scholarly journals Effects of Unbalanced Lamination Parameters on the Static Aeroelasticity of a High Aspect Ratio Wing

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
JinYang Li ◽  
JunLi Wang ◽  
ZhiGui Ren ◽  
WeiFeng Wei
Keyword(s):  
Structural Design ◽  
Composite Laminates ◽  
Constant Thickness ◽  
Loose Coupling ◽  
Linear Distribution ◽  
Static Aeroelasticity ◽  
Wing Structure ◽  
Coupling Calculation ◽  
The Relationship ◽  
Nonlinear Distribution

In this paper, in order to understand the influence of the unbalanced coefficient of composite laminates on the static aeroelasticity of high aspect wings, a series of numerical simulation calculations were carried out, and this work wants to provide some reference for the structural design of aircraft. Considering the influence of geometric nonlinearity, the unidirectional fluid-solid coupling calculation method based on loose coupling is used to control the change of unbalanced coefficient of laminates on the basis of layering angle, layering thickness, and layering region, so as to observe the changes caused to the wings. The relationship between the unbalanced coefficient and the constant thickness layup and the variable thickness layup with 0° and ±45° layup angles was studied, respectively. Then, the layup angle of 90° was added to study the influence of the unbalanced coefficient on the static aeroelasticity of the wing structure with the change of the layup angle and the different choice of layup region. The results show that the deformation is the smallest when the unbalanced coefficient is 0.5, and the deformation trend is evenly distributed along both sides when the unbalanced coefficient is 0.5. When the unbalanced coefficient is changed, adding the 90° layup angle can significantly reduce the overall deformation of the wing and show different sensitivity characteristics to different layup areas. The increase of the unbalanced coefficient makes the chordal displacement gradually change from linear distribution to nonlinear distribution along the spread direction, and the displacement will gradually decrease.

Joint fixity effect on structural design of a box wing aircraft

2012 ◽  
Vol 116 (1178) ◽  
pp. 363-372
Author(s):  
P. O. Jemitola ◽  
J. Fielding ◽  
P. Stocking
Keyword(s):  
Finite Element ◽  
Structural Design ◽  
Vortex Lattice ◽  
Computational Study ◽  
Requirements Analysis ◽  
Stress Distributions ◽  
Box Models ◽  
Wing Structure

Abstract A computational study was performed to compare the stress distributions in finite element torsion box models of a box wing structure that result from employing four different wing/end fin joint fixities. All considered wings were trimmed in pitch. The joint fixities refer to the type of attachment that connects the tip of the fore and aft wings to the end fin. Using loads from a vortex lattice tool, the analysis determined the best wing-joint fixity of a statically loaded idealised box wing configuration by comparing the stress distributions resulting from the different wing joints in addition to other essential aerodynamic requirements. Analysis of the wing joint fixity indicates that the rigid joint is the most suitable.

RELATIONSHIP OF MAXIMUM DEFLECTIONS AND NATURAL FREQUENCIES VIBRATIONS OF ISOTROPIC CIRCULAR PLATES WITH INHOMOGENEOUS RESISTANCE CONDITIONS ON THE OUTER AND INNER CONTOUR

2021 ◽  
Vol 98 (6) ◽  
pp. 36-42
Author(s):  
A.V. TURKOV ◽  
◽  
S.I. POLESHKO ◽  
E.A. FINADEEVA ◽  
K.V. MARFIN ◽  
...  
Keyword(s):  
Variable Thickness ◽  
Constant Thickness ◽  
Circular Plates ◽  
Outer Contour ◽  
Numerical Studies ◽  
The Difference ◽  
Relationship Of ◽  
The Relationship ◽  
Hinged Support ◽  
Natural Transverse

The relationship between the maximum deflections from a static uniformly distributed load W0 and the fundamental frequency of natural transverse vibrations of a round isotropic plate of linearly variable thickness with thickening to the edge under homogeneous conditions of support along the outer contour, depending on the ratio of the thickness of the plate in the center to the thickness along the edge, is considered. According to the results of the study, graphs of the dependence of the maximum deflection and the frequency of natural vibrations of the plate on the ratio t1 / t2 are constructed. It is shown that for round plates of linearly variable thickness at t1/t2<1.1 coefficient K with an accuracy of 5.9% coincides with the analytical coefficient for round plates of constant thickness. Numerical studies shows that when the ratio of the thicknesses on the contour and in the center is equal to two, the difference in the coefficient K, which depends on the relationship between the static and dynamic characteristics of the platinum, is about 25% for hinged support along the contour and up to 37% for rigid support. This indicates a more significant effect of uneven mass distribution for such boundary conditions.

