scholarly journals A zonal safety analysis methodology for preliminary aircraft systems and structural design

2018 ◽  
Vol 122 (1255) ◽  
pp. 1330-1351 ◽  
Author(s):  
Z. Chen ◽  
J. P. Fielding
Keyword(s):  
Failure Modes ◽  
Hazard Analysis ◽  
Fault Tree Analysis ◽  
Cost Effective ◽  
Safety Analysis ◽  
Design Tool ◽  
Assessment Process ◽  
Design Stage ◽  
Preliminary Design

ABSTRACTZonal Safety Analysis (ZSA) is a major part of the civil aircraft safety assessment process described in Aerospace Recommended Practice 4761 (ARP4761). It considers safety effects that systems/items installed in the same zone (i.e. a defined area within the aircraft body) may have on each other. Although the ZSA may be conducted at any design stage, it would be most cost-effective to do it during preliminary design, due to the greater opportunity for influence on system and structural designs and architecture. The existing ZSA methodology of ARP4761 was analysed, but it was found to be more suitable for detail design rather than preliminary design. The authors therefore developed a methodology that would be more suitable for preliminary design and named it the Preliminary Zonal Safety Analysis (PZSA). This new methodology was verified by means of the use of a case study, based on the NASA N3-X project. Several lessons were learnt from the case study, leading to refinement of the proposed method. These lessons included focusing on the positional layout of major components for the zonal safety inspection, and using the Functional Hazard Analysis (FHA)/Fault Tree Analysis (FTA) to identify system external failure modes. The resulting PZSA needs further refinement, but should prove to be a useful design tool for the preliminary design process.

Safety Analysis Model of DUCG Based on FMEA/FTA

2018 ◽  
Author(s):  
Zhenxu Zhou ◽  
Hao Nie ◽  
Chunling Dong ◽  
Qin Zhang
Keyword(s):  
Failure Modes ◽  
Fault Tree Analysis ◽  
Safety Analysis ◽  
Nuclear Industry ◽  
Analysis Model ◽  
Industrial Systems ◽  
The Past ◽  
Research Cycle ◽  
Dynamic Uncertain Causality Graph ◽  
Analytical Power

Failure Modes and Effects Analysis (FMEA) is a useful tool to find possible flaws, to reduce cost and to shorten research cycle in complex industrial systems. Fault Tree Analysis (FTA) has gained credibility over the past years, not only in nuclear industry, but also in other industries like aerospace, petrochemical, and weapon. Both FMEA and FTA are effective techniques in safety analysis, but there are still many uncertain factors in them that are not well addressed until now. This paper combines FMEA and FTA based on Dynamic Uncertain Causality Graph (DUCG) to solve this issue. Firstly, the FMEA model is mapped into a corresponding DUCG graph. Secondly, FTA model is mapped into a corresponding DUCG graph. Thirdly, combine the above DUCG graphs. Finally, users can modify the combined DUCG graph and calculations are made. This paper bridges the gap between FMEA and FTA by combining the two methods using DUCG. And additional modeling power and analytical power can be achieved with the advantages of the combined DUCG safety analysis model and its inference algorithm. This method can also promote the application of DUCG in the system reliability and safety analysis. An example is used to illustrate this method.

Evaluating Mobility Behavior of Fluid Filled Fiber-Reinforced Elastomeric Enclosures

2012 ◽  
Author(s):  
Girish Krishnan ◽  
Joshua Bishop-Moser ◽  
Charles Kim ◽  
Sridhar Kota
Keyword(s):  
Large Class ◽  
Power Density ◽  
Cost Effective ◽  
Design Tool ◽  
Preliminary Design ◽  
Fiber Reinforced ◽  
Soft Robots ◽  
Large Power ◽  
Mobility Behavior ◽  
Narrow Class

Fluid filled Fiber Reinforced Elastomeric Enclosures (FREE) have been popular choices for actuators in prosthetics and soft robots owing to their large power density and cost effective manufacturing. While a narrow class of FREEs known as McKibben’s actuators have been extensively studied, there is a wide unexplored class that could be potentially used as actuators and load bearing members. This paper analyzes the mobility of a large class of FREEs based on simple geometric relationships that originate due to the inextensibility of fibers and incompressibility of fluids. The analysis conducted on various families of fibers reveal certain configurations that are locked under fluidic actuation. Furthermore the analysis reveals unrestricted motion in certain directions (freedom) and restrictions in certain other directions (constraint). Such an analysis is deemed to be useful as a preliminary design tool to pick the appropriate geometry for use in design of soft robots and actuators.

scholarly journals Supply chain risk assessment approach for process quality risks

