Effects of Design Parameter on Occurrence of Snap Load and Wear of Mooring Line for Spar-Buoy With Ring-Fin Motion Stabilizer for Shallow Sea

2021 ◽  
Author(s):  
Yusuke Yamamoto ◽  
Taishi Morimoto ◽  
Toru Katayama ◽  
Masahiro Goto ◽  
Ryo Kodama
Keyword(s):  
Design Method ◽  
Empirical Method ◽  
Horizontal Motion ◽  
Design Parameters ◽  
Mooring Line ◽  
Wave Excitation ◽  
Shallow Sea ◽  
Optimal Design Method ◽  
Motion Mode ◽  
Acceleration Component

Abstract The purpose of this study is to propose an optimal design method of the spar-buoy with ring-fin motion stabilizer for shallow sea and its mooring system, in order to avoid the occurrence of snap load. The mechanism of occurrence of snap load is investigated by model tests, and design parameters for avoiding the occurrence of snap load are investigated. From the observation of model’s motion, it has been realized that the snap load is caused by the tension of mooring line to stop the buoy’s horizontal motion, which relaxes the mooring line. Moreover, it has been confirmed that the horizontal motion is caused by the horizontal forces acting on the center pipe and float of the buoy, which relates to the acceleration component of wave excitation forces. In this paper, the effects of changing of design of the buoy (: diameter of center pipe and float, size of stabilizer, density of the buoy, length of mooring line) on avoiding or reducing snap load are investigated by using a numerical simulation (OrcaFlexver.11.0b), and the wear amounts are also estimated by using an empirical method (Takeuchi et al., 2019). From the results, it is confirmed that changing the buoy’s motion mode by shortening mooring line is effective to avoiding the occurrence of snap load, and to reduce the wear amount of the mooring line.

Research on the Optimal Design Method of the Main Components for the Wheelchair Pickup

2013 ◽  
Vol 791-793 ◽  
pp. 799-802
Author(s):  
Ya Ping Wang ◽  
H.R. Shi ◽  
L. Gao ◽  
Z. Wang ◽  
X.Y. Jia ◽  
...  
Keyword(s):  
Parametric Design ◽  
Design Method ◽  
Basic Function ◽  
Design Parameters ◽  
Algorithm Optimization ◽  
Optimization Analysis ◽  
Research Designs ◽  
Optimal Design Method ◽  
Main Components

With the increasing of the aging of population all over the world, and With the inconvenience coming from diseases and damage, there will be more and more people using the wheelchair as a tool for transport. When it cant be short of the wheelchair in the daily life, the addition of the function will bring the elevation of the quality of life for the unfortunate. Staring with this purpose, the research designs a pickup with planetary bevel gear for the wheelchair. After determining the basic function of the wheelchair aids, the study determines the design parameters by using the knowledge of parametric design and completes the model for the system with Pro/E, on the other hand, it completes key components optimization analysis which is based on genetic algorithm optimization.

scholarly journals An Optimal Design Method for Compliant Mechanisms

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Ngoc Le Chau ◽  
Ngoc Thoai Tran ◽  
Thanh-Phong Dao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Optimal Design ◽  
Compliant Mechanisms ◽  
Design Method ◽  
Fitness Function ◽  
Current Method ◽  
Design Parameters ◽  
Optimal Design Method ◽  
Element Method

Compliant mechanisms are crucial parts in precise engineering but modeling techniques are restricted by a high complexity of their mechanical behaviors. Therefore, this paper devotes an optimal design method for compliant mechanisms. The integration method is a hybridization of statistics, finite element method, artificial intelligence, and metaheuristics. In order to demonstrate the superiority of the method, one degree of freedom is considered as a study object. Firstly, numerical datasets are achieved by the finite element method. Subsequently, the main design parameters of the mechanism are identified via analysis of variance. Desirability of both displacement and frequency of the mechanism is determined, and then, they are embedded inside a fuzzy logic system to combine into a single fitness function. Then, the relationship between the fine design variables and the fitness function is modeled using the adaptive network-based fuzzy inference system. Next, the single fitness function is maximized via moth-flame optimization algorithm. The optimal results determined that the frequency is 79.517 Hz and displacement is 1.897 mm. In terms of determining the global optimum solution, the current method is compared with the Taguchi, desirability, and Taguchi-integrated fuzzy methods. The results showed that the current method is better than those methods. Additionally, the devoted method outperforms the other metaheuristic algorithms such as TLBO, Jaya, PSOGSA, SCA, ALO, and LAPO in terms of faster convergence. The result of this study will be considered to apply for multiple-degrees-of-freedom compliant mechanisms in future work.

