Shearing Deformation Research on Annular Woven Shaped Fabrics

2013 ◽  
Vol 821-822 ◽  
pp. 1175-1179
Author(s):  
He Chun Chen
Keyword(s):  
Shear Deformation ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Theory Model ◽  
Pressure Vessels ◽  
Woven Fabric ◽  
Theoretical Formula ◽  
Deformation Model ◽  
Theoretical Derivation ◽  
Fabric Shear

shaped weaving is a method which using unequal length of the warp and weft to weave shaped fabrics on the ordinary weaving frames. After multi-layer wound and resin solidified, these shaped fabrics can be formed into whole three-dimensional preform parts, such as oval-shaped pressure vessels, conical tube, ring, etc. because the batch roller on frame is cone frustum, not cylinder, which makes the shear deformation happens when tuck-in fabrics. In this paper, through the establishment of shear deformation model of the annular shaped woven fabric, and theoretical derivation on shear deformation, then calculate the weft deformation angle by theoretical formula. By contrast, we found the calculated shear deformation angle is very near to that measured on the shape fabrics. This proves the shear deformation model and theoretical derivation are correct, accord with the real situation of the shear deformation. Key words: shape woven fabric, shear deformation, theory model,shear angle

Structural Optimization of Woven Fabric with Curved Surface

2012 ◽  
Vol 443-444 ◽  
pp. 408-411
Author(s):  
Yan Fang Wang ◽  
Xing Feng Guo
Keyword(s):  
Structural Optimization ◽  
Shear Deformation ◽  
Three Dimensional ◽  
Single Layer ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Curved Surface ◽  
Theoretical Formula ◽  
Curved Surfaces

The woven fabric with curved surfaces is a kind of single layer woven fabrics, which was produced to smoothly fit three-dimensional solids. The warp or weft of the winding fabric bend were normally made with different lengths, which may result in shear deformation in many cases and accordingly twisting the structure of the fabric after fitted onto the solid. In order to solve the problem mentioned above, a theoretical formula was used to calculate the optimal intervals of the pick-spacing and an improved structure thus was developed in this study.

A refined quasi-3D shear deformation theory for thermo-mechanical behavior of functionally graded sandwich plates on elastic foundations

2017 ◽  
Vol 21 (6) ◽  
pp. 1906-1929 ◽  
Author(s):  
Abdelkader Mahmoudi ◽  
Samir Benyoucef ◽  
Abdelouahed Tounsi ◽  
Abdelkader Benachour ◽  
El Abbas Adda Bedia ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Shear Deformation ◽  
Elastic Foundation ◽  
Deformation Theory ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Sandwich Plates ◽  
Refined Theory ◽  
Governing Equations

In this paper, a refined quasi-three-dimensional shear deformation theory for thermo-mechanical analysis of functionally graded sandwich plates resting on a two-parameter (Pasternak model) elastic foundation is developed. Unlike the other higher-order theories the number of unknowns and governing equations of the present theory is only four against six or more unknown displacement functions used in the corresponding ones. Furthermore, this theory takes into account the stretching effect due to its quasi-three-dimensional nature. The boundary conditions in the top and bottoms surfaces of the sandwich functionally graded plate are satisfied and no correction factor is required. Various types of functionally graded material sandwich plates are considered. The governing equations and boundary conditions are derived using the principle of virtual displacements. Numerical examples, selected from the literature, are illustrated. A good agreement is obtained between numerical results of the refined theory and the reference solutions. A parametric study is presented to examine the effect of the material gradation and elastic foundation on the deflections and stresses of functionally graded sandwich plate resting on elastic foundation subjected to thermo-mechanical loading.

Two-discrete-elements concrete shear deformation model: Formulation and application in the seismic evaluation of reinforced concrete shear walls

2020 ◽  
Vol 23 (16) ◽  
pp. 3429-3445
Author(s):  
Fadi Oudah ◽  
Raafat El-Hacha
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Deformation ◽  
Axial Load ◽  
Shear Deformation Theory ◽  
Shear Walls ◽  
Shear Capacity ◽  
Complex Nature ◽  
Deformation Model ◽  
Discrete Elements

Shear deformation in reinforced concrete structures is of a complex nature. A thorough understanding of the interaction between the shear strength, flexural strength, and flexural ductility is not yet achieved. A new shear-deformation-based theory is proposed and validated in this study. The so-called two-discrete-elements (TDE) shear deformation theory idealizes reinforced concrete members as series of two discrete types of elements: S-elements and C-elements. The S-elements are used to model the regions of concrete reinforced to resist flexural and shear deformation using longitudinal and transverse steel reinforcement, while the C-elements are used to model the reinforced concrete sections bounded by the stirrups. The compatibility between the two types of elements is enforced by controlling the crack angle. The formulation of the newly developed theory is discussed in terms of equilibrium of forces, compatibility within the elements, compatibility at the interface, and constitutive material modeling. The theory was applied to evaluate the deformability of reinforced concrete shear walls subjected to lateral loads for seismic design applications. It was also implemented to generate sample design charts referred to as axial–moment–shear interaction diagrams. These diagrams can be used to design shear walls subjected to combined action of axial load, moment, and shear as opposed to the conventional interaction diagrams in which only the axial load versus moment relationship is considered. Analysis results indicated the adequacy of the proposed theory in capturing the shear strength degradation and predicting structural failures controlled by the shear capacity.

