Optimal Design of Semisubmersible’s Form Based on Systems Analysis

1984 ◽  
Vol 106 (4) ◽  
pp. 524-530 ◽  
Author(s):  
S. Akagi ◽  
R. Yokoyama ◽  
K. Ito

With the objective of developing a computer-aided design method to seek the optimal semisubmersible’s form, hierarchical relationships among many design objectives and conditions are investigated first based on the interpretive structural modeling method. Then, an optimal design method is formulated as a nonlinear multiobjective optimization problem by adopting three mutually conflicting design objectives. A set of Pareto optimal solutions is derived numerically by adopting the generalized reduced gradient algorithm, and it is ascertained that the designer can determine the optimal form more rationally by investigating the trade-off relationships among design objectives.

1984 ◽  
Vol 106 (4) ◽  
pp. 503-509
Author(s):  
Koichi Ito ◽  
Tadashi Kuroiwa ◽  
Shinsuke Akagi

A nonlinear optimization method is proposed to design a linkage mechanism used for opening and shutting a ship’s hatch cover. Considering the maximum force of the oil cylinder necessary to move the hatch cover as the objective function to be minimized, the design problem to determine the optimal configuration of linkage mechanism is formulated as a nonlinear optimization problem of minimax type. It it shown that the optimal solution can be derived by adopting the generalized reduced gradient algorithm together with a linkage statical simulation model, and the effectiveness of the algorithm is ascertained through a numerical study.


Author(s):  
Toru Matsushima ◽  
Shinji Nishiwaki ◽  
Shintarou Yamasaki ◽  
Kazuhiro Izui ◽  
Masataka Yoshimura

Minimizing brake squeal is one of the most important issues in the development of high performance braking systems. Recent advances in numerical analysis, such as finite element analysis, have enabled sophisticated analysis of brake squeal phenomena, but current design methods based on such numerical analyses still fall short in terms of providing concrete performance measures for minimizing brake squeal in high performance design drafts at the conceptual design phase. This paper proposes an optimal design method for disc brake systems that specifically aims to reduce brake squeal by appropriately modifying the shapes of the brake system components. First, the relationships between the occurrence of brake squeal and the geometry and characteristics of various components is clarified, using a simplified analysis model. Next, a new design performance measure is proposed for evaluating brake squeal performance and an optimization problem is then formulated using this performance measure as an objective function. The optimization problem is solved using Genetic Algorithms. Finally, a design example is presented to examine the features of the optimal solutions and confirm that the proposed method can yield useful design information for the development of high performance braking systems that minimize brake squeal.


2011 ◽  
Vol 187 ◽  
pp. 528-534 ◽  
Author(s):  
Hua Bin Wen ◽  
Yong Duan Song ◽  
Rui Li

The optimal design of vacuum switch is becoming an important research topic with the extensive application and increasing demands of vacuum switches. This paper analyzes the main elements of the vacuum switch design, and gives the design process of the vacuum switch. An optimal design method is proposed for the vacuum switch based on the concept and characteristics of virtual prototyping (VP) technology. By using computer aided design and the related software, we propose a method for vacuum switch modeling VP, the stress field VP of parts, the thermal field VP of electric heat, the electric field VP of insulation parts and the mechanical dynamic VP of kinematics system, which are integrated for optimization design for vacuum switches. This work is expected to provide a new idea for optimal and rapid design of vacuum switches.


2021 ◽  
Vol 11 (7) ◽  
pp. 3266
Author(s):  
Insub Choi ◽  
Dongwon Kim ◽  
Junhee Kim

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.


2021 ◽  
Vol 249 ◽  
pp. 113262
Author(s):  
FeiFei Sun ◽  
Guang Yang ◽  
ZhiBin Hu

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