2017 ◽  
Vol 34 (7) ◽  
pp. 940-954 ◽  
Author(s):  
Abhijeet Ghadge ◽  
Xie Fang ◽  
Samir Dani ◽  
Jiju Antony
Keyword(s):  
Risk Assessment ◽  
Fuzzy Logic ◽  
Supply Chain ◽  
Failure Modes ◽  
Design Stage ◽  
Security Risks ◽  
Content Type ◽  
Fuzzy Logic Approach ◽  
Logic Approach

Purpose The purpose of this paper is to proactively analyse and mitigate the root causes of the product and security risks. The case study approach examines the effectiveness of the fuzzy logic approach for assessing the product and process-related failure modes within global supply chain context. Design/methodology/approach The case study of a Printed Circuit Board Company in China is used as a platform for conducting the research. Using data triangulation, the data are collected and analyzed through interviews, questionnaires, expert opinions and quantitative modelling for some interesting insights. Findings Fuzzy logic approach for failure mode and effect analysis (FMEA) provides a structured approach for understanding complex behaviour of failure modes and their associated risks for products and processes. Today’s managers should conduct robust risk assessment during the design stage to avoid product safety and security risks such as recalls. Research limitations/implications The research is based on the single case study and multiple cases from different industry sectors may provide some additional insights. Originality/value The study attempts to mitigate the root causes of product and processes using fuzzy approach to FMEA in supply chain network.

Automated Combustor Preliminary Design Using Tools of Different Fidelity

2013 ◽  
Author(s):  
Andreas Angersbach ◽  
Dieter Bestle ◽  
Ruud Eggels
Keyword(s):  
Design Process ◽  
Design Tool ◽  
Thermal Design ◽  
Design Stage ◽  
Air Distribution ◽  
Preliminary Design ◽  
Cfd Analysis ◽  
Fuel Injector ◽  
Geometry Model ◽  
3D Geometry

The design of a modern aero-engine combustor is a highly complex and multi-disciplinary task. The combustor design is strongly driven by severe emission regulations and ACARE 2020/2050 goals. Furthermore, new designs have to be developed within short turn-around times. This paper describes a novel approach of an automated preliminary aero-thermal design process of a rich-burn combustor combining 1D, 2D and 3D design tools in order to speed up the design loop and provide improved combustor designs in an early design stage. The automated design process includes a knowledge-based preliminary design tool, an 1D network solver, a parametric 3D geometry model, a meshing tool, and 3D-CFD analysis. At first, a preliminary combustor design is created based on industrial in-house design rules. The preliminary design tool provides a 2D geometry model and cooling layout. It is coupled with an 1D network solver to calculate the air distribution inside the combustor. The design process includes two state-of-the-art combustor cooling schemes, effusion cooling and impingement effusion cooling. An air flow model for both cooling schemes is created within the network, respectively. The computed air distribution is subsequently used to generate boundary conditions for a 3D-CFD analysis. To perform the CFD calculations, a parametric 3D geometry model of a combustor sector has been developed based on a 2D preliminary design which takes into account mixing port properties, fuel injector, and combustor wall cooling. After an automated meshing 3D-CFD computations are performed. As a result, quick automatic estimation of combustor emissions, size and efficiency can be obtained within the design process. A CFD parameter study of a mixing port variation and their effect on the emissions of NOx and soot is performed using the described layout process.

The Rigorous Application of FMEA to a Wastewater Treatment Plant Aerator Drive: Understanding Requirements, Conditions, Limitations, and Success Factors

2009 ◽  
Author(s):  
Tomoki Tanaka ◽  
Daniel J. Rosseljong
Keyword(s):  
Wastewater Treatment ◽  
Success Factors ◽  
Failure Modes ◽  
Treatment Plant ◽  
Fault Tree Analysis ◽  
External Factors ◽  
Treatment Facility ◽  
Top Down ◽  
Tree Analysis

Any supplied gearbox performing below a user’s clearly defined expectations can be viewed as a failure. This case study involves consistent lubricant leakage starting almost immediately after installation. Through various field inspections, modifications and a factory rebuild, the problem was not resolved to the owner’s satisfaction until replaced by (2) new units. This paper documents the factual elements of an engineering evaluation of a gearbox removed from an aerator drive at a wastewater treatment facility, using FMEA [Failure Modes and Effects Analysis] over FTA [Fault Tree Analysis]. The gearbox supplier chose FMEA because it considers the importance of the gearbox components, weighting them to the application, where FTA is often a pure top-down analytical engineering approach without consideration for external factors. The gearbox supplier performed a detailed disassembly of the gearbox under controlled conditions and inspected each gearbox component to identify any faults in material or designs focusing on those that affect the user. The goal of this analysis is to provide a technical understanding of the cause(s) of failure, its consequences, and a means to correct any problems with the gearbox, real or perceived.

