scholarly journals Towards the Design of a Multispar Composite Wing

Computation ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 24
Author(s):  
Dimitriοs Stamatelos ◽  
George Labeas
Keyword(s):  
Stress Analysis ◽  
Large Scale ◽  
Bolted Joints ◽  
Structure Stability ◽  
Composite Component ◽  
Structure Comparison ◽  
Analysis Methodology ◽  
Design Requirements ◽  
Wing Structure ◽  
Composite Wing

In the pursuit of a lighter composite wing design, fast and effective methodologies for sizing and validating the wing members (e.g., spar, ribs, skins, etc.) are required. In the present paper, the preliminary design methodology of an airliner main composite wing, which has an innovative multispar configuration instead of the conventional two-spar design, is investigated. The investigated aircraft wing is a large-scale composite component, requiring an efficient analysis methodology; for this purpose, the initial wing sizing is mostly based on simplified Finite Element (FE) stress analysis combined to analytically formulated design criteria. The proposed methodology comprises three basic modules, namely, computational stress analysis of the wing structure, comparison of the stress–strain results to specific design allowable and a suitable resizing procedure, until all design requirements are satisfied. The design constraints include strain allowable for the entire wing structure, stability constraints for the upper skin and spar webs, as well as bearing bypass analysis of the riveted/bolted joints of the spar flanges/skins connection. A comparison between a conventional (2-spar) and an innovative 4-spar wing configuration is presented. It arises from the comparison between the conventional and the 4-spar wing arrangement, that under certain conditions the multispar configuration has significant advantages over the conventional design.

HALE UAV Composite Wing Structure Design

2010 ◽  
Vol 123-125 ◽  
pp. 105-108
Author(s):  
Myoung Keon Lee ◽  
Chang Min Cho ◽  
Se Yong Jang
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Composite Structure ◽  
Buckling Analysis ◽  
Design Parameters ◽  
Critical Design ◽  
Design Requirements ◽  
Wing Structure ◽  
Long Endurance ◽  
Composite Wing

HALE (High Altitude Long Endurance) UAVs are aircraft systems for surveillance and reconnaissance for over 25 hours. Most of UAVs consist of fuselage and high aspect ratio wing because of long-endurance flight mission. The structural weight of HALE UAV is one of the most critical design requirements. In addition, the structural stiffness for the high aspect ratio wing is another critical design requirement because the UAV has to keep the minimum clearance between wing tip and ground when the UAV is being towed. For above design requirements, the wing structure of the UAV has been designed by intermediate modulus Gr/Ep composite materials. The goal of this research is to present the optimized design concepts for the composite wing structure of the UAV. Although there are many design parameters for the composite structure of the aircraft, this research is focused on composite structure strength and buckling analysis for the plate type structures, such as cover panel skins and spar webs, which are loaded in in-plane shear and/or compression. This research presents that the wing structural weight can be reduced when the material allowables based on tape laminate are applied instead of unidirectional lamina allowables. For the buckling analysis, this report has a trade off study to find an optimized lay-up design and stacking sequence with 0°, ±45° and 90° plies. This research shows that the critical buckling load is a function of the number of ±45° plies and the position of the ±45° plies through the laminate thickness using a typical Gr/Ep composite tape material. The structural design of the UAV composite wing regarding buckling analysis is more effective when the laminates are stacked up with high percent of ±45° plies and the ±45° plies are located toward outside through the laminate.

Selection of the Optimal Structural Design of a Spar Composite Wing

2021 ◽  
pp. 90-99
Author(s):  
O.V. Tatarnikov ◽  
W.A. Phyo ◽  
Lin Aung Naing
Keyword(s):  
Optimal Design ◽  
Element Analysis ◽  
Minimal Weight ◽  
Wing Structures ◽  
Optimization Parameters ◽  
Nonlinear Static ◽  
Wing Structure ◽  
Pareto Method ◽  
Selection Of ◽  
Composite Wing

This paper describes a method for optimizing the design of a spar-type composite aircraft wing structure based on multi-criterion approach. Two types of composite wing structures such as two-spar and three-spar ones were considered. The optimal design of a wing frame was determined by the Pareto method basing on three criteria: minimal weight, minimal wing deflection, maximal safety factor and minimal weight. Positions of wing frame parts, i.e. spars and ribs, were considered as optimization parameters. As a result, an optimal design of a composite spar-type wing was proposed. All the calculations necessary to select the optimal structural and design of the spar composite wing were performed using nonlinear static finite element analysis in the FEMAP with NX Nastran software package.

