Spatial Incompatibility: Part Interaction and Tolerance Allocation in Configuration Design

1998 ◽  
Author(s):  
Rikard Söderberg ◽  
Hans L. Johannesson
Keyword(s):  
Cost Effective ◽  
Tolerance Allocation ◽  
Design Parameters ◽  
Functional Requirements ◽  
Early Design ◽  
Spatial Coupling ◽  
Assembly Design ◽  
Geometrical Features ◽  
Cad Models ◽  
Early Design Stages

Abstract This paper describes how function-means modeling techniques and spatial coupling analysis can be used in early design stages to increase robustness and knowledge about geometrical sensitivity of an assembly design. By incorporating spatial constraint decomposition in function-means modeling, overall spatial constraints may be broken down into nominal dimensions and tolerances for geometrical features. The analysis is carried out at the very early design stages, before CAD models are created and when only simple sketches exist. By documenting all information about functional requirements, design parameters and constraints in a hierarchically decomposed function-means structure, spatial couplings and overall sensitivities may be detected and alternative, less sensitive, concept solutions may be developed. Analyses of functional and constraint couplings increases the knowledge of and understanding for the geometrical sensitivity of a complex assembly design. This knowledge and understanding then serves as a base for tolerance allocation, where tolerances are to be allocated in the most functional and cost effective way.

Influence of Design Parameters on Vertical Motions of Trawler Hull Forms in Head Seas

1997 ◽  
Vol 34 (03) ◽  
pp. 181-196
Author(s):  
Abdi Kukner ◽  
Muhsin Aydm
Keyword(s):  
Computer Program ◽  
Froude Number ◽  
Regression Models ◽  
Ship Motion ◽  
Design Parameters ◽  
Radius Of Gyration ◽  
Early Design ◽  
Early Design Stages ◽  
Hull Forms

The influence of ship length, length to beam ratio, beam to draft ratio, prismatic coefficient, non-dimensional radius of gyration and Froude number upon significant amplitude of coupled heaving and pitching motions of trawler hull forms for six different sea states has been studied. For this purpose, 540 trawler hull forms have been generated from Doust trawler series to cover appropriate ranges of the design parameters. Seakeeping behavior of these forms has been studied by using an established ship motion computer program and regression models of significant seakeeping events have been derived. Through this study, it is believed that a method has been produced for the seakeeping evaluation of trawler forms during the early design stages, hence allowing for the design of safer and more seakindly trawler designs.

Electrochemical cleaning of soils with different concentrations of oil pollution using a single source of electrical voltage

2020 ◽  
Vol 10 (6) ◽  
pp. 674-680
Author(s):  
Nikolay S. Shulaev ◽  
◽  
Valeriya V. Pryanichnikova ◽  
Ramil R. Kadyrov ◽  
Inna V. Ovsyannikova ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Oil Pollution ◽  
Cost Effective ◽  
Electrical Energy ◽  
Design Parameters ◽  
Technological Infrastructure ◽  
Chemical Reagents ◽  
Electrode Space ◽  
Soil Excavation ◽  
Interelectrode Resistance

The most essential scientifific and practical task in the area of ecological safety of pipelines operation is the development and improvement of methods of purifification and restoration of oil-contaminated soils. One of the most effificient and cost effective methods is electrochemical purifification, that does not require the use of expensive chemical reagents and soil excavation. However, the consideration of non-uniform contamination of various soil sections is required. The article examines the features of the organization and technological infrastructure for electrochemical purifification of non-uniformly contaminated soils when using a single electrical energy source, a method for calculating the design parameters of the corresponding installation is proposed. Effificient purifification of non-uniformly contaminated soil when using a specifified voltage is possible through the use of different-sized electrodes. For each soil type, the amount of transmitted electric charge required for soil purifification is determined by the concentration of the contaminant. Allocation of cathodes and anodes as parallel batteries and their connection using individual buses is an effective and energy-effificient solution, since an almost-uniform electric fifield is created in an inter-electrode space, thus allowing the reduction of the interelectrode resistance of the medium.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

Systems Thinking in Aerospace: The Contributions to the Design of Future Airliners’ Single Pilot Operations

2020 ◽  
Vol 64 (1) ◽  
pp. 188-192
Author(s):  
Daniela Schmid ◽  
Neville A. Stanton
Keyword(s):  
Literature Review ◽  
Human Factors ◽  
Systems Thinking ◽  
Systematic Literature Review ◽  
Hierarchical Structures ◽  
Theoretical Models ◽  
Sociotechnical Systems ◽  
System Behavior ◽  
Early Design ◽  
Early Design Stages

