scholarly journals Inverse Identification of Elastic Properties of Constituents of Discontinuously Reinforced Composites

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2332 ◽  
Author(s):  
Witold Ogierman
Keyword(s):  
Composite Materials ◽  
Elastic Properties ◽  
Micromechanical Model ◽  
Reinforced Composites ◽  
Inverse Identification ◽  
Identification Procedure ◽  
Uncertain Input ◽  
Uncertain Input Data ◽  
Selection Of

This paper is devoted to determination of elastic properties of composite constituents by using an inverse identification procedure. The aim of the developed identification procedure is to compute the elastic constants of individual material phases on the basis of known properties of composite materials. The inverse problem of identification has been solved by combining an evolutionary algorithm with a micromechanical model. The paper also focuses on selection of a suitable micromechanical model for optimization which should ensure a compromise between accuracy and complexity. Two different cases have been studied: composite reinforced with short cylindrical fibers and composite reinforced with cubic particles. Moreover, Monte Carlo simulations have been carried out to expose a difference in outcome of identification which may occur when uncertain input data is considered. Obtained results show that identification is successful only when properties of composite materials with at least two different volume fractions of the reinforcement are known.

scholarly journals Void and Moisture Content of Fiber Reinforced Composites

2021 ◽  
Vol 87 (3) ◽  
pp. 78-93
Author(s):  
Nurul Zuhairah Mahmud Zuhudi ◽  
Afiq Faizul Zulkifli ◽  
Muzafar Zulkifli ◽  
Ahmad Naim Ahmad Yahaya ◽  
Nurhayati Mohd Nur ◽  
...  
Keyword(s):  
Moisture Content ◽  
Short Review ◽  
Fiber Reinforced Composites ◽  
Moisture Determination ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Mechanical Performances ◽  
Future Work ◽  
Selection Of

In this paper, a short review on the void and moisture content studies of fiber reinforced composites for both, synthetic and natural based fibers are presented. The review summarized the research papers in which include experimental and theoretical works that related to the void and moisture content studies. In addition to that, this review paper highlighting a few research studies conducted in literature on the effects of the void and moisture on the mechanical performances of the composite. Few common measurement methods used for the void and moisture determination are discussed here. The aims of this short review, mainly to capture the trend ranging from the recent five years back and summarize the various studies and also to compare and conclude the most common method for the determination of the void and moisture content. This paper is mainly providing a baseline in the selection of the methods for the future work of the author’s work with regard to the reduction of the presence of voids and moisture occur during the impregnation process of fiber reinforced composites, especially when using natural-based fiber.

Optimization of the installation sequence for the temporary fasteners in the aircraft industry

2021 ◽  
pp. 1-25
Author(s):  
Tatiana Pogarskaia ◽  
Sergey Lupuleac ◽  
Julia Shinder ◽  
Philipp Westphal
Keyword(s):  
Combinatorial Problem ◽  
Hole Drilling ◽  
Assembly Process ◽  
Process Verification ◽  
Final Assembly ◽  
Uncertain Input ◽  
Uncertain Input Data ◽  
Aircraft Production

Abstract Riveting and bolting are common assembly methods in aircraft production. The fasteners are installed immediately after hole drilling and fix the relative tangential displacements of the parts, that took place. A proper fastener sequence installation is very important because a wrong one can lead to a “bubble-effect”, when gap between parts after fastening becomes larger in some areas rather than being reduced. This circumstance affects the quality of the final assembly. For that reason, the efficient methods for determination of fastening sequence taking into account the specifics of the assembly process are needed. The problem is complicated by several aspects. First of all, it is a combinatorial problem with uncertain input data. Secondly, the assembly quality evaluation demands the time-consuming computations of the stress-strain state of the fastened parts caused by sequential installation of fasteners. Most commonly used strategies (heuristic methods, approximation algorithms) require a large number of computational iterations what dramatically complicates the problem. The paper presents the efficient methods of fastener sequence optimization based on greedy strategy and the specifics of the assembly process. Verification of the results by comparison to commonly used installation strategies shows its quality excellence.

