scholarly journals Experience nature as a basis for building strong composite structures

Vestnik MGSU ◽  
2021 ◽  
pp. 1191-1216
Author(s):  
Alexander N. Polilov ◽  
Nikolay A. Tatus’
Keyword(s):  
Composite Structures ◽  
Open Space ◽  
Fiber Composite ◽  
Crack Arrest ◽  
Strength Properties ◽  
Fibrous Composites ◽  
Reinforcement Structure ◽  
Correct Determination ◽  
Design Calculations ◽  
Effective Use

Introduction. The article is devoted an analytical overview of the methods of applying the Nature solutions for designing structures made of plastics reinforced with fibers, in particular, using rational curved fiber trajectories. The first section provides an overview of different structural models and some approaches to the micromechanics of composites. Materials and methods. Sections 2-7 discuss: analysis of rational elastic-strength properties of wood and composites for crack arrest by weak interface; methods for constructing curved paths of fibers of “flowing holes”; analyzes the applied and promising technologies for manufacturing attachment points, in which holes are formed using curvilinear fiber paths; “nature-inspired” principles of optimal design of pipe composite structures similar in structure to ladder of bamboo stalk; examples of the effective use of fibrous composites in elastic elements such as leaf springs; developing additive technologies for 3D printing of fiber composite parts with fiber laying along calculated trajectories. Results. Each section of the article presents conclusions related to the peculiarities of composites structures calculation and design: calculations show that in order to increase the crack resistance of fibrous composites, it is necessary to significantly increase the shear characteristics of the binder and strive for rational properties created by Nature in wood; as a result of the calculation, it turns out that the maximum stress per fiber at the optimal reinforcement structure becomes about 3–4 times less than with a uniform rectilinear laying; rational reinforcement leads to a significant reduction in local stresses per fiber, elimination of splits and damages of fibers and an increase in the carrying capacity of the assembly; it has been shown that the bamboo rings are arranged to prevent the barrel from splitting from bending compressive stresses and tangential stresses when the barrel is twisted by wind load; analyzed the relationship of equal-strength profiling with Leonardo’s rule for tree crown branching. The works on creation of bio-similar shape and structure of curvilinear reinforcement of specimens for correct determination of unidirectional composites strength at tension along fibres were discussed; analyzed the role of composite technologies in modern mechanical engineering, in particular, in the creation of composite structures in open space. Conclusions. The article is devoted to the analysis of the tasks of fibrous composites macromechanics, therefore, in the opinion of the authors, the three most promising and related areas in macromechanics of composites that require further research are biomechanics of strength, computer modeling of optimal structures and technological mechanics of composites.

Micro-, Macromechanical and Aeroelastic Investigation of Glass-Fiber Based, Lightweight Turbomachinery Components

2020 ◽  
Author(s):  
Senad Iseni ◽  
Mahesh Ramaswamy Guru Prasad ◽  
Alexander Hartmaier ◽  
Klaudiusz Holeczek ◽  
Niels Modeler ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Glass Fiber ◽  
Elastic Properties ◽  
High Speed ◽  
Fiber Composite ◽  
Strength Properties ◽  
Reinforcement Structure ◽  
Distributed Propulsion ◽  
Anisotropic Elastic ◽  
Aero Engines

Abstract A major technical challenge for modern aero engines is the development of designs which reduce noise and emission whilst increasing aerodynamic efficiency and ensuring aeroelastic stability of low-temperature engine components such as fans and low-pressure compressors. Composites are used in aviation due to their excellent stiffness and strength properties, which also enable additional flexibility in the design process. The weight reduction of the turbomachine components, due to composite materials and lighter engines, is especially relevant for the design and developments of hybrid-electric or distributed propulsion systems [1]. To accomplish this, a representative volume element (RVE) of a glass-fiber reinforced polymer is created, describing the geometrical arrangement of the textile reinforcement structure within the polymer matrix. For both phases, realistic linear elastic properties are assumed. This RVE will be investigated with the finite element method under various loading conditions to assess its anisotropic elastic properties and also its damping behaviour for elastic waves. To study the influence of delamination on the mechanical properties, small defects will be introduced into the model at the interface between reinforcement and matrix. Based on this micromechanical approach, a constitutive model for the composite will be formulated that describes the anisotropic properties as well as the damping behaviour. This constitutive model is then used to describe the material response in a macro-mechanical model, which serves as the basis for an aeroelastic analysis of a 1/3-scaled high-speed fan using a conventional (Ti-6Al-4V) and fiber composite material.

