scholarly journals Evaluation of Stress Distribution of Isotropic, Composite, and FG Beams with Different Geometries in Nonlinear Regime via Carrera-Unified Formulation and Lagrange Polynomial Expansions

2021 ◽  
Vol 11 (22) ◽  
pp. 10627
Author(s):  
Erasmo Carrera ◽  
Munise Didem Demirbas ◽  
Riccardo Augello
Keyword(s):  
Cross Sections ◽  
Composite Structures ◽  
Axial Loading ◽  
Mechanical Effect ◽  
Functionally Graded ◽  
Nonlinear Behaviour ◽  
Lagrange Polynomial ◽  
Isotropic Composite ◽  
Carrera Unified Formulation ◽  
Polynomial Expansions

In this study, the geometrically nonlinear behaviour caused by large displacements and rotations in the cross sections of thin-walled composite beams subjected to axial loading is investigated. Newton–Raphson scheme and an arc length method are used in the solution of nonlinear equations by finite element method to determine the mechanical effect. The Carrera-Unified formulation (CUF) is used to solve nonlinear, low or high order kinematic refined structure theories for finite beam elements. In the study, displacement area and stress distributions of composite structures with different angles and functionally graded (FG) structures are presented for Lagrange polynomial expansions. The results show the accuracy and computational efficiency of the method used and give confidence for new research.

Glass-Alumina Functionally Graded Materials Produced by Plasma Spraying

2007 ◽  
Vol 333 ◽  
pp. 227-230
Author(s):  
Valeria Cannillo ◽  
Luca Lusvarghi ◽  
Tiziano Manfredini ◽  
M. Montorsi ◽  
Cristina Siligardi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Plasma Spraying ◽  
Functionally Graded Materials ◽  
Cross Sections ◽  
Functionally Graded ◽  
Depth Sensing ◽  
Graded Materials ◽  
Set Up ◽  
Scanning Electron

The present work was focused on glass-alumina functionally graded materials. The samples, produced by plasma spraying, were built as multi-layered systems by depositing several layers of slightly different composition, since their alumina and glass content was progressively changed. After fabricating the graded materials, several, proper characterization techniques were set up to investigate the gradient in composition, microstructure and related performances. A particular attention was paid to the observation of the graded cross sections by scanning electron microscopy, which allowed to visualize directly the graded microstructural changes. The scanning electron microscopy (SEM) inspection was integrated with accurate mechanical measurements, such as systematic depth-sensing Vickers microindentation tests performed on the graded cross sections.

scholarly journals ANALYSIS OF THE TIME‐DEPENDENT BEHAVIOUR OF COMPOSITE CROSS‐SECTIONS BY LAPLACE‐TRANSFORM

2005 ◽  
Vol 11 (3) ◽  
pp. 203-209
Author(s):  
Erich Raue ◽  
Thorsten Heidolf
Keyword(s):  
Laplace Transform ◽  
Cross Sections ◽  
Composite Structures ◽  
Time Dependent ◽  
Time Interval ◽  
Final State ◽  
Long Time ◽  
Time Dependent Behaviour ◽  
Linear Differential ◽  
Dependent Behaviour

Composite structures consisting of precast and cast in‐situ concrete elements are increasingly common. These combinations demand a mechanical model which takes into account the time‐dependent behaviour and analysis of the different ages of the connected concrete components. The effect of creep and shrinkage of the different concrete components can be of relevance for the state of serviceability, as well as for the final state. The long‐time behaviour of concrete can be described by the rate‐of‐creep method, combined with a discretisation of time. The internal forces are described for each time interval using a system of linear differential equations, which can be solved by Laplace‐transform.

scholarly journals Analysis of steel reinforced functionally graded concrete beam cross sections

2018 ◽  
Vol 195 ◽  
pp. 02031 ◽  
Author(s):  
Shota Kiryu ◽  
Ay Lie Han ◽  
Ilham Nurhuda ◽  
Buntara S. Gan
Keyword(s):  
Cross Sections ◽  
Iterative Procedure ◽  
Concrete Beam ◽  
Analytical Procedure ◽  
Functionally Graded ◽  
Neutral Axis ◽  
Mechanical Behaviors ◽  
Beam Structure ◽  
Axis Position ◽  
Concrete Materials

