A Parametric Structure Optimization Method for the Jack-Up Platform

Author(s):  
Yan-yun Yu ◽  
Yan Lin ◽  
Zhuo-shang Ji

In this paper, A parametric structure optimization method, which is called Parametric Structure Shape Optimization Method (PSSOM), is proposed in order to optimize the structure shape of the jack-up platform. According to the characteristic of the jack-up, an approach to create the Parametric Structure Model (PSM) is proposed. The projections of the main structure onto the horizontal plane are used to create the sketch, which is a 2D drawing driven by dimensions. The 3D modeling technique that based on the sketch and feature modeling is used to create the structure model of the jack-up. A meshing procedure is presented to convert PSM into finite element model automatically together with the boundary conditions and the design loads. After calling the FEM solver, the stress and strain for each structure according to any reasonable dimensions could be calculated, and this is the most important foundation of the structure shape optimization design. An optimization design method based on PSM is proposed for the structure optimization design of the jack-up. The genetic algorithm is used to get the optimum dimensions that have better structure strength performance under the premise of that all the other design requirement are satisfied. PSSOM is proved to be practical and high-efficient by the structure optimization of a 300 ft jack-up platform.

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.


Author(s):  
Lei Fu ◽  
Yan Shi ◽  
Qinghua Deng ◽  
Huaizhi Li ◽  
Zhenping Feng

The aerodynamic performance, structural strength and wheel weight are three important factors in the design process of the radial turbine. This paper presents an investigation on these aspects and develops an optimization design approach for radial turbine with consideration of the three factors. The aerodynamic design for the turbine wheel with inlet diameter of 230mm for 100kW-class microturbine unit is carried out firstly as the original design. Then, the cylinder parabolic geometrical design method is applied to the wheel modeling and structural design, but the maximum stress predicted by Finite Element Analysis greatly exceeds the yield limit of material. Furthermore, the wheel weight is above 7.2kg thus bringing some critical difficulties for bearing design and turbine operation. Therefore, an integrated optimization design method for radial turbine is studied and developed in this paper with focus on the wheel design. Meridional profiles and shape lines of turbine wheel are optimized with consideration of the whole wheel weight. Main structural modeling parameters are reselected to reduce the wheel weight. Trade-off between aerodynamic performance and strength performance is highly emphasized during the optimization design. The results show that the optimized turbine wheel gets high aerodynamic performance and acceptable stress distribution with the weight less than 3.8kg.


2014 ◽  
Vol 662 ◽  
pp. 160-163
Author(s):  
Lei Xu

The optimization design method was rarely used to design the gravity buttress of arch dam in the past. With this in mind, the parametric description of gravity buttress is given, and the auto-calculation of its exerting loads and the safety coefficient of anti-slide stability are realized subsequently. Then, the optimization design model of gravity buttress and the procedures of optimization design are presented using the asynchronous particle swarm optimization method. Finally, ODGB software, which is short for Optimization Design of Gravity Buttress software, is developed and verified.


2013 ◽  
Vol 444-445 ◽  
pp. 259-263
Author(s):  
Yan Hong Fan

The effect of steps in the line search on the consistence of adjoint-based drag reduction of airfoil is investigated in this paper. Constant step adopted in drag reduction design usually gives different optimization results and choice of constant step often depends on designers experience and optimization problem. Bracket method is applied to automatically give the optimal step in performing drag reduction design of airfoils RAE2822 and S73613 and the consistent optimal results are obtained. The results illustrate that the linear search method can automatically find the optimal step, and overcome the restriction on choice of user-defined constant step which is used in the traditional adjoint-based optimization method. That is, it reduces the dependence of step in the drag reduction design, and improves the robustness of the adjoint-based airfoil drag reduction optimization design method.


2014 ◽  
Vol 678 ◽  
pp. 325-332
Author(s):  
Feng Yan Yang ◽  
Xiang Zhen Yan ◽  
Zheng Rong Song ◽  
Ming Wang Yang ◽  
Zi Kun Zhao ◽  
...  

The optimization design method of geometric parameters of skid shoe which is used to subject weight of marine structures is proposed. Considering skid shoe as steel frame structure, total weight and the bearing capacity of the skid shoe are selected as optimal objectives, and geometric parameters of the skid shoe are taken as design variables. Taking the strength, stiffness, local stability of the skid shoe as the constraint conditions, multi-objectives constraints optimization model of geometric parameters is established, and solved based on complex method. According to research results, a computer program has been developed using VC language. Then geometric optimum parameters of skid shoe in service of CNOOC are analyzed by the program. The results show that optimized design decreases steel volume, steel plate thickness by 28.7%, 18.4%, respectively, compared with original design. The optimization method has a series of advantages, such as simple model, fast calculating speed, high calculation accuracy.