Systems thinking methods have evolved into a popular toolkit in Human Factors to analyze complex sociotechnical systems at early design stages, such as future airliners’ single pilot operations (SPO). A quantitative re-analysis of studies from a systematic literature review (Schmid & Stanton, 2019b) was conducted to categorically assess their contributions to researching SPO and to fitting their systems thinking methods to contemporary Human Factors problems. Although only 15 of 79 publications applied systems thinking methods to operational, automation, and the pilot incapacitation issue(s) of SPO, these studies provided a comprehensive concept of operations that is able to deal with many issues of future single-piloted airliners. These theoretical models require further evaluation by looking at the empirical instances of system behavior. Finally, the hierarchical structures in system’s development and operations from systems thinking enable Human Factors professionals and researchers to approach SPO systematically.

Analytic Optimization of Cost Effective Thermoelectric Generation on Top of Rankine Cycle

2013 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Yee Rui Koh ◽  
Ali Shakouri
Keyword(s):  
Steam Turbine ◽  
Fuel Efficiency ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Energy Conversion Efficiency ◽  
Design Parameters ◽  
Steam Temperature ◽  
Combined System ◽  
Fuel Consumption Rate ◽  
The Impact

Thermoelectric (TE) generators have a potential advantage of the wide applicable temperature range by a proper selection of materials. In contrast, a steam turbine (ST) as a Rankine cycle thermodynamic generator is limited up to more or less 630 °C for the heat source. Unlike typical waste energy recovery systems, we propose a combined system placing a TE generator on top of a ST Rankine cycle generator. This system produces an additional power from the same energy source comparing to a stand-alone steam turbine system. Fuel efficiency is essential both for the economic efficiency and the ecological friendliness, especially for the global warming concern on the carbon dioxide (CO2) emission. We report our study of the overall performance of the combined system with primarily focusing on the design parameters of thermoelectric generators. The steam temperature connecting two individual generators gives a trade-off in the system design. Too much lower the temperature reduces the ST performance and too much higher the temperature reduces the temperature difference across the TE generator hence reduces the TE performance. Based on the analytic modeling, the optimum steam temperature to be designed is found near at the maximum power design of TE generator. This optimum point changes depending on the hours-of-operation. It is because the energy conversion efficiency directly connects to the fuel consumption rate. As the result, physical upper-limit temperature of steam for ST appeared to provide the best fuel economy. We also investigated the impact of improving the figure-of-merit (ZT) of TE materials. As like generic TE engines, reduction of thermal conductivity is the most influential parameter for improvement. We also discuss the cost-performance. The combined system provides the payback per power output at the initial and also provides the significantly better energy economy [$/KWh].

Design optimization approach comparing multicriterial variants using BIM in early design stages

2021 ◽  
Author(s):  
Kasimir Forth ◽  
Jimmy Abualdenien ◽  
André Borrmann ◽  
Sabrina Fellermann ◽  
Christian Schunicht
Keyword(s):  
Design Optimization ◽  
Optimization Approach ◽  
Early Design ◽  
Early Design Stages

Parametric real-time energy analysis in early design stages: a method for residential buildings in Germany

2017 ◽  
Vol 3 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Alexander Hollberg ◽  
Thomas Lichtenheld ◽  
Norman Klüber ◽  
Jürgen Ruth
Keyword(s):  
Real Time ◽  
Energy Analysis ◽  
Residential Buildings ◽  
Early Design ◽  
Early Design Stages

Identification of Human Errors During Early Design Stage Functional Failure Analysis

2018 ◽  
Author(s):  
Lukman Irshad ◽  
Salman Ahmed ◽  
Onan Demirel ◽  
Irem Y. Tumer
Keyword(s):  
Failure Analysis ◽  
Human Error ◽  
System Level ◽  
Design Stage ◽  
Human Factors Engineering ◽  
Human Errors ◽  
Functional Failure ◽  
Early Design ◽  
Early Design Stage ◽  
Early Design Stages

Detection of potential failures and human error and their propagation over time at an early design stage will help prevent system failures and adverse accidents. Hence, there is a need for a failure analysis technique that will assess potential functional/component failures, human errors, and how they propagate to affect the system overall. Prior work has introduced FFIP (Functional Failure Identification and Propagation), which considers both human error and mechanical failures and their propagation at a system level at early design stages. However, it fails to consider the specific human actions (expected or unexpected) that contributed towards the human error. In this paper, we propose a method to expand FFIP to include human action/error propagation during failure analysis so a designer can address the human errors using human factors engineering principals at early design stages. To explore the capabilities of the proposed method, it is applied to a hold-up tank example and the results are coupled with Digital Human Modeling to demonstrate how designers can use these tools to make better design decisions before any design commitments are made.

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