Optimal Design and Analysis of UAV Swan Fuselage

2006 ◽  
Vol 113 ◽  
pp. 91-96 ◽  
Author(s):  
Priit Leomar ◽  
Mart Tamre ◽  
Tõnis Riibe ◽  
Tõnu Vaher ◽  
Toomas Haggi
Keyword(s):  
Finite Element ◽  
Material Design ◽  
Unmanned Aircraft ◽  
Design Stage ◽  
Early Design Stage ◽  
Design Variables ◽  
University Of Technology ◽  
Production Period ◽  
Method Analysis ◽  
Advanced Computer

Eli Ltd. and Tallinn University of Technology (TUT) Department of Mechatronics are currently performing studies in order to develop a mini-class universal purpose unmanned aircraft [1,2]. The paper focuses on strength calculations and weight vs. strength optimization of the fuselage of this developed UAV system. To develop a strong but lightweight UAV fuselage, advanced computer modeling and finite element structure analysis are used as virtual prototyping tools for the optimization of the fuselage at early design stage and through the production period to improve the design [3]. Design optimization is applied to minimize the maximum stresses within the fuselage, subject to strain constraint in conjunction with both geometry and choice of appropriate fibre orientations and stacking sequence as design variables and also material parameters. The fuselage for the UAV plane was designed and manufactured using E-Glass/Epoxy and High modulus (HM) carbon/Epoxy composites. In this paper ANSYS software has been successfully applied to minimize the weight of the fuselage and increase the UAV fuselage strength. The results show how the fuselage design could be improved with the help of finite element method analysis and provide guidelines for the structure and material design for the composite based UAV SWAN fuselage.

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.

Simplified Model for the Weight Estimation of Floating Offshore Plant Using the Statistical Method

2014 ◽  
Author(s):  
Myung-Il Roh ◽  
Seong-Ho Seo ◽  
Hyun-Kyoung Shin ◽  
Nam-Kug Ku ◽  
Sol Ha ◽  
...  
Keyword(s):  
Statistical Method ◽  
Production Method ◽  
Simplified Model ◽  
Design Stage ◽  
Production Data ◽  
Weight Estimation ◽  
Important Data ◽  
Early Design Stage ◽  
Key Factor ◽  
Production Period

The weight information of a floating offshore plant, such as an FPSO, is one of the important data to estimate the amount of production material and to determine the production method for its construction. In addition, the weight information is a key factor which affects in the building cost and production period of the offshore plant. Although the importance of the weight has long been recognized, the weight has been roughly estimated by using the existing design and production data, and designer’s experience. To improve this task, a simplified model for the weight estimation of the offshore plant using the statistical method was developed in this study. To do this, various past records to estimate the weight of the offshore plant were collected through the literature survey, and then the correlation analysis and the multiple regression analysis were performed to develop the simplified model for the weight estimation. Finally, to evaluate the applicability of the developed model, it was applied to some examples of the weight estimation of topsides of the offshore plant. The results showed that the developed model can be applied the weight estimation process of the offshore plant at the early design stage.

An Approach for Assessing Fuel Assembly’s Structural Integrity Under In-Core Operating Conditions Using Finite Element Method

2009 ◽  
Author(s):  
Wei Zhao ◽  
Yuriy Aleshin
Keyword(s):  
Finite Element ◽  
Lateral Load ◽  
Operating Conditions ◽  
Growth Effect ◽  
Structural Behavior ◽  
Design Stage ◽  
Structural Components ◽  
Early Design ◽  
Early Design Stage ◽  
Spring Force

This paper describes the development and application of a single fuel assembly (FA) finite element analysis (FEA) model that can be used to assess and predict the structural behavior of FA during its entire life at early design stage. This model includes all structural components of a FA and has been validated under laboratory test conditions, including spacer grid test under axial load, skeleton test under axial and lateral load, FA test under axial and lateral load, as well as the fuel rod drag test. The model is then applied to an example FA design by predicting the FA’s in-core behavior, including its growth characteristics due to irradiation, and irradiation-induce creep and hydrogen absorption; effect of spring force relaxation of structural spacer grids; effect of holddown spring force increase with growth; effect of different amounts of initial FA bow and bowed shapes; FA distortion evolution vs. burnup history; and stress and deformation of various structural components. It demonstrates that this approach can be used to assess fuel assembly’s structural behavior under various operating conditions at early design stage.

