Multi-Objective Optimization Design of Flexible Risers Based on Bi-Scale Response Surface Models

2018 ◽  
Author(s):  
Zhixun Yang ◽  
Jun Yan ◽  
Svein Sævik ◽  
Luqing Zhen ◽  
Naiquan Ye ◽  
...  
Keyword(s):  
Response Surface ◽  
Response Surface Model ◽  
Surface Model ◽  
Flexible Riser ◽  
Optimization Framework ◽  
Scale Response ◽  
Design Variables ◽  
Global Configuration ◽  
Flexible Risers ◽  
Scale Optimization

An optimized flexible riser design not only requests that the stress of local cross-section shouldn’t exceed the allowable strength, but also can be compliant with the floater to improve the fatigue life. It should be particularly pointed out that the flexible riser is a typical multi-scale system, which consists of the local cross-sectional scale and the global configuration scale, which differentiates each other a lot from their geometrical scales. A bi-scale response surface model is established to perform the optimized design of flexible risers by considering the parameters of local cross-sections and global configurations simultaneously. The response surface model can be an effective surrogate model to integrate the local and global responses into one loop so that the computational efficiency can be increased significantly. In the bi-scale response model, design variables of a flexible riser are extracted and defined at both the local sectional scale and global configuration scale. Sensitivity analyses of the two objectives, ultimate tension and bending strength on the design variables are then deduced to establish the bi-scale optimization framework through the response surface methodology. Finally, the optimization framework is implemented on a flexible riser with lazy-wave configuration which is considered as a case study. The properties of the optimized flexible risers are compared with those without the optimization. It is found that the ultimate load bearing capacity and fatigue life of the optimized flexible riser are improved significantly. Moreover, the feasibility and effectiveness of the bi-scale optimization strategy are verified through numerical simulations, which indicates that the bi-scale response surface optimization methodology provides a new thought and approach to explore the design potential of flexible risers.

Optimization Design of Pressure Shell in Underwater Vehicle Based on Response Surface Model

2009 ◽  
Vol 419-420 ◽  
pp. 89-92
Author(s):  
Zhuo Yi Yang ◽  
Yong Jie Pang ◽  
Zai Bai Qin
Keyword(s):  
Finite Element ◽  
Response Surface ◽  
Optimization Design ◽  
Engineering Application ◽  
Element Model ◽  
Response Surface Model ◽  
Design Stage ◽  
Surface Model ◽  
Design Variables ◽  
Structure Strength

Cylinder shell stiffened by rings is used commonly in submersibles, and structure strength should be verified in the initial design stage considering the thickness of the shell, the number of rings, the shape of ring section and so on. Based on the statistical techniques, a strategy for optimization design of pressure hull is proposed in this paper. Its central idea is that: firstly the design variables are chosen by referring criterion for structure strength, then the samples for analysis are created in the design space; secondly finite element models corresponding to the samples are built and analyzed; thirdly the approximations of these analysis are constructed using these samples and responses obtained by finite element model; finally optimization design result is obtained using response surface model. The result shows that this method that can improve the efficiency and achieve optimal intention has valuable reference information for engineering application.

Optimization of Double Pivot Suspension Kingpin Axis during Steering

2014 ◽  
Vol 551 ◽  
pp. 232-236
Author(s):  
Tian Ze Shi ◽  
Deng Feng Wang ◽  
Shu Ming Chen ◽  
Hong Liang Dong
Keyword(s):  
Response Surface ◽  
Response Surface Model ◽  
Prototype Model ◽  
Surface Model ◽  
Suspension Parameters ◽  
Design Variables ◽  
Kingpin Axis ◽  
Relationship Of ◽  
The Relationship ◽  
Suspension Performance

A double pivot suspension used for in-wheel motor electric vehicle was designed, and the virtual prototype model of the suspension assembly was build. The suspension parameters changed greatly during steering. In order to solve this problem, this paper proposed a non-linear response surface model to fit the relationship of suspension parameters and design variables. An optimization scheme was designed based on the response surface model. The suspension performance was improved significantly using optimized variables.

Response Surface Algorithms for Engine Mount Optimization in Motorcycles

2009 ◽  
Author(s):  
Sudhir Kaul ◽  
Anoop K. Dhingra
Keyword(s):  
Response Surface ◽  
Optimization Problem ◽  
Vibration Isolation ◽  
Design Space ◽  
Substantial Reduction ◽  
Response Surface Model ◽  
Fractional Factorial ◽  
Surface Model ◽  
Design Variables ◽  
Engine Mount

This paper presents a Response Surface Modeling (RSM) approach for solving the engine mount optimization problem for a motorcycle application. A theoretical model that captures the structural dynamics of a motorcycle engine mount system is first used to build the response surface model. The response surface model is then used to solve the engine mount optimization problem for enhanced vibration isolation. Design of Experiments (DOE), full factorial and fractional factorial formulations, are used to construct the governing experiments. Normal probability plots are used to determine the statistical significance of the variables and the significant variables are then used to build the response surface. The design variables for the engine mount optimization problem include mount stiffness, position vectors and orientation vectors. It is seen that RSM leads to a substantial reduction in computational effort and yields a simplified input-output relationship between the variables of interest. However, as the number of design variables increases and as the response becomes irregular, conventional use of RSM is not viable. Two algorithms are proposed in this paper to overcome the issues associated with the size of the governing experiments and problems associated with modeling of the orientation variables. The proposed algorithms divide the design space into sub-regions in order to manage the size of the governing experiments without significant confounding of variables. An iterative procedure is used to overcome high response irregularity in the design space, particularly due to orientation variables.

scholarly journals Parametric Analysis on Landing Gear Strut Friction of Light Aircraft for Touchdown Performance

2021 ◽  
Vol 11 (12) ◽  
pp. 5445
Author(s):  
Shengyong Gan ◽  
Xingbo Fang ◽  
Xiaohui Wei
Keyword(s):  
Response Surface ◽  
Energy Absorption ◽  
Landing Gear ◽  
Surface Model ◽  
Absorption Properties ◽  
Surface Method ◽  
Design Variables ◽  
Landing Impact ◽  
Landing Response ◽  
Parametric Studies

The aim of this paper is to obtain the strut friction–touchdown performance relation for designing the parameters involving the strut friction of the landing gear in a light aircraft. The numerical model of the landing gear is validated by drop test of single half-axle landing gear, which is used to obtain the energy absorption properties of strut friction in the landing process. Parametric studies are conducted using the response surface method. Based on the design of the experiment results and response surface functions, the sensitivity analysis of the design variables is implemented. Furthermore, a multi-objective optimization is carried out for good touchdown performance. The results show that the proportion of energy absorption of friction load accounts for more than 35% of the total landing impact energy. The response surface model characterizes well for the landing response, with a minimum fitting accuracy of 99.52%. The most sensitive variables for the four landing responses are the lower bearing width and the wheel moment of inertia. Moreover, the max overloading of sprung mass in LC-1 decreases by 4.84% after design optimization, which illustrates that the method of analysis and optimization on the strut friction of landing gear is efficient for improving the aircraft touchdown performance.

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