A Design Approach for Storage Spar Buoy Platforms in the Concept and Preliminary Design Phases

Author(s):  
Richard David Schachter ◽  
Carlos Gomes Jordani ◽  
Antonio Carlos Fernandes

The objective of this work is to present a design approach for the Concept and Preliminary Design Phases of Storage SPAR Buoy Platforms and to describe how the design method was developed. The influence of a VIV porosity device on the design is taken into consideration. The inherent advantages of Spar concepts for Petrobras’ applications for 1250 m, are discussed and compared with other concepts. The Spar concept was chosen. The design method development was carried out by means of a brainstorming process, using sketches and the creation of interactive flowcharts of the design processes (similar to a design spiral) comprising the main design factors, their sequencing and interrelations, for both the Concept and Preliminary Design phases. The intent of the design approach is to provide the designer with means to define quick and efficiently the optimal hull dimensions for a pre-established scenario. For the Concept Design, the method includes the definition of the main dimensions, the Wellbay, the structural topology and compartmentation, general arrangement, weight control, stability (intact, damaged and flooded), motions and mooring. A discussion on the influence of the VIV porosity device on the dimensioning and mooring of the Spar Platform is provided. A concept design application example is presented.

Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.


2012 ◽  
Vol 215-216 ◽  
pp. 804-807
Author(s):  
Xiang Dong He ◽  
Jia Peng Chu

In engineering design, according to not considering past experience information; hence, to make structure parameters for achieving high confidence level, much data for traditional reliability-based robust design must be adequately collected, analyzed, and tested. However, in practical engineering, it is very difficult for doing much test, only for getting in the form of finite test samples. Under the conditions, it has much difficult for the traditional reliability-based robust design. In the article, we present a new reliability-based robust design method that solves the form of incomplete information. The method adopts a Bayesian inference technique to estimate reliability, gives definition of Bayesian reliability. In the research, the mechanical parts bayesian reliability-based robust design mathematical model is established and the bayesian reliability-based robust design approach is presented. The numerical results illustrates the method presented is an efficient and practical reliability-based robust design approach.


Author(s):  
Giuseppe Di Gironimo ◽  
Mariano Guida ◽  
Antonio Lanzotti ◽  
Amalia Vanacore

In this work we apply an innovative participative design approach for the quality evaluation of virtual prototypes of new industrial products (i.e. concept designs), by adopting statistical procedures and carrying out tests in an immersive VR environment. This methodology has been fully exploited through a case study concerning the choice of the optimal design for the interiors of a new regional train. Following this approach, the optimal concept design is defined at the end of a process consisting of five phases: identification of the quality elements of the concept design, classification of the quality elements, generation and quality evaluation of product concepts and, finally, definition of the optimal concept. According to the applied methodology after the identification of the customer’s needs, a structured set of quality elements has been defined and, successively, classified according to Kano’s theory. Following the approach of conjoint analysis, the design factors have been combined according to an experimental plan to form product virtual concepts. During the concepts generation phase we have explored those product architectures that integrate design characteristics correlated to the set of quality elements. The concepts have been created according to comfort, ergonomic and safety criteria. In particular we have considered the ergonomics of places and furniture dimensions, through the use of virtual manikins. The evaluation of the quality of the different concepts has been carried out in the VR laboratory (named “VRTest”) of the Competence Centre for the Qualification of Transportation Systems founded by Regione Campania according to an original statistical procedure and has involved a group of experts in train’s interiors design and a group of common users of regional trains.


2017 ◽  
Vol Vol 159 (A3) ◽  
Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.


2014 ◽  
Vol 2014.24 (0) ◽  
pp. _2214-1_-_2214-10_
Author(s):  
Yuji KADO ◽  
Yusuke MARU ◽  
Hiroshi MIYOSHI ◽  
Shoji TAKECHI ◽  
Kunihiro HAMADA ◽  
...  

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji

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.