Concurrent Topology Optimization of Lightweight Cellular Materials and Structures

2017 ◽  
Vol 868 ◽  
pp. 291-296
Author(s):  
He Ting Qiao ◽  
Shi Jie Wang ◽  
Xiao Ren Lv
Keyword(s):  
Topology Optimization ◽  
Material Design ◽  
Cellular Materials ◽  
Cellular Material ◽  
Design Stage ◽  
Concurrent Design ◽  
Design Variables ◽  
Macro Scale ◽  
Optimum Topology ◽  
Two Stages

In this paper, a two-stage optimization algorithm is proposed to simultaneously achieve the optimum structure and microstructure of lightweight cellular materials. Microstructure is assumed being uniform in macro-scale to meet manufacturing requirements. Furthermore, to reduce the computation cost, the design process is divided into two stages, which are concurrent design and material design. In the first stage, macro density and modulus matrix of cellular material are used both as design variables. Then, the optimum topology of macro-structure and modulus matrix of cellular materials will be obtained under this configuration. In the second stage, topology optimization technology is used to achieve a micro-structure of cellular material which is corresponded with the optimum modulus matrix in the earlier concurrent design stage. Moreover, the effectiveness of the present design methodology and optimization scheme is then demonstrated through numerical example.

Predicting Average Product Lifetime Using Physics-Based Gaussian Process Method in Early Design Stage

2020 ◽  
Author(s):  
Xinpeng Wei ◽  
Daoru Han ◽  
Xiaoping Du
Keyword(s):  
Gaussian Process ◽  
Gaussian Process Regression ◽  
Design Stage ◽  
Average Lifetime ◽  
Small Data ◽  
Time To Failure ◽  
Early Design ◽  
Early Design Stage ◽  
Design Variables ◽  
Lifetime Testing

Abstract Average lifetime, or mean time to failure (MTTF), of a product is an important metric to measure the product reliability. Current methods of evaluating MTTF are mainly statistics or data based. They need lifetime testing on a number of products to get the lifetime samples, which are then used to estimate MTTF. The lifetime testing, however, is expensive in terms of both time and cost. The efficiency is also low because it cannot be effectively incorporated in the early design stage where many physics-based models are available. We propose to predict MTTF in the design stage by means of physics-based models. The advantage is that the design can be continually improved by changing design variables until reliability measures, including MTTF, are satisfied. Since the physics-based models are usually computationally demanding, we face a problem with both big data (on the model input side) and small data (on the model output side). We develop an adaptive supervised training method based on Gaussian process regression, and the method can then quickly predict MTTF with minimized number of calling the physics-based models. The effectiveness of the method is demonstrated by two examples.

Design Space Analysis Method for Support of System Design Under the Consideration of Uncertainties in the Early Design Stage

2020 ◽  
Author(s):  
Kazuhiro Aoyama ◽  
Yoshihiro Uchibori ◽  
Kazuya Oizumi ◽  
Shigeki Hiramatsu ◽  
Hiroshi Unesaki ◽  
...  
Keyword(s):  
System Design ◽  
Design Space ◽  
Solution Space ◽  
Design Stage ◽  
Design Solution ◽  
Analysis Method ◽  
Early Design Stage ◽  
Design Variables ◽  
Full Picture ◽  
Set Based Design

Abstract In this study, following the concept of set-based design, after preparing global calculation results, we introduced the approach of setting the design solution area that satisfies the product performance goals of the system design. In this approach, from the viewpoint of considering uncertainty, we aimed to develop an analysis method that can get the organic relationship between target variables and design variables. And more, under the assumption that it is difficult to comprehend the full picture of products that are becoming more sophisticated and complex with the knowledge that has been fostered by skilled engineers, the proposed system uses the objective calculation indices that is provided knowledge of the designer. Specifically, the following method are proposed to solve the problem. - Implementation of meta-modeling of design space. - Classified solution space using a density-based clustering method to detect that the solution spaces are divided into multiple disconnected space. - Defined an index called distribution concentration and expressed the possibility of dealing with the uncertainty of the solution domain. - The network diagram based on the calculated index values was proposed to confirm the change in the characteristics of the solution space when the performance target of the product was changed. Finally, the effectiveness of the proposed method was verified by applying it to actual simulation results.

