scholarly journals Wing Structure of the Next-Generation Civil Tiltrotor: From Concept to Preliminary Design

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 102
Author(s):  
Marika Belardo ◽  
Aniello Daniele Marano ◽  
Jacopo Beretta ◽  
Gianluca Diodati ◽  
Mario Graziano ◽  
...  
Keyword(s):  
Optimal Solution ◽  
Element Model ◽  
Preliminary Design ◽  
Next Generation ◽  
Software Environment ◽  
Reference Vehicle ◽  
Starting Point ◽  
Engineering Models ◽  
Wing Structure ◽  
Manufacturing Assembly

The main objective of this paper is to describe a methodology to be applied in the preliminary design of a tiltrotor wing based on previously developed conceptual design methods. The reference vehicle is the Next-Generation Civil Tiltrotor Technology Demonstrator (NGCTR-TD) developed by Leonardo Helicopters within the Clean Sky research program framework. In a previous work by the authors, based on the specific requirements (i.e., dynamics, strength, buckling, functional), the first iteration of design was aimed at finding a wing structure with a minimized structural weight but at the same time strong and stiff enough to comply with sizing loads and aeroelastic stability in the flight envelope. Now, the outcome from the first design loop is used to build a global Finite Element Model (FEM), to be used for a multi-objective optimization performed by using a commercial software environment. In other words, the design strategy, aimed at finding a first optimal solution in terms of the thickness of composite components, is based on a two-level optimization. The first-level optimization is performed with engineering models (non-FEA-based), and the second-level optimization, discussed in this paper, within an FEA environment. The latter is shown to provide satisfactory results in terms of overall wing weight, and a zonal optimization of the composite parts, which is the starting point of an engineered model and a detailed FEM (beyond the scope of the present work), which will also take into account manufacturing, assembly, installation, accessibility and maintenance constraints.

Lightweight Design of a Brake Caliper

2013 ◽  
Author(s):  
Federico Maria Ballo ◽  
Massimiliano Gobbi ◽  
Giampiero Mastinu ◽  
Amir Pishdad
Keyword(s):  
Cross Sections ◽  
Lightweight Design ◽  
Optimal Solution ◽  
Element Model ◽  
Industrial Applications ◽  
Structural Topology ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Beam Elements ◽  
Starting Point

As lightweight design assumes greater importance in road vehicles development, the present paper is mainly devoted to the structural optimization of a brake caliper. In the first part of the study a simplified finite element model based on beam elements of a brake caliper has been developed and validated. By using the developed model, a multi-objective optimization has been completed. The total mass of the caliper and the deformations at some critical locations have been minimised. The considered design variables are related to the shape of the caliper and the cross sections of the beam elements. The obtained optimal solutions are characterized by an asymmetric shape of the caliper. Optimised symmetric shapes currently used have been compared with the asymmetric ones in terms of performance. In the second part of the study, a detailed analysis on the optimal caliper shape has been carried out by performing a structural topology optimization. The minimum compliance problem has been solved using the SIMP (solid isotropic material with penalization) approach and the optimal solution has been compared with the ones obtained by applying the multi-objective optimization on the simplified model (beam elements). The obtained design solutions represent a good starting point for future developments in actual industrial applications.

Optimization Design of Composite Wing Structure of a Minitype Unmanned Aerial Vehicle

2010 ◽  
Vol 156-157 ◽  
pp. 1532-1536
Author(s):  
Yan Zhang ◽  
Fen Fen Xiong ◽  
Shu Xing Yang ◽  
Xiao Ning Mei
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Optimization Design ◽  
Optimal Solution ◽  
Element Model ◽  
Parametric Modeling ◽  
Aerial Vehicle ◽  
Wing Structure ◽  
Stain Analysis ◽  
Optimization Search ◽  
Composite Wing

The application of advanced composites on the aerocraft structure can significantly reduce the weight, and improve the aerodynamic and flight performances. In this work, optimization design of a composite wing structure of a minitype unmanned aerial vehicle (UAV) is implemented. The parametric finite element model is established using parametric modeling technique for stress and stain analysis. The global optimal solution is guaranteed by the proposed two-step optimization search strategy combing genetic algorithm (GA) and sequential quadratic programming (SQP).