How a participatory process with inclusive structural design allocates resources toward poor neighborhoods: the case of participatory budgeting in Seoul, South Korea

2020 ◽  
pp. 002085232094366
Author(s):  
Won No ◽  
Lily Hsueh
Keyword(s):  
South Korea ◽  
Public Participation ◽  
Structural Design ◽  
Organizational Structures ◽  
Participatory Process ◽  
Participatory Budgeting ◽  
The Public ◽  
The Government ◽  
Public Money ◽  
The Relationship

This study examines the relationship between inclusiveness with respect to the structural design of the participatory process and resource allocation outcomes in participatory budgeting. Empirically, this article examines the case of participatory budgeting in Seoul, South Korea, where redistribution is not an explicit goal. Findings suggest that creating organizational structures that enable and encourage public participation has led Seoul’s participatory budgeting to distribute public funds toward poor neighborhoods. Points for practitioners Participatory budgeting is an exemplar practice of public participation in the government decision-making process. It is a local budgeting practice that allows the public to participate, discuss, deliberate, and decide where and how to spend public money. This study highlights the importance of designing inclusive organizational structures in participatory budgeting to encourage public participation. Empirical results underscore the link between inclusive organizational structures and more equitable allocation outcomes.

Structural Design of the Geometrical Shape of Interfaces in Bonded Dissimilar Materials Based on Theoretical Elastic Analysis

1999 ◽  
Vol 586 ◽  
Author(s):  
Masayoshi Tateno ◽  
Yasushi Fukuzawa ◽  
Shigeru Nagasawa ◽  
Hiroshi Sakuta
Keyword(s):  
Stress Distribution ◽  
Structural Design ◽  
Bonding Strength ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
Correlation Factor ◽  
Geometrical Shape ◽  
Elastoplastic Behavior ◽  
Secant Stiffness ◽  
The Relationship

ABSTRACTIn order to evaluate the practical strength of a joint and its fracture mode, it is important to find the stress distribution near the edge of the interface by analyses of strength and fracture. The index of stress singularity based on theoretical analysis is a useful tool to indicate the stress distribution.In this paper, investigations on the evaluation of the practical strength of bonded dissimilar materials based on the stress singularity are carried out. The secant stiffness module, which was used for plastics analysis, was applied to the evaluation of thermal elastoplastic behavior near the interface. Spherical conditions of the interface shape were used for the evaluation of stress behavior and the experiment of bonding strength. The relationship between the index of stress singularity, λ, and the practical strength of the bonded TiB2-Ni system was investigated by comparing theoretical λ, which was determined by substituting the secant stiffness module into Bogy's eigenequation, with the practical strength in the edge angle of the interface between 60° and 90° The correlation factor of the relationship between λ and the practical bonding strength of the TiB2-Ni system was found positive. These results show that the structural design of a geometrical interface which is getting a higher strength joint based on the index of stress singularity is verified experimentally.

scholarly journals Topologically associated domains enriched for lineage-specific genes reveal expression-dependent nuclear topologies during myogenesis

2016 ◽  
Vol 113 (12) ◽  
pp. E1691-E1700 ◽  
Author(s):  
Daniel S. Neems ◽  
Arturo G. Garza-Gongora ◽  
Erica D. Smith ◽  
Steven T. Kosak
Keyword(s):  
Gene Regulation ◽  
Genome Organization ◽  
Spatial Organization ◽  
Potential Role ◽  
Spatial Distance ◽  
Linear Distribution ◽  
Myotube Formation ◽  
Topologically Associated Domains ◽  
The Relationship ◽  
Lineage Specific Genes

The linear distribution of genes across chromosomes and the spatial localization of genes within the nucleus are related to their transcriptional regulation. The mechanistic consequences of linear gene order, and how it may relate to the functional output of genome organization, remain to be fully resolved, however. Here we tested the relationship between linear and 3D organization of gene regulation during myogenesis. Our analysis has identified a subset of topologically associated domains (TADs) that are significantly enriched for muscle-specific genes. These lineage-enriched TADs demonstrate an expression-dependent pattern of nuclear organization that influences the positioning of adjacent nonenriched TADs. Therefore, lineage-enriched TADs inform cell-specific genome organization during myogenesis. The reduction of allelic spatial distance of one of these domains, which contains Myogenin, correlates with reduced transcriptional variability, identifying a potential role for lineage-specific nuclear topology. Using a fusion-based strategy to decouple mitosis and myotube formation, we demonstrate that the cell-specific topology of syncytial nuclei is dependent on cell division. We propose that the effects of linear and spatial organization of gene loci on gene regulation are linked through TAD architecture, and that mitosis is critical for establishing nuclear topologies during cellular differentiation.

Spiral Flow Capability Research in the Rotary Cylinder

2011 ◽  
Vol 103 ◽  
pp. 209-213
Author(s):  
Song Bai Li ◽  
Yi Lun Liu
Keyword(s):  
Flow Rate ◽  
Structural Design ◽  
Simple Algorithm ◽  
Inlet Pressure ◽  
Maximum Temperature ◽  
Radial Clearance ◽  
Interior Flow ◽  
Relationship Of ◽  
The Relationship ◽  
Laminar Flow Model

In order to obtain the lubricating capabilityof screw rotary cylinder, its structural design and operation principle were introduced. Seven screw pairs with different radial clearance were designed. The models were built by Pro/E. Structure mesh was generated by using Gambit. Based on laminar flow model and SIMPLE algorithm, the interior flow field in different radial clearances and the same radial clearance at different inlet pressure were numerically simulated and analyzed with Fluent. The relationship of loading force, stiffness, maximum temperature, flow rate and radial clearance were obtained. Simulation results show that the performance of oil lubricated screw pair is the best at the radial clearance of 0.10 mm. At the same radial clearance, when back pressure is constant, with inlet pressure increasing, loading force, stiffness, flow rate and maximum temperature increase completely.