Elasto-Plastic Stress Analysis Methodology Establishment for Forging Dies

2018 ◽  
Author(s):  
Dattaprasad P. Lomate ◽  
Govind Jagtap ◽  
Abhijit Patil ◽  
Sanket Inamdar ◽  
Rajkumar Singh ◽  
...  
Keyword(s):  
Stress Analysis ◽  
Analysis Methodology ◽  
Plastic Stress

An Efficient Re-Analysis Methodology for Vibration of Large-Scale Structures

2007 ◽  
Author(s):  
Geng Zhang ◽  
Zissimos P. Mourelatos ◽  
Efstratios Nikolaidis
Keyword(s):  
Large Scale ◽  
Large Scale Structures ◽  
Analysis Methodology ◽  
Scale Structures

scholarly journals On the characteristics of bolted joints with gaskets (Stress analysis of metal gaskets for raised face interposed between pipe flanges)

1985 ◽  
Vol 51 (466) ◽  
pp. 1587-1596 ◽  
Author(s):  
Toshiyuki SAWA ◽  
Hiroyuki KUMANO ◽  
Hirofumi IWAKAWA
Keyword(s):  
Stress Analysis ◽  
Bolted Joints

Developing Reliable Measures

2021 ◽  
pp. 113-154
Author(s):  
Duane F. Alwin
Keyword(s):  
Measurement Errors ◽  
Large Scale ◽  
Longitudinal Design ◽  
Time Inconsistency ◽  
Survey Questions ◽  
Design Requirements ◽  
Panel Studies ◽  
Definition Of ◽  
Composite Variables ◽  
Over Time

This chapter presents a general approach to assessing the reliability of measurement of survey questions—those in common use in many surveys. The approach, which relies on a robust set of longitudinal design requirements, applies the quasi-Markov simplex model to multi-wave data in the evaluation of measurement errors for survey questions. Under particular assumptions, this model produces a set of estimates that conform to the psychometric definition of measurement reliability, defined as the ratio of true variance to observed variance. These models attribute some of the over-time inconsistency in measurements to unreliability and some to true change. This strategy rejects traditional notions of reliability that rely on internal consistency estimates for composite variables, as well as the simple test–retest approach to estimating reliability. Rather, the emphasis is on the separation of unreliability from true change in observations made over time. The importance of meeting several design requirements for using these over-time statistical models is also emphasized. These include the use of large-scale panel studies representative of known populations, with a minimum of three waves of measurement, separated by lengthy re-interview intervals, and limited to exactly replicated questions over the multiple waves. Results are presented from several three-wave panel studies that have employed this design, which provide evidence for the utility of the approach in the evaluation of the quality of survey measurement with respect to question content, context, and form.

scholarly journals Surface toughening – An industrial approach to increase the robustness of pure adhesive joints with film adhesives

2020 ◽  
Vol 234 (13) ◽  
pp. 1980-1987
Author(s):  
MJ Schollerer ◽  
J Kosmann ◽  
D Holzhüter ◽  
C Bello-Larroche ◽  
C Hühne
Keyword(s):  
Large Scale ◽  
Adhesive Bonding ◽  
Bolted Joints ◽  
Small Scale ◽  
Bonded Joints ◽  
Fiber Reinforced ◽  
Load Path ◽  
Stress Concentrations ◽  
Manufacturing Defects ◽  
Wide Range

Bonding is known for its wide range of advantages over bolted joints when joining different materials together. However, the advantages e.g. of homogeneous load distribution can quickly be lost in case of overload. For this reason, the load occurring in the adhesive is reduced by constructive measures far below the yield stress of the adhesive, which leads to a conservative joint design. And to be on the safe side, a few “chicken rivets” are then placed again. This problem is particularly well known in aviation. Highly loaded components are structurally bonded by a combination of rivets and adhesive in order to underline the advantages of structural adhesive bonding with the safety of the well-known bolted joints. Known as fail-safe design, this concept is damage tolerant and more robust against manufacturing defects through a secured double load path.  Especially when joining fiber-reinforced composites, bolts weaken the adherends of the joint and only contribute to load transfer when the brittle adhesive fails. With the help of Surface Toughening, a boltless technique for reducing stress concentrations and arresting cracks in adhesive bonded joints is available. This work describes the industrial application of this technique. Starting with coupon tests and a small scale demonstrator to ensure the compatibility with industrial manufacturing processes, such as infusion and prepreg manufacturing, a large scale demonstrator of a 2 m carbon fiber reinforced plastic (CFRP) - HTP leading edge with hybrid laminar flow control is manufactured by the industrial partner AERnnova. Verifying a simple and cost-effective application of the technology, Surface Toughening enables robust bonded joints with a minimum impact on today's process of adhesive bonding.

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