Enhanced First-Order Shear Deformation Theory for Laminated and Sandwich Plates

2005 ◽  
Vol 72 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Jun-Sik Kim ◽  
Maenghyo Cho
Keyword(s):  
Shear Deformation ◽  
Deformation Theory ◽  
Plate Theory ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Higher Order ◽  
Laminated Plates ◽  
Sandwich Plates ◽  
First Order ◽  
Transverse Shear Strains

A new first-order shear deformation theory (FSDT) has been developed and verified for laminated plates and sandwich plates. Based on the definition of Reissener–Mindlin’s plate theory, the average transverse shear strains, which are constant through the thickness, are improved to vary through the thickness. It is assumed that the displacement and in-plane strain fields of FSDT can approximate, in an average sense, those of three-dimensional theory. Relationship between FSDT and three-dimensional theory has been systematically established in the averaged least-square sense. This relationship provides the closed-form recovering relations for three-dimensional variables expressed in terms of FSDT variables as well as the improved transverse shear strains. This paper makes two main contributions. First an enhanced first-order shear deformation theory (EFSDT) has been developed using an available higher-order plate theory. Second, it is shown that the displacement fields of any higher-order plate theories can be recovered by EFSDT variables. The present approach is applied to an efficient higher-order plate theory. Comparisons of deflection and stresses of the laminated plates and sandwich plates using present theory are made with the original FSDT and three-dimensional exact solutions.

Refined First-Order Shear Deformation Theory Models for Composite Laminates

2003 ◽  
Vol 70 (3) ◽  
pp. 381-390 ◽  
Author(s):  
F. Auricchio ◽  
E. Sacco
Keyword(s):  
Shear Deformation ◽  
Analytical Solutions ◽  
Composite Laminates ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Quadratic Functions ◽  
Shear Stresses ◽  
Stress Profile ◽  
First Order ◽  
Out Of Plane

In the present work, new mixed variational formulations for a first-order shear deformation laminate theory are proposed. The out-of-plane stresses are considered as primary variables of the problem. In particular, the shear stress profile is represented either by independent piecewise quadratic functions in the thickness or by satisfying the three-dimensional equilibrium equations written in terms of midplane strains and curvatures. The developed formulations are characterized by several advantages: They do not require the use of shear correction factors as well as the out-of-plane shear stresses can be derived without post-processing procedures. Some numerical applications are presented in order to verify the effectiveness of the proposed formulations. In particular, analytical solutions obtained using the developed models are compared with the exact three-dimensional solution, with other classical laminate analytical solutions and with finite element results. Finally, we note that the proposed formulations may represent a rational base for the development of effective finite elements for composite laminates.

Derivation of Plate Theory Accounting Asymptotically Correct Shear Deformation

1997 ◽  
Vol 64 (4) ◽  
pp. 905-915 ◽  
Author(s):  
V. G. Sutyrin
Keyword(s):  
Shear Deformation ◽  
Asymptotic Method ◽  
Plate Theory ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Optimization Procedure ◽  
Laminated Plates ◽  
Orthotropic Plates ◽  
Variational Asymptotic ◽  
Variational Asymptotic Method

The focus of this paper is the development of linear, asymptotically correct theories for inhomogeneous orthotropic plates, for example, laminated plates with orthotropic laminae. It is noted that the method used can be easily extended to develop nonlinear theories for plates with generally anisotropic inhomogeneity. The development, based on variational-asymptotic method, begins with three-dimensional elasticity and mathematically splits the analysis into two separate problems: a one-dimensional through-the-thickness analysis and a two-dimensional “plate” analysis. The through-the-thickness analysis provides elastic constants for use in the plate theory and approximate closed-form recovering relations for all truly three-dimensional displacements, stresses, and strains expressed in terms of plate variables. In general, the specific type of plate theory that results from variational-asymptotic method is determined by the method itself. However, the procedure does not determine the plate theory uniquely, and one may use the freedom appeared to simplify the plate theory as much as possible. The simplest and the most suitable for engineering purposes plate theory would be a “Reissner-like” plate theory, also called first-order shear deformation theory. However, it is shown that construction of an asymptotically correct Reissner-like theory for laminated plates is not possible in general. A new point of view on the variational-asymptotic method is presented, leading to an optimization procedure that permits a derived theory to be as close to asymptotical correctness as possible while it is a Reissner-like. This uniquely determines the plate theory. Numerical results from such an optimum Reissner-like theory are presented. These results include comparisons of plate displacement as well as of three-dimensional field variables and are the best of all extant Reissner-like theories. Indeed, they even surpass results from theories that carry many more generalized displacement variables. Although the derivation presented herein is inspired by, and completely equivalent to, the well-known variational-asymptotic method, the new procedure looks different. In fact, one does not have to be familiar with the variational-asymptotic method in order to follow the present derivation.

scholarly journals A New Hyperbolic Shear Deformation Theory for Bending Analysis of Functionally Graded Plates

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Tahar Hassaine Daouadji ◽  
Abdelaziz Hadj Henni ◽  
Abdelouahed Tounsi ◽  
Adda Bedia El Abbes
Keyword(s):  
Shear Deformation ◽  
Volume Fraction ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Flexural Behavior ◽  
Deformation Model ◽  
Functionally Graded Plates ◽  
Volume Fractions ◽  
Aspect Ratios ◽  
Fg Plates

Theoretical formulation, Navier’s solutions of rectangular plates based on a new higher order shear deformation model are presented for the static response of functionally graded plates. This theory enforces traction-free boundary conditions at plate surfaces. Shear correction factors are not required because a correct representation of transverse shearing strain is given. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Numerical illustrations concern flexural behavior of FG plates with metal-ceramic composition. Parametric studies are performed for varying ceramic volume fraction, volume fractions profiles, aspect ratios, and length to thickness ratios. Results are verified with available results in the literature. It can be concluded that the proposed theory is accurate and simple in solving the static bending behavior of functionally graded plates.

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