2020 ◽  
Vol 10 (2) ◽  
pp. 620
Author(s):  
Xinyao Li ◽  
Liangli He

The geotechnical centrifuge applied in various geotechnical engineering fields provides physical data for investigating mechanisms of deformation and failure and for validating analytical and numerical methods by simulating and studying the geotechnical problems. The basket, as one of the important components used to place the inspection model of centrifugal test, is designed to withstand complex loads. This paper presents an optimization design method for the basket based on the weighted B-Spline Finite Cell Method (FCM) and the globally-convergent method of moving asymptotes (GCMMA). In order to obtain a superior design solution, four topological configurations, i.e., original single web, porous dual web, open deep groove dual web, and connected closed dual web, are investigated and optimized. The mass is selected as the optimization objective, while key shape parameters and stress are regarded as design variables and the constraint, respectively. By optimization, the final masses of the four configurations are reduced greatly compared with the initial configurations, where the greatest weight loss, in case 4, is 10.6%. This indicates that the weighted B-Spline FCM and GCMMA can be well applied for shape optimization of structure in engineering design. In contrast to the final single web adopted in the traditional basket design in case 1, the final configuration in case 4, i.e., connected closed dual web, has the least mass. The final mass is reduced by 133.38 kg when the centrifuge strength requirement is met. Therefore, the final configuration in case 4, where the maximum von-Mises stress is 398.72MPa and mass is 781.82 kg, is superior to the three other configurations.


Author(s):  
Hongbin Gao ◽  
Junjun Chen

To improve the robustness of the shearer cutting part and reduce the manufacturing cost, in this study, the gear transmission system of a shearer’s cutting unit can be divided into three basic components: single-gear-on-one-shaft form, the planetary reduction form, and double-gears-on-one-shaft form. The dynamic differential equations of each structure are established in this study, and the volume functions of the three basic components are obtained. The characteristics of the internal excitation of the gear transmission system are analyzed, and a scheme for solving the motion parameters of each component is formulated based on the harmonic balance method. Based on the parameters, such as tooth width, tooth number, and modulus, as optimized variables, a robust optimization method minimizing the multi-parameter evaluation function, which is weighted linearly by dimensionless vibration and volume of the gear transmission system, is presented. The gear transmission system of a sample shearer’s cutting unit is optimized using the proposed method. The results show that the transmission system’s size decreases by 5.4%, the drum’s maximum torsional acceleration decreases by 17.8%, and the first gear’s maximum torsional acceleration decreases by 9.6%. Thus, we conclude that the optimum design method decreases a shearer’s manufacturing cost and decreases the cutting unit’s failure rate.


2011 ◽  
Vol 415-417 ◽  
pp. 460-463
Author(s):  
Li Liu ◽  
Hong Xia Liu

In the design of wrapping hoist, the roller strength is always a larger problem. In this paper, diameter, wall thickness and side plate thickness of the roller were selected as design variables, and volume of the roller acts as object function. Through analyzing its inner stresses, the mechanical model and mathematical model were set up. Adopting the optimization method of covering complex and VB programming software, an application software of a hoist roller optimization design was got. An example is used to verify correctness and practicability of the software. This optimization design method has practical significance on reducing the weight and material of a hoist roller.


Author(s):  
Yu Yang ◽  
Zhigang Wang ◽  
Binwen Wang ◽  
Shuaishuai Lyu

Wing's morphing leading edge, drooping in a seamless way, has significant potential for noise abatement and drag reduction. Innovative design methods for compliant skin and internal actuating mechanism, respectively, are proposed and validated through a mockup in this paper. For the skin, a collaborative optimization method is presented, which takes all design variables, continuous and discrete, into account simultaneously. Moreover, to overcome the drawback of conventional algorithm, which is insufficient for deformation control in critical regime, weight penalty is imposed on present objective function. On the other hand, an internal kinematic actuating mechanism is designed from an improved concept, of which positions of level-rod hinges are optimized in a larger zone to fit the deflection requirement. The test of mockup validates the above methods, and excellent morphing quality of the compliant skin proves the advancement of the collaborative optimization method. However, the design method of internal actuating mechanism needs further improvement, and the error induced deteriorates the final morphing quality of the mockup.


2011 ◽  
Vol 421 ◽  
pp. 212-216 ◽  
Author(s):  
Yong Hou Sun ◽  
Tian Chao Yu ◽  
Ying Sun

Abstract. Car cabin front suspension bracket (CCFSB) plays a supporting role of cab which connected cab cabin and chassis parts. In the conventional design, CCFSB is large and heavy usually to ensure its design strength. Therefore, structure optimization design is becoming the focus on the design of CCFSB. To solve the problem, this paper presents a structure optimization design method of CCFSB based on HyperWorks. The “Analysis-OptiStruct-Refine-Analysis-Contrast” method is proposed to realize the structure optimization. By the process of “meshing-loading- calculating- view of results”, the result of structure optimization of CCFSB is got which shows materials distribution. Trough taking OptiStruct optimization, the weight of CCFSB is reduced about 39% but stiffness is increased. The performance of product is improved and the cost is reduced greatly.


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