scholarly journals AERODYNAMIC LOAD OF AN AIRCRAFT WITH A HIGHLY ELASTIC WING

2017 ◽  
Vol 57 (4) ◽  
pp. 272
Author(s):  
Pavel Schoř
Keyword(s):  
Navier Stokes ◽  
Design Stage ◽  
Computational Time ◽  
Aerodynamic Load ◽  
Preliminary Design ◽  
Elastic State ◽  
Preliminary Design Stage ◽  
Evaluation Stage ◽  
Load Evaluation

In this article, a method for calculation of air loads of an aircraft with an elastic wing is presented. The method can predict a redistribution of air loads when the elastic wing deforms. Unlike the traditional Euler or Navier-Stokes CFD to FEM coupling, the method uses 3D panel method as a source of aerodynamic data. This makes the calculation feasible on a typical recent workstation. Due to a short computational time and low hardware demands this method is suitable for both the preliminary design stage and the load evaluation stage. A case study is presented. The study compares a glider wing performing a pull maneuver at both rigid and and elastic state. The study indicates a significant redistribution of air load at the elastic case.

Training Related Risk Factors of Firefighters

2017 ◽  
Vol 61 (1) ◽  
pp. 1844-1847 ◽  
Author(s):  
Menekse Salar ◽  
M. Fehmi Capanoglu ◽  
Alexander Sherman ◽  
Richard F. Sesek ◽  
Jerry Davis
Keyword(s):  
Failure Modes ◽  
Hazard Analysis ◽  
Fault Tree Analysis ◽  
Fire Departments ◽  
Work Related ◽  
Experience Levels ◽  
Risk Of Injury ◽  
Related Risk ◽  
Assessment Matrix ◽  
Evacuation Plan

Firefighters have among the most physically and psychologically challenging jobs in the world, incurring more than 80,000 (NFPA, 2014) injuries each year. Firefighter training is crucial, as higher knowledge and experience levels are inversely proportional to their risk of injury or work-related illness (Gonzalez, 2002). However, a paradox is created in that the training itself is the third highest cause of firefighter injury (Burgess, 2014). Therefore, enhancing training safety is paramount to creating a safer overall work environment for firefighters. This study focuses on a particularly hazardous aspect of training; crawling. A crawling simulator used by the Opelika and Auburn Fire Departments was built into the back of a trailer and is located in Lee County, Alabama. A system safety analysis was performed incorporating the use of tools including a preliminary hazard list (PHL), preliminary hazard analysis (PHA), risk assessment matrix, fault tree analysis (FTA), and failure modes and effects analysis (FMEA). Several hazards were identified and assessed. Recommendations for abating these hazards are offered, specifically for hazards resulting from the lack of an evacuation plan and absence of an occupant monitoring system.

A Collaborative Design-by-Sketching Conceptual Design Tool for Multimedia Application Development

2011 ◽  
pp. 231-238
Author(s):  
K.-Y. R. Li ◽  
T. Ong ◽  
R. J. Willis
Keyword(s):  
Conceptual Design ◽  
Collaborative Design ◽  
User Involvement ◽  
Cost Effective ◽  
Multimedia Applications ◽  
Design Tool ◽  
Design Stage ◽  
Computer Assisted ◽  
Multimedia Technology ◽  
Application Development

Multimedia technology is advancing at a significant rate and is now revolutionizing the way in which computers are being used in business. Multimedia technology can only benefit a company when applications are properly developed to exploit technology, in order to enhance the company’s operation. Unfortunately, to develop high-quality, cost-effective multimedia applications is not an easy task. There are many issues and challenges that developers are currently facing. Issues such as the difficulties in defining the project scope, communication difficulties amongst the development team, and estimate difficulties, making the development process both labour-intensive and time-consuming (Li and Willis, 1998). Sponsors of multimedia projects are often unsure of their requirements at the start of the project. Sponsor/user involvement in the abstract (conceptual) design stage of the project is therefore important. This chapter presents a computer assisted design-by-sketching tool to help with the conceptual design of multimedia applications. The tool helps sponsors to define their requirement incrementally and the design team to prototype their ideas interactively and collaboratively. It assists the developer to define the balance between consistency, which helps the readers (users) to understand the overall structure, and diversity, which gives freshness to the design. This tool will also enable re-usability of the designed components in future projects and maintainability of the application that it has developed.

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