Temperature Gradient of Concrete Pavement Slab Overlaid with Asphalt Surface Course

2000 ◽  
Vol 1730 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Tatsuo Nishizawa ◽  
Shigeru Shimeno ◽  
Akinori Komatsubara ◽  
Masashi Koyanagawa
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Stress ◽  
Temperature Gradient ◽  
Numerical Simulations ◽  
Structural Design ◽  
Concrete Slab ◽  
Concrete Pavement ◽  
Reduction Effect ◽  
The Relationship

In the structural design of composite pavement with a concrete pavement slab overlaid with an asphalt surface course, it is very important to estimate the temperature gradient in the concrete slab. An asphalt surface course reduces the temperature gradient in an underlaid concrete slab, resulting in the reduction of thermal stress of the concrete slab. This effect was investigated by temperature measurement in model pavements and by thermal conductivity analysis. Thermal properties were estimated by a backanalysis by using measured temperatures over 1 year. From the numerical simulations varying the thickness of asphalt surface and concrete slab, the relationship between the reduction effect and the asphalt thickness was derived as a function of the thickness of asphalt surface course, which can be used in the structural design of the composite pavement.

scholarly journals Influence of Hydrothermal Ageing on the Residual Stresses and Mechanical Behavior of Carbon/Epoxy Composite Laminates

2014 ◽  
Vol 996 ◽  
pp. 958-963
Author(s):  
Zhong Meng Wen ◽  
Xiao Lu Gong
Keyword(s):  
Residual Stresses ◽  
Composite Laminates ◽  
Epoxy Composite ◽  
Hydrothermal Condition ◽  
Hole Drilling ◽  
Mechanical Behaviors ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method ◽  
The Relationship

In this work, the residual stresses for composite laminates [02/θ2]S determined by means of the incremental hole-drilling method with a formula to express the relationship between the residual stresses and the relaxed strains around the drilled hole. Then the ageing tests related to hydrothermal condition are carried out to analyze the influence on the residual stress redistributions and also on the mechanical behaviors of the carbon/epoxy laminates.

scholarly journals Reliability - safety set of structures

2001 ◽  
Vol 23 (4) ◽  
pp. 216-223
Author(s):  
Le Xuan Huynh ◽  
Do Van Binh
Keyword(s):  
Confidence Level ◽  
Structural Design ◽  
Load Factor ◽  
Inhomogeneous State ◽  
Numerical Examples ◽  
Research Results ◽  
Random Models ◽  
Two Factors ◽  
Material Factor ◽  
The Relationship

Based on the results of A. D. Rzanitsin and V. D. Raizer in the references of [1] and [2], this paper gives other definitions of the confidence level of subjected loads βs and the confidence level of the strength of materials βR, then studies the relationship between the load factor k, the material factor m and the safety factor n in the traditional models with the factors of βs, βR and βs in the random models in the structural design. The research results show that physical meaning of two factors of βs, βR is the same as the factors of k and m, however it gives more clearly assessments on effects of the over load state and the material inhomogeneous state of the safety working state of the structures. Since the reliability - safety set is also determined from the research results. Some numerical examples are carried out to show the relationship between these above factors. 

scholarly journals Soft curvature sensors for measuring the rotational angles of mechanical fingers

2020 ◽  
Vol 15 (4) ◽  
pp. 610-621
Author(s):  
Haixiao Liu ◽  
Li Li ◽  
Zhikang Ouyang ◽  
Wei Sun
Keyword(s):  
Structural Design ◽  
High Sensitivity ◽  
Main Body ◽  
Sensing Element ◽  
Soft Sensors ◽  
Working Principle ◽  
The Relationship ◽  
Design Experiments ◽  
Mechanical Finger ◽  
Rubber Plate

AbstractThe design, fabrication, and testing of soft sensors that measure elastomer curvature and mechanical finger bending are described in this study. The base of the soft sensors is polydimethylsiloxane (PDMS), which is a translucent elastomer. The main body of the soft sensors consists of three layers of silicone rubber plate, and the sensing element is a microchannel filled with galliumindium-tin (Ga-In-Sn) alloy, which is embedded in the elastomer. First, the working principle of soft sensors is investigated, and their structure is designed. Second, the relationship between curvature and resistance is determined. Third, several sensors with different specifications are built in accordance with the structural design. Experiments show that the sensors exhibit high accuracy when the curvature changes within a certain range. Lastly, the soft sensors are applied to the measurement of mechanical finger bending. Experiments show that soft curvature sensors can effectively reflect mechanical finger bending and can be used to measure the bending of mechanical fingers with high sensitivity within a certain working range.

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