Preliminary design of precast, segmental box-girder bridges using optimization

1979 ◽  
Vol 6 (1) ◽  
pp. 120-128
Author(s):  
Craig J. Miller ◽  
Juarez Accioly
Keyword(s):  
Minimum Cost ◽  
Preliminary Design ◽  
Box Girder Bridges ◽  
Cross Sectional ◽  
Box Girder ◽  
Prestressing Steel ◽  
Girder Bridges ◽  
Starting Point ◽  
Final Design ◽  
The Cost

Precast, prestressed segmental box-girder bridges are now accepted as an economical alternative for spans over 150 ft (46 m). Decisions about cross-sectional dimensions made during preliminary design can have a substantial influence on the final cost of the bridge. To help the designer obtain an economical starting point for a final design, a program was written to determine section dimensions and midspan and pier prestressing steel areas to give minimum cost. Since a preliminary design is obtained, the analysis techniques and design criteria have been simplified to reduce computation. The design produced by the program will satisfy AASHTO specification requirements and the recommendations of the PCI Bridge Committee. The optimization algorithm used is the generalized reduced gradient technique. To demonstrate the program capabilities, three example problems are discussed. The results indicate that optimum span-depth ratios are approximately 24 for the cost ratios used. The cost of the optimum design does not seem to be too sensitive to the ratio of concrete cost to prestressing steel cost.

Preliminary Design of Variable Nozzle Turbines Based on Sensitive Parameters

2020 ◽  
Author(s):  
Sebastian Wittwer ◽  
Ivo Sandor
Keyword(s):  
Engine Performance ◽  
Optimal Solution ◽  
Operating Conditions ◽  
Experimental Results ◽  
Preliminary Design ◽  
Component Level ◽  
Gasoline Engines ◽  
Functional Parameters ◽  
Predictive Quality ◽  
Recent Developments

Abstract Recent developments in turbocharged gasoline engines have established new requirements for the turbine. A simple approach of scaling or optimizing existing turbines on component level might not be sufficient in terms of finding an optimal solution according to the multi-point, multi-disciplinary layout target. In the following paper nondimensional functional parameters are derived from turbomachinery analytics and rated on corresponding values of existing turbine stages. The influence of different parameters on aerodynamic performance is discussed based on CFD results and arranged according to their sensitivity for different engine relevant operating conditions. A metamodel for the preliminary design of variable nozzle turbine stages is derived from DoE (Design of Experiments) based CFD results. It is evaluated regarding its predictive quality on several exemplary turbine stages. Both, CFD and experimental results are therefore used while the experimental results are made up of hot gas stand measurements as well as measurements on engine test bench. Thus, not only the influence of functional parameters can be verified on turbine efficiency characteristics, but beyond that also the predictive quality of engine performance can be assessed.

Conceptualizing a New CMS Design

2011 ◽  
pp. 344-358
Author(s):  
Ali Jafari
Keyword(s):  
User Interface ◽  
Interface Design ◽  
Management System ◽  
User Interface Design ◽  
Course Management System ◽  
Degree Programs ◽  
Next Generation ◽  
Software Environment ◽  
Smart Services ◽  
Advanced Controls

This chapter discusses the characteristics and requirements for the Next Generation of Course Management System (CMS). The chapter begins with a survey of the current CMS systems elaborating on understanding the current CMS user interface design, understanding the next generation of CMS users, and understanding the forthcoming models for future courses and degree programs. The chapter concludes with painting a picture of the next generation of CMS software environment being characterized as offering smart services, featuring advanced controls, and offering comprehensive software environment.

Discontinuous failure in micropolar elastic-degrading models

2017 ◽  
Vol 27 (10) ◽  
pp. 1482-1515 ◽  
Author(s):  
Lapo Gori ◽  
Samuel S Penna ◽  
Roque L da Silva Pitangueira
Keyword(s):  
Material Model ◽  
Element Model ◽  
Additional Material ◽  
Micropolar Continuum ◽  
Starting Point ◽  
Localization Analysis ◽  
Acceleration Waves ◽  
Micropolar Media ◽  
Waves Propagation ◽  
Bending Length

The present paper investigates the phenomenon of discontinuous failure (or localization) in elastic-degrading micropolar media. A recently proposed unified formulation for elastic degradation in micropolar media, defined in terms of secant tensors, loading functions and degradation rules, is used as a starting point for the localization analysis. Well-known concepts on acceleration waves propagation, such as the Maxwell compatibility condition and the Fresnel–Hadamard propagation condition, are derived for the considered material model in order to obtain a proper failure indicator. Peculiar problems are investigated analytically in details, in order to evaluate the effects on the onset of localization of two of the additional material parameters of the micropolar continuum, the Cosserat’s shear modulus and the internal bending length. Numerical simulations with a finite element model are also presented, in order to show the regularization behaviour of the micropolar formulation on the pathological effects due to the localization phenomenon.