Early-Stage Analysis for MEMS Structural Optimization I: Concept

2005 ◽  
Author(s):  
Takahiro Miki ◽  
Koji Ishikawa ◽  
Hiroki Mamiya ◽  
Qiang Yu
Keyword(s):  
Optimal Design ◽  
Early Stage ◽  
Design Method ◽  
Design Stage ◽  
Design Parameters ◽  
Total System ◽  
Trade Offs ◽  
Optimal Design Method ◽  
Stage Analysis ◽  
System Characteristics

We report on the development of a new micro-electro-mechanical systems (MEMS) optimal design method called MEMS Early-Stage Analysis (MESA), which supports the total system evaluation of MEMS devices before the design stage. Recently total system simulation and design using Computer Aided Engineering (CAE) analyses have become important in MEMS device development due to their fabrication and design complexity. Although a lot of CAE methods that can be applied to MEMS have been demonstrated, time-consuming trial-and-error processes are inevitable at the design stage in order to obtain an optimal structure. In our design method, we can clarify and simplify the relation between design parameters and the system characteristics using a MESA weighted orthogonal array. In the MESA array, the sensitivity of each design factor for the system performance shows numerically how the design parameter influences the system characteristics. The existent trade-offs between design parameters can be minimized by both modifying the design concept and adjusting the sensitivities. Therefore MEMS designers are able to optimize the total system based on the information from the MESA array. Moreover, particular system characteristics can be enhanced in order to meet the system requirement through the adjustment of weight values for the sensitivities. The MESA makes the evaluation of system validity possible at the concept design stage. To conduct the informative optimal design method at the beginning of development leads the reduction of the total MEMS design time and cost.

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.

scholarly journals Development of Optimal Design Method for Steel Double-Beam Floor System Considering Rotational Constraints

2021 ◽  
Vol 11 (7) ◽  
pp. 3266
Author(s):  
Insub Choi ◽  
Dongwon Kim ◽  
Junhee Kim
Keyword(s):  
Optimal Design ◽  
Design Process ◽  
Design Method ◽  
Steel Beams ◽  
High Gravity ◽  
Double Beam ◽  
Iterative Analysis ◽  
Floor Systems ◽  
Optimal Design Method ◽  
Floor System

Under high gravity loads, steel double-beam floor systems need to be reinforced by beam-end concrete panels to reduce the material quantity since rotational constraints from the concrete panel can decrease the moment demand by inducing a negative moment at the ends of the beams. However, the optimal design process for the material quantity of steel beams requires a time-consuming iterative analysis for the entire floor system while especially keeping in consideration the rotational constraints in composite connections between the concrete panel and steel beams. This study aimed to develop an optimal design method with the LM (Length-Moment) index for the steel double-beam floor system to minimize material quantity without the iterative design process. The LM index is an indicator that can select a minimum cross-section of the steel beams in consideration of the flexural strength by lateral-torsional buckling. To verify the proposed design method, the material quantities between the proposed and code-based design methods were compared at various gravity loads. The proposed design method successfully optimized the material quantity of the steel double-beam floor systems without the iterative analysis by simply choosing the LM index of the steel beams that can minimize objective function while satisfying the safety-related constraint conditions. In particular, under the high gravity loads, the proposed design method was superb at providing a quantity-optimized design option. Thus, the proposed optimal design method can be an alternative for designing the steel double-beam floor system.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

CFD analysis and RSM optimization of obstacle layout in Tesla micromixer

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaowen Wang ◽  
Lihong Yang ◽  
Fujia Sun
Keyword(s):  
Chemical Reaction ◽  
Chemical Engineering ◽  
Design Method ◽  
Mixing Rate ◽  
Special Flow ◽  
Surface Method ◽  
Rsm Optimization ◽  
Effective Technology ◽  
Optimal Design Method ◽  
Lateral Offset

Abstract As a kind of fast and efficient mixing equipment, micromixer has been applied to chemical reaction detection. Its application can not only save experimental samples but also reduce the experimental time. In micromixers, Tesla structure is widely used due to its simple structure and special flow mechanism. In this paper, CFD and response surface method are used to analyze and verify the flow field of the configuration of adding diamond obstacles in the Tesla mixer. The results show that the order of layout parameter weight from large to small is obstacle size > vertical offset > horizontal offset. And the Desirability was 0.806, the optimal diamond obstacle size is 46.35 μm and the optimal lateral offset is 18.78 μm. In addition, a constant value OF 20 μm is predicted as the optimal vertical offset of the micromixer. Compared with the Tesla-type micromixer without obstacles, the diamond-shaped barrier Tesla-type micromixer designed in this paper has higher mixing rate and lower pressure drop under the same conditions, which can be applied to chemical reactors, and can also help to improve the accuracy of chemical reaction. It can be demonstrated that the presented optimal design method of obstacles layout in Tesla mixer is a simple and effective technology to improve the liquid mixing in microfluidic devices, and it has a broad application prospect in chemical engineering.

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