Composites have been found to be the most promising and discerning material available in this century. Presently, composites reinforced with fibers of synthetic or natural materials are gaining more importance as demands for lightweight materials with high strength for specific applications are growing in the market. Fiber-reinforced polymer composite offers not only high strength to weight ratio, but also reveals exceptional properties such as high durability; stiffness; damping property; flexural strength; and resistance to corrosion, wear, impact, and fire. These wide ranges of diverse features have led composite materials to find applications in mechanical, construction, aerospace, automobile, biomedical, marine, and many other manufacturing industries. Performance of composite materials predominantly depends on their constituent elements and manufacturing techniques, therefore, functional properties of various fibers available worldwide, their classifications, and the manufacturing techniques used to fabricate the composite materials need to be studied in order to figure out the optimized characteristic of the material for the desired application. An overview of a diverse range of fibers, their properties, functionality, classification, and various fiber composite manufacturing techniques is presented to discover the optimized fiber-reinforced composite material for significant applications. Their exceptional performance in the numerous fields of applications have made fiber-reinforced composite materials a promising alternative over solitary metals or alloys.

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Fiber-Reinforced Polymer Composites: Manufacturing, Properties, and Applications.

Mechanical analysis of functionally graded carbon nanotube reinforced composites: A review

The review outlines modern trends in theoretical developments, novel designs and modern applications of sandwich structures. The most recent work published at the time of writing of this review is considered, older sources are listed only on as-needed basis. The review begins with the discussion on the analytical models and methods of analysis of sandwich structures as well as representative problems utilizing or comparing these models. Novel designs of sandwich structures is further elucidated concentrating on miscellaneous cores, introduction of nanotubes and smart materials in the elements of a sandwich structure as well as using functionally graded designs. Examples of problems experienced by developers and designers of sandwich structures, including typical damage, response under miscellaneous loads, environmental effects and fire are considered. Sample applications of sandwich structures included in the review concentrate on aerospace, civil and marine engineering, electronics and biomedical areas. Finally, the authors suggest a list of areas where they envision a pressing need in further research.

Review of current trends in research and applications of sandwich structures

http://milad-engc.persiangig.com/Recent.pdf

Recent research advances on the dynamic analysis of composite shells: 2000-2009

Emerged in the middle of 20th century, composite materials are now one of the hotspot research topics in the modern technology. Their promising characteristics make them suitable for enormous applications in industrial field such as aerospace, automotive, construction, sports, bio-medical and many others. These materials reveal remarkable structural and mechanical properties such as high strength to weight ratio, resistance to chemicals, fire, corrosion and wear; being economical to manufacture. Herein, an overview of composite materials, their characterization, classification and main advantages linked to physical and mechanical properties based on the recent studies are presented. There, were presented the conventional manufacturing techniques of composite and their applications. It was highlighted the tremendous need to discovery new generation of composites that should incorporate the synthetic or natural materials by implementing new efficient manufacturing processes. In the combination of matrix and reinforcement materials, the use of natural materials as constituent are compulsory in order to obtain a complete material degradable as environmentally friendly.

Recent progress of reinforcement materials: a comprehensive overview of composite materials

Modeling of the Martensite Transformation and Reorientation in SMA under Thermomechanical Loading. Design of Finite Element Adaptative Micro‐Components

The use of the weight functions in fracture mechanics appears in the literature in a very increasing way in particular in the computation of the stress intensity factor (SIF). The difficulties of calculation of this significant parameter, which come from the analytical singularities present in its formulation, encourage the use of the methods using weight functions for both their simplicity and their effectiveness with respect to the other approximate methods. This work consists on the hybridization of two weight functions developed by Oore & Burns [1] and Krasowsky & al.[2] in order to model the elliptical cracks for the computation of the stress intensity factor (SIF) in mode I. The idea of hybridization consists in dividing the ellipse into two zones, then to use each one of them in the area where it is more efficient. The proportion between the two zones is determined by optimization of the relationship between the small one and the large axis of the ellipse. Compared with the exact solution, the maximum error of the results obtained is of 2.4%, whereas, for those of Krasowsky & al.[2] and Oore & Burns[1], the maximum error is 6.3% and 17.4%, respectively, and this in the case of an elliptical crack uniformly charged in an infinite body. Our approach is tested on another practical example of an internal semi-elliptical crack in tubes. In the absence of the exact solutions, the results found by our calculations are in strong correlation with those of other authors using various techniques (FEM for [3] & WFM for [2]). The idea of hybridization thus really demonstrated its effectiveness like its flexibility in the computation of SIF for a variety of problems in fracture mechanics. 1INTRODUCTION The development of the weight functions in fracture mechanics started with the work of Bueckner [4] in 1970, based on the formulation by the Green’s function, for a semi-infinite crack, in an infinite medium. The investigation in the weight functions on the one hand and the evaluation of the energy balance formula of Rice [5] on the other hand, allowed the extension of the use of the weight functions by several authors such as Oore & Burns [1] and Bortmann & Al. [6]. In 1986, Gao & Rice [7] introduced the study of the stability of the fictitiously disturbed rectilinear form from which results the values of SIF along the crack front. Other investigations related especially to the fissure shape (ellipse, half of ellipse, quarter of ellipse, rectangle. . .), to the mode of rupture (mode I, II, III or mixed), and to the large domain of application (elastoplastic, elastodynamic, thermoelastic. . .), consequently succeeded. Among those works, one can chronologically mention, Fett & al.[8] (1989), Vainshtok & al.[9] (1990), Dominguez & al.[10] (1992), Rooke & al.[11] (1994), Orynyak & al.[12] (1995), Zheng & al.[13] (1997), Kiciak & al.[14] (1998), Pommier & al.[15] (1999), Krasowsky & al.[2] (1999), Hachi & al.[16] (2003) and Christopher & al.[17] (2004). The principle of the weight function technique consists in employing one or more known solutions (known as of reference) of a particular case in order to find the solution for the general case. The reference solution generally comes from the analytical results (exact). But in some cases, the absence of such results obliges the authors, such as [12], [13], [14], [15] and [17], to use approximate solutions which could be the existing weight functions. The solution of the SIF in mode I using the weight function technique is given by the general form [12]:

4210 - a hybrid weight function approach for the computation of stress intensity factor in elliptical and semi-elliptical cracks

Yet and according to our knowledge, the extended finite element method X-FEM has not been used in the dynamic response of cracked plates subjected to impact loading, subject of this study. From prior knowledge of the impact properties (contact force and central deflection) of a virgin plate, one can quantitatively through the present study predicts the eventual presence of discontinuities in plates by comparison of impact properties of cracked plate to the virgin ones. In the numerical implementation, conventional finite element without any discontinuity is first carried out, then enriched functions are added to nodal displacement field for element nodes containing cracks. Therefore no remeshing of the domain is required, leading to a great gain in time computing. The mathematical model includes both transverse shear deformation and rotatory inertia effects. Based on the above, a self contained computer code named “REDYPLAF”, written in FORTRAN is hence developed. The effects of Crack length and crack position on contact force and on plate deflection are analyzed. The obtained results show that the contact force is divided into three zones. The same fact is also observed for the maximum plate deflection. Another observed fact is related to crack dissymmetry which has a direct effect on the maximum plate deflection.

Dynamic Response of Cracked Plate Subjected to Impact Loading Using the Extended Finite Element Method (X-FEM)

A hybrid weight function technique is presented. It consists of dividing an elliptical crack into two zones, then using the appropriate weight function in the area where it is more efficient. The proportion between zones is determined by optimizing two crack parameters (axis ratio and curvature radius). Stress intensity factors are hence computed by a self developed computer code. Static and fatigue loadings are considered. The results found by the present approach are in good correlation with the analytical and experimental solutions (when available) as well as with those obtained numerically by other researchers.

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Analysis of Elliptical Cracks in Static and in Fatigue by Hybridization of Green's Functions

In a recent paper (G. Muscas et al.),1 the magnetomechanical behavior of cobalt (Co) magnetic nanowire arrays on a polymeric substrate (polyethylene naphthalate (PEN)) under bending was measured by magneto-optical Kerr effect (MOKE) magnetometry in situ. The authors showed that the magnetomechanical effects were very small and assigned this result to a low effective magnetostriction coefficient due to the nanostructuring. In this comment, we show by numerical calculations that it is the ongoing/current stress distribution within the system that generates this effect. Indeed, the nanostructures being very rigid with respect to the compliant substrate, the strains are mainly concentrated in the substrate and less than 3% of the macroscopic stress is transmitted to the nanostructures.

Comment on "Ultralow magnetostrictive flexible ferromagnetic nanowires" by G. Muscas, P. E. Jönsson, I. G. Serrano, Ö. Vallin, and M. V. Kamalakar, Nanoscale, 2021, 13, 6043-6052.

Mohamed Haboussi

Papers

Modeling of the Martensite Transformation and Reorientation in SMA under Thermomechanical Loading. Design of Finite Element Adaptative Micro‐Components

4210 - a hybrid weight function approach for the computation of stress intensity factor in elliptical and semi-elliptical cracks

Dynamic Response of Cracked Plate Subjected to Impact Loading Using the Extended Finite Element Method (X-FEM)

Analysis of Elliptical Cracks in Static and in Fatigue by Hybridization of Green's Functions

Comment on "Ultralow magnetostrictive flexible ferromagnetic nanowires" by G. Muscas, P. E. Jönsson, I. G. Serrano, Ö. Vallin, and M. V. Kamalakar, Nanoscale, 2021, 13, 6043-6052.