Structure Optimization Design for the Bed of Gear Hobbing Machine

2013 ◽  
Vol 765-767 ◽  
pp. 176-180
Author(s):  
Rong Chuang Zhang ◽  
Ao Xiang Liu ◽  
Jun Wang ◽  
Wan Shan Wang
Keyword(s):  
Optimization Design ◽  
Optimal Solution ◽  
Element Model ◽  
Weighting Coefficient ◽  
Design Parameters ◽  
Analytic Hierarchy ◽  
Design Variables ◽  
Gear Hobbing ◽  
Vibration Modal ◽  
Hierarchy Process

In the optimization design of the gear hobbing machine bed, the finite element model is build and the static analysis and vibration modal analysis are performed. Then sensitivity analysis is used to gain the main design parameters which influence the bed property most. Furthermore, the multi-objective optimization design of the bed is performed in ANSYS Workbench with these design parameters as the design variables. At last, after all optimum proposals are showed up, Analytic Hierarchy Process is used to determine the weighting coefficient, and the most optimal solution is found out. As a result, the dynamic and static performances of the machine bed are improved under control of the machine bed mass.

A Discussion about Finite Element Analysis of Aircraft Wing Structure

2012 ◽  
Vol 532-533 ◽  
pp. 427-430
Author(s):  
Wei Tao Zhao ◽  
Tian Jun Yu ◽  
Yi Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aircraft Design ◽  
Element Model ◽  
Aircraft Wing ◽  
Element Analysis ◽  
Actual Structure ◽  
Shear Plate ◽  
Wing Structure ◽  
Lifting Surfaces

One of the most significant components of aircraft design is the wing, the wings are the main lifting surfaces that support the airplane in flight. The structures of wings must have enough strength and rigidity to ensure the safe of the aircraft. Usually, the displacements of the structures are calculated by using finite element method. But it is very difficult to select a reasonable finite element model to approximate the actual structure. In this study, two models are adopted to calculate the displacements of the wing structure. The first is a model of rod and shear plate, the second is a model of beam and shell. The disadvantages and advantages of two models are discussed. As seen from the comparison with the test date, two models proposed are both feasible to analyze the wing structure.

Numerical Simulation of Accumulative Forming Bipolar Plates of Fuel Cell

2010 ◽  
Vol 136 ◽  
pp. 10-13
Author(s):  
Zhen Ying Xu ◽  
Jing Jing Wang ◽  
Sheng Ding ◽  
Wu Wen ◽  
Yun Wang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Element Model ◽  
Bipolar Plate ◽  
Forming Limit ◽  
Bipolar Plates ◽  
Thickness Change ◽  
Flow Channels ◽  
Starting Point ◽  
Micro Flow ◽  
Maximal Magnitude

The bipolar plate is the key part in the fuel cell. It is difficult to produce the micro flow channel of bipolar plates with high accuracy. In order to solve this problem, we present one new forming techniques, accumulative forming, for the fabrication of micro flow channels. With the utilization of the software ABAQUS, finite element model of the bipolar plate with the 20mm×20mm×0.2mm is developed to simulate the accumulative forming and obtain the forming rules. The simulation results are about the plate’s thickness change and deformation. It shows that the thickness reduction decreases gradually from the center of the channel to the outside with the maximal magnitude in the starting point of accumulative forming. The maximum thinning ratio is 15.85%, which is in the forming limit scope. The simulation demonstrates the feasibility of the accumulative forming and good formability.

Assessment of Corner Failure Depths in the Deep Drawing of 3D Panels Using Simplified 2D Numerical and Analytical Models

2000 ◽  
Vol 123 (2) ◽  
pp. 248-257 ◽  
Author(s):  
Hong Yao ◽  
Jian Cao
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Analytical Models ◽  
Design Stage ◽  
Beam Model ◽  
Preliminary Design ◽  
Powerful Means ◽  
Preliminary Design Stage ◽  
Blank Size

Methodologies of rapidly assessing maximum possible forming heights are needed for three-dimensional 3D sheet metal forming processes at the preliminary design stage. In our previous work, we proposed to use an axisymmetric finite element model with an enlarged tooling and blank size to calculate the corner failure height in a 3D part forming. The amount of enlargement is called center offset, which provides a powerful means using 2D models for the prediction of 3D forming behaviors. In this work, an analytical beam model to calculate the center offset is developed. Starting from the study of a square cup forming, a simple analytical model is proposed and later generalized to problems with corners of an arbitrary geometry. The 2D axisymmetric models incorporated with calculated center offsets were compared to 3D finite element simulations for various cases. Good assessments of failure height were obtained.

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