Author(s):  
Mathias Stefan Roeser ◽  
Nicolas Fezans

AbstractA flight test campaign for system identification is a costly and time-consuming task. Models derived from wind tunnel experiments and CFD calculations must be validated and/or updated with flight data to match the real aircraft stability and control characteristics. Classical maneuvers for system identification are mostly one-surface-at-a-time inputs and need to be performed several times at each flight condition. Various methods for defining very rich multi-axis maneuvers, for instance based on multisine/sum of sines signals, already exist. A new design method based on the wavelet transform allowing the definition of multi-axis inputs in the time-frequency domain has been developed. The compact representation chosen allows the user to define fairly complex maneuvers with very few parameters. This method is demonstrated using simulated flight test data from a high-quality Airbus A320 dynamic model. System identification is then performed with this data, and the results show that aerodynamic parameters can still be accurately estimated from these fairly simple multi-axis maneuvers.


2021 ◽  
Vol 1 ◽  
pp. 2691-2700
Author(s):  
Stefan Goetz ◽  
Dennis Horber ◽  
Benjamin Schleich ◽  
Sandro Wartzack

AbstractThe success of complex product development projects strongly depends on the clear definition of target factors that allow a reliable statement about the fulfilment of the product requirements. In the context of tolerancing and robust design, Key Characteristics (KCs) have been established for this purpose and form the basis for all downstream activities. In order to integrate the activities related to the KC definition into product development as early as possible, the often vaguely formulated requirements must be translated into quantifiable KCs. However, this is primarily a manual process, so the results strongly depend on the experience of the design engineer.In order to overcome this problem, a novel computer-aided approach is presented, which automatically derives associated functions and KCs already during the definition of product requirements. The approach uses natural language processing and formalized design knowledge to extract and provide implicit information from the requirements. This leads to a clear definition of the requirements and KCs and thus creates a founded basis for robustness evaluation at the beginning of the concept design stage. The approach is exemplarily applied to a window lifter.


Author(s):  
Jan Schumann ◽  
Ulrich Harbecke ◽  
Daniel Sahnen ◽  
Thomas Polklas ◽  
Peter Jeschke ◽  
...  

The subject of the presented paper is the validation of a design method for HP and IP steam turbine stages. Common design processes have been operating with simplified design methods in order to quickly obtain feasible stage designs. Therefore, inaccuracies due to assumptions in the underlying methods have to be accepted. The focus of this work is to quantify the inaccuracy of a simplified design method compared to 3D Computational Fluid Dynamics (CFD) simulations. Short computing time is very convenient in preliminary design; therefore, common design methods work with a large degree of simplification. The origin of the presented analysis is a mean line design process, dealing with repeating stage conditions. Two features of the preliminary design are the stage efficiency, based on loss correlations, and the mechanical strength, obtained by using the beam theory. Due to these simplifications, only a few input parameters are necessary to define the primal stage geometry and hence, the optimal design can easily be found. In addition, by using an implemented law to take the radial equilibrium into account, the appropriate twist of the blading can be defined. However, in comparison to the real radial distribution of flow angles, this method implies inaccuracies, especially in regions of secondary flow. In these regions, twisted blades, developed by using the simplified radial equilibrium, will be exposed to a three-dimensional flow, which is not considered in the design process. The analyzed design cases show that discrepancies at the hub and shroud section do exist, but have minor effects. Even the shroud section, with its thinner leading-edge, is not vulnerable to these unanticipated flow angles.


Author(s):  
Mads Baandrup ◽  
Ole Sigmund ◽  
Niels Aage

<p>This work applies a ultra large scale topology optimization method to study the optimal structure of bridge girders in cable supported bridges.</p><p>The current classic orthotropic box girder designs are limited in further development and optimiza­ tion, and suffer from substantial fatigue issues. A great disadvantage of the orthotropic girder is the loads being carried one direction at a time, thus creating stress hot spots and fatigue problems. Hence, a new design concept has the potential to solve many of the limitations in the current state­ of-the-art.</p><p>We present a design method based on ultra large scale topology optimization. The highly detailed structures and fine mesh-discretization permitted by ultra large scale topology optimization reveal new design features and previously unseen eff ects. The results demonstrate the potential of gener­ ating completely different design solutions for bridge girders in cable supported bridges, which dif­ fer significantly from the classic orthotropic box girders.</p><p>The overall goal of the presented work is to identify new and innovative, but at the same time con­ structible and economically reasonable, solutions tobe implemented into the design of future cable supported bridges.</p>


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