Combined Approximation Reanalysis Coupled With Finite Element Stress Analysis for Multiple Geometric Changes in Early Design Stage

2005 ◽  
Author(s):  
Sachin S. Terdalkar ◽  
Joseph J. Rencis
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Design Stage ◽  
Finite Element Technique ◽  
Early Design ◽  
Early Design Stage ◽  
Machine Element ◽  
Element Technique ◽  
Geometric Changes

In this work a new graphically driven interactive stress reanalysis finite element technique has been developed so that an engineer can easily carry out manual geometric changes in a machine element during the early design stage. The interface allow an engineer to model a machine element in the commercial finite element code ANSYS® and then modify part geometry graphically to see instantaneous graphical changes in the stress and displacement contour plots. A reanalysis technique is used to enhance the computational performance for solving the modified problem; with the aim of obtaining results of acceptable accuracy in as short a period of time in order to emphasize the interactive nature of the design process. Two case studies are considered to demonstrate the effectiveness of the prototype graphically driven reanalysis finite element technique. The finite element type considered is a plane stress four-node quadrilateral based on a homogenous, isotropic, linear elastic material. Each case study considered multiple redesigns. A combined approximation reanalysis method is used to solve each redesigned problem. The first case study considers a plate with a hole with the goal to determine the hole shape that will minimize the stress concentration. The second case study considers a support bracket. The goal is to design the cantilever portion of the bracket to have uniform strength and to minimize the stress concentration at the fillet.

scholarly journals A Consistent Procedure Using Response Surface Methodology to Identify Stiffness Properties of Connections in Machine Tools

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1220 ◽  
Author(s):  
Jesus-Maria Hernandez-Vazquez ◽  
Iker Garitaonandia ◽  
María Fernandes ◽  
Jokin Muñoa ◽  
Luis Lacalle
Keyword(s):  
Finite Element ◽  
Response Surface ◽  
Machine Tools ◽  
Computational Cost ◽  
Fractional Factorial ◽  
Dynamic Responses ◽  
Design Stage ◽  
Design Parameters ◽  
Regression Equations ◽  
Design Variables

Accurate finite element models of mechanical systems are fundamental resources to perform structural analyses at the design stage. However, uncertainties in material properties, boundary conditions, or connections give rise to discrepancies between the real and predicted dynamic characteristics. Therefore, it is necessary to improve these models in order to achieve a better fit. This paper presents a systematic three-step procedure to update the finite element (FE) models of machine tools with numerous uncertainties in connections, which integrates statistical, numerical, and experimental techniques. The first step is the gradual application of fractional factorial designs, followed by an analysis of the variance to determine the significant variables that affect each dynamic response. Then, quadratic response surface meta-models, including only significant terms, which relate the design parameters to the modal responses are obtained. Finally, the values of the updated design variables are identified using the previous regression equations and experimental modal data. This work demonstrates that the integrated procedure gives rise to FE models whose dynamic responses closely agree with the experimental measurements, despite the large number of uncertainties, and at an acceptable computational cost.

A Numerical Investigation of the Mechanics of Swelling-Type Intramedullary Hip Implants

1997 ◽  
Vol 119 (3) ◽  
pp. 241-247 ◽  
Author(s):  
S. R. Kalidindi ◽  
P. Ahmad
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Material Design ◽  
Element Model ◽  
Material Behavior ◽  
Hip Implants ◽  
Material Development ◽  
Design Variables ◽  
Principal Axes

The novel concept of swelling-type intramedullary hip implants that attain self-fixation by an expansion-fit mechanism resulting from controlled swelling of the implant (by absorption of body fluids) was examined in detail using a finite element model of the implant-femur system. Some of the potential advantages of this technique over traditional techniques include enhanced fixation, lower relative micromotions, improved bony ingrowth, and elimination of acrylic cement. The finite element model created in this study incorporated: (i) the major aspects of the three-dimensional geometry of the implant and femur, (ii) the anisotropic elastic properties of bone and implant materials and the changes in orientation of the principal axes of anisotropy along the length of the implant-femur system, (iii) a layer of cancellous bone between the implant and cortical bone in the proximal femoral region, and (iv) frictional sliding between the bone and implant. The model was used to study quantitatively the parametric influence of various material design variables on the micromotions and stress fields in the bone-swelling-type implant system. The results of the finite element analyses were used to establish material behavior goals and provide targets for a material development study.

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