Micromechanics-based analyses of short fiber-reinforced composites with functionally graded interphases

2019 ◽  
Vol 54 (8) ◽  
pp. 1031-1048 ◽  
Author(s):  
Yang Yang ◽  
Qi He ◽  
Hong-Liang Dai ◽  
Jian Pang ◽  
Liang Yang ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Elastic Properties ◽  
Effective Properties ◽  
Micromechanical Model ◽  
Short Fiber ◽  
Functionally Graded ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
The Matrix

A micromechanical model for short fiber-reinforced composites (SFRCs) with functionally graded interphases and a systematic prediction scheme to determine the effective properties are presented. The matrix and the fibers are regarded to be linear elastic, isotropic, and homogeneous. Fibers are assumed to be ellipsoids coated perfectly by functionally graded interphases, which is supposed to be formed chemically or physically by the constituents near the interface. First, to analyze the grading interphase effect, layer-wise concept is followed to divide the functionally graded interphases into multi-homogeneous sub-layers. Next, to take the effect of functionally graded interphases into account, a combination of multi-inclusion method and Mori–Tanaka method is applied to predict effective elastic properties of this unidirectional SFRCs with respect to the content and aspect ratio of the inclusions. By employing coordinate transformation, spatially elastic moduli are obtained. Finally, Voigt homogenization scheme is used to obtain the overall, averaged, symmetrical elastic properties of the SFRCs. Numerical examples and analyses demonstrate the applicability of the proposed method and indicate the influences of graded interphase, orientation, and aspect ratio of inclusions as well as properties and contents of the constituents on the overall properties of SFRCs.

Determination of Flexible Interlayer Thickness for Fiber Reinforced Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
King H. Lo ◽  
Robert W. Schmitz ◽  
William G. Gottenberg
Keyword(s):  
Fiber Composites ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Stress Distributions ◽  
Interlayer Thickness ◽  
Fiber Reinforced ◽  
The Matrix ◽  
Composite Cylinders ◽  
Selection Of

AbstractThe influence of flexible interlayers/interphases on the performance of unidirectional fiber reinforced composites is studied. Micromechanical analysis based on the embedded composite cylinders model is used to study the stiffness as well as the internal stress distributions within the matrix phase of composites. Based on the results of the analysis, a criterion is proposed for the selection of optimal interlayer thickness for fiber composites. The proposed criterion gives results which seem to correlate well with the experimental data published in the literature.

scholarly journals A Test Method for Experimental Determination of Shear Moduli of Fibre Reinforced Composite Materials

1994 ◽  
Vol 3 (1) ◽  
pp. 096369359400300
Author(s):  
B. Laleh ◽  
P. Myler
Keyword(s):  
Composite Materials ◽  
Carbon Fibre ◽  
Transverse Shear ◽  
Test Method ◽  
Reinforced Composites ◽  
Simple Test ◽  
Shear Moduli ◽  
Reinforced Composite ◽  
Fibre Reinforced Composites

This paper describes a simple test method for determining the in-plane and transverse shear moduli of unidirectional carbon fibre reinforced composites. The method employs photoelastic coating techniques in conjunction with four point offset bend loading conditions.

Determination of elastic properties of triax composite materials

2003 ◽  
Vol 63 (3-4) ◽  
pp. 437-443 ◽  
Author(s):  
S.V. Hoa ◽  
S.Z. Sheng ◽  
P. Ouellette
Keyword(s):  
Composite Materials ◽  
Elastic Properties

Inverse identification of elastic properties of composite materials using hybrid GA-ACO-PSO algorithm

2017 ◽  
Vol 26 (10) ◽  
pp. 1432-1463 ◽  
Author(s):  
Jun Hui Tam ◽  
Zhi Chao Ong ◽  
Zubaidah Ismail ◽  
Bee Chin Ang ◽  
Shin Yee Khoo ◽  
...  
Keyword(s):  
Composite Materials ◽  
Elastic Properties ◽  
Pso Algorithm ◽  
Inverse Identification

scholarly journals Cable-stayed coverings for large-span public buildings

2021 ◽  
Vol 280 ◽  
pp. 07008
Author(s):  
Radomir Timchenko ◽  
Stanislav Popov ◽  
Dmitry Krishko ◽  
Goodary Rajeshwar ◽  
Aleksej Aniskin
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Optimization Problem ◽  
Optimal Result ◽  
Large Span ◽  
Roof Structure ◽  
Standard Design ◽  
Design Characteristics ◽  
Selection Of

Structural schemes of coverings using lightweight roof structure from modern composite materials are investigated in this paper. A comparison of two options for cable-stayed covering of a circus auditorium, one with an orthogonal mesh of cables (according to a standard design) and another one, with a mesh of cables formed by two groups of stabilizing cables are considered. The possibilities of reinforcement with composite material are analyzed. Calculation and preliminary selection of cable-stayed sections are also carried out and presented. The variations of the conditional volume with the relative sag arrows, for varying values of the coefficient qk have been investigated and shown on graphs. An optimization problem was solved and the optimal result with detailed calculations are proposed and presented in this research which enable the design of the cable-stayed coating with determination of its design characteristics. As a result, the optimum and most economical sections of the cable-stayed covering were obtained. The calculations also show the inexpediency of using a heavy roof structure for saddle cable-stayed coverings due to the exclusion of stabilizing cables from the operation with a large roof weight.

Sign in / Sign up

Export Citation Format

Share Document