Owing to continuously changing strength moduli properties, functionally graded concrete (FGC) has remarkable advantages over the traditional homogeneous concrete materials regarding cement optimization. Some researchers have studied mechanical behaviors and production methodologies. Problems arise as to how to incorporate the effects of the non-homogeneity of concrete strengths in the analysis for design. For a steel Reinforced Functionally Graded Concrete (RFGC) beam structure, the associated boundary conditions at both ends have to be at the neutral axis position after the occurrence of the presumed cracks. Because the neutral axis is no longer at the mid-plane of the beam crosssection, an iterative procedure has to be implemented. The procedure is somewhat complicated since the strength of the beam cross section has to be integrated due to the non-homogeneity in concrete strengths. This paper proposes an analytical procedure that is very straightforward and simple in concept, but accurate in designing the steel reinforced functionally graded concrete beam cross-sections.

scholarly journals Stereological Estimation of Orientation Distribution of Generalized Cylinders from a Unique 2D Slice

2013 ◽  
Vol 19 (6) ◽  
pp. 1678-1687 ◽  
Author(s):  
Jean-Pierre Da Costa ◽  
Stefan Oprean ◽  
Pierre Baylou ◽  
Christian Germain
Keyword(s):  
Cross Sections ◽  
Composite Structures ◽  
Large Scale ◽  
Fibrous Composite ◽  
Three Dimensional ◽  
Synthetic Data ◽  
Inequality Constraints ◽  
Orientation Distribution ◽  
Industrial Applications ◽  
Cost Constraints

AbstractThough three-dimensional (3D) imaging gives deep insight into the inner structure of complex materials, the stereological analysis of 2D snapshots of material sections is still necessary for large-scale industrial applications for reasons related to time and cost constraints. In this paper, we propose an original framework to estimate the orientation distribution of generalized cylindrical structures from a single 2D section. Contrary to existing approaches, knowledge of the cylinder cross-section shape is not necessary. The only requirement is to know the area distribution of the cross-sections. The approach relies on minimization of a least squares criterion under linear equality and inequality constraints that can be solved with standard optimization solvers. It is evaluated on synthetic data, including simulated images, and is applied to experimental microscopy images of fibrous composite structures. The results show the relevance and capabilities of the approach though some limitations have been identified regarding sensitivity to deviations from the assumed model.

Evaluations of failure initiation criteria for predicting damages of composite structures under crushing loading

2018 ◽  
Vol 37 (21) ◽  
pp. 1279-1303 ◽  
Author(s):  
Hongyong Jiang ◽  
Yiru Ren ◽  
Zhihui Liu ◽  
Songjun Zhang ◽  
Xiaoqing Wang
Keyword(s):  
Composite Structures ◽  
Maximum Stress ◽  
Failure Modes ◽  
Damage Model ◽  
Axial Loading ◽  
Failure Criteria ◽  
Quantitative Relation ◽  
Stress Criterion ◽  
Failure Initiation ◽  
Numerical Predictions

The crushing behaviors of thin-walled composite structures subjected to quasi-static axial loading are comparatively evaluated using four different failure initiation criteria. Both available crushing tests of composite corrugated plate and square tube are used to validate the stiffness degradation-based damage model with the Maximum-stress criterion. Comparatively, Hashin, Maximum-stress, Stress-based Linde, and Modified criteria are respectively implemented in the damage model to predict crush behaviors of corrugated plate and square tube. To develop failure criteria, effects of shear coefficients and exponents in the Modified and Maximum-stress criteria on damage mechanisms of corrugated plate are discussed. Results show that numerical predictions successfully capture both of experimental failure modes and load–displacement responses. The Modified criterion and particularly Maximum-stress criterion are found to be more appropriate for present crush models of corrugated plate and square tube. When increasing the failure index, the crushing load is decreased, which also causes premature material failure. The shear coefficient and exponents have dramatic influence on the crushing load. Overall, an insight into the quantitative relation of failure initiation is obtained.

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