振动的主要激励源,利用集中参数法建立了某型交流发电机的动力学模型,并在MATLAB环境下对其进行动态仿真分析,得到脉冲电流作用下弹性轴冲击扭转振动的力矩曲线与扭转角曲线。通过对仿真结果的对比分析,发现适当增大弹性轴的轴径,可以有效缓解弹性轴扭转力矩的振动峰值,并提高系统的频率裕度。最后,通过动态测试实验,验证了电机动力学模型与仿真结果的有效性。 相似文献
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Miguel Núñez-Merino Juan Manuel Maqueira-Marín José Moyano-Fuentes Pedro José Martínez-Jurado 《国际生产研究杂志》2020,58(16):5034-5061
The purpose of this paper is to provide an overview of the current state of research and the key aspects and implications of the relationships between Information and Digital Technologies (IDT) of Industry 4.0 and Lean Supply Chain Management (LSCM), with the identification of the lines of research developed and an analysis of the main findings. A Systematic Literature Review methodology has been used for the identification, selection, and evaluation of the published research. A set of 78 papers deduced from the most relevant scientific databases, including Web of Science, Scopus, and ABI/Inform, from 1996 to December 2019, has been analyzed and synthesized. The analysis and evaluation of these papers has enabled a new classification of the literature to be offered that identifies four lines of research based on the Life Cycle of Technology: obsolete IDT in LSCM; mature IDT in LSCM; emerging IDT in LSCM; and an Information Systems and IDT general approach in LSCM. The paper goes on to discuss the gaps found in the literature and proposes new opportunities and challenges for future research. A series of implications are presented intended to be useful from not only an academic point-of-view but also from a management focus, including recommendations for industrial managers and policymakers. 相似文献
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Khadijeh Arabi 《中国工程学刊》2016,39(4):493-497
Wireless sensor networks (WSNs) consist of small nodes that are capable of sensing, computing, and communication. One of the greatest challenges in WSNs is the limitation of energy resources in nodes. This limitation applies to all of the protocols and algorithms that are used in these networks. Routing protocols in these networks should be designed considering this limitation. Many papers have been published examining low energy consumption networks. One of the techniques that has been used in this context is cross-layering. In this technique, to reduce the energy consumption, layers are not independent but they are related to each other and exchange information with each other. In this paper, a cross-layer design is presented to reduce the energy consumption in WSNs. In this design, the communication between the network layer and medium access layer has been established to help the control of efforts to access the line to reduce the number of failed attempts. In order to evaluate our proposed design, we used the NS2 software for simulation. Then, we compared our method with a cross-layer design based on an Ad-hoc On-demand Distance Vector routing algorithm. Simulation results show that our proposed idea reduces energy consumption and it also improves the packet delivery ratio and decreases the end-to-end delay in WSNs. 相似文献
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通过调研中央空调系统节能改造项目相关案例,分析和归纳目前常用的中央空调系统节能改造措施及策略。重点介绍GB/T287502012规定的节能量测量和验证方法,明确不同方法在中央空调系统中的适用情况,给出不同方法的典型应用场合和应用示例。 相似文献