Modeling of fiber composite structures for the calculation of the structural intensity

2021 ◽  
Vol 262 ◽  
pp. 113631
Author(s):  
Pasquale Junior Capasso ◽  
Giuseppe Petrone ◽  
Nikolai Kleinfeller ◽  
Sergio De Rosa ◽  
Christian Adams
Keyword(s):  
Composite Structures ◽  
Fiber Composite ◽  
Structural Intensity

The effect of nanoparticle additive on surface milling in glass fiber reinforced composite structures

2021 ◽  
pp. 096739112110141
Author(s):  
Ferhat Ceritbinmez ◽  
Ahmet Yapici ◽  
Erdoğan Kanca
Keyword(s):  
Composite Materials ◽  
Glass Fiber ◽  
Composite Structures ◽  
Fiber Composite ◽  
Cutting Speed ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Composite Layers

In this study, the effect of adding nanosize additive to glass fiber reinforced composite plates on mechanical properties and surface milling was investigated. In the light of the investigations, with the addition of MWCNTs additive in the composite production, the strength of the material has been changed and the more durable composite materials have been obtained. Slots were opened with different cutting speed and feed rate parameters to the composite layers. Surface roughness of the composite layers and slot size were examined and also abrasions of cutting tools used in cutting process were determined. It was observed that the addition of nanoparticles to the laminated glass fiber composite materials played an effective role in the strength of the material and caused cutting tool wear.

Fiber Composite Strength Modeling With Extension to Life Prediction

2005 ◽  
Vol 128 (1) ◽  
pp. 41-49
Author(s):  
Edward M. Wu ◽  
John L. Kardos
Keyword(s):  
Composite Structures ◽  
Life Prediction ◽  
Failure Modes ◽  
Fiber Composite ◽  
Probability Model ◽  
Load Sharing ◽  
Local Load ◽  
Statistical Parameters ◽  
Composite Strength ◽  
Fiber Manufacturing

This paper focuses on the probability modeling of fiber composite strength, wherein the failure modes are dominated by fiber tensile failures. The probability model is the tri-modal local load-sharing model, which is the Phoenix-Harlow local load-sharing model with the filament failure model extended from one mode to three modes. This model results in increased efficiency in the determination of fiber statistical parameters and in lower cost when applied to (i) quality control in materials (fiber) manufacturing, (ii) materials (fiber) selection and comparison, (iii) accounting for the effect of size scaling in design, and (iv) qualification and certification of critical composite structures that are too large and expensive to test statistically. In addition, possible extensions to proof testing and time-dependent life prediction are discussed and preliminary data are presented.

scholarly journals Bearing capacity of RC beams reinforced with high strength rebars and steel plate

2018 ◽  
Vol 230 ◽  
pp. 02003 ◽  
Author(s):  
Taras Bobalo ◽  
Yaroslav Blikharskyy ◽  
Rostyslav Vashkevich ◽  
Myhailo Volynets
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Steel Plate ◽  
Concrete Structures ◽  
High Strength ◽  
Strength Properties ◽  
Rc Beams ◽  
Reinforcing Bars ◽  
External Reinforcement ◽  
Effective Use

Nowadays, reducing the material content of not only buildings and structures in general, but also individual constructions is a topical task that can be realized through the use of high-strength concrete and reinforcement, as well as with the use of external reinforcement. The concentrated location of sheet reinforcement on the external the most tense facets of steel and concrete structures increases the operating height of the cross-section, makes it possible to more effectively use the strength properties of steel in comparison with conventional reinforced concrete, and with the same bearing capacity to economize on expenses. Composite and monolithic reinforced concrete structures with external reinforcement are used in various construction sectors around the world. This contributed to the expansion of the use of reinforced concrete for special buildings of power-engineering and hydrotechnical construction. The technical nd econom efficiency, as well as the possibility of using external rebar as formwork for monolithic concrete construction, have been proved. Therefore, there is a need for the study of structures with combined reinforcement, in which high rigidity of steel and concrete structures is combined with an effective use of high-strength reinforcing bars (rebar) without prior tension

scholarly journals Impact Damage Resistance and Post-Impact Tolerance of Optimum Banana-Pseudo-Stem-Fiber-Reinforced Epoxy Sandwich Structures

2020 ◽  
Vol 10 (2) ◽  
pp. 684 ◽  
Author(s):  
Mohamad Zaki Hassan ◽  
S. M. Sapuan ◽  
Zainudin A. Rasid ◽  
Ariff Farhan Mohd Nor ◽  
Rozzeta Dolah ◽  
...  
Keyword(s):  
Composite Structures ◽  
Sandwich Structures ◽  
Impact Damage ◽  
Fiber Composite ◽  
Peak Load ◽  
Weight Ratio ◽  
Synthetic Fiber ◽  
Damage Area ◽  
Banana Fibers ◽  
The Impact

Banana fiber has a high potential for use in fiber composite structures due to its promise as a polymer reinforcement. However, it has poor bonding characteristics with the matrixes due to hydrophobic–hydrophilic incompatibility, inconsistency in blending weight ratio, and fiber length instability. In this study, the optimal conditions for a banana/epoxy composite as determined previously were used to fabricate a sandwich structure where carbon/Kevlar twill plies acted as the skins. The structure was evaluated based on two experimental tests: low-velocity impact and compression after impact (CAI) tests. Here, the synthetic fiber including Kevlar, carbon, and glass sandwich structures were also tested for comparison purposes. In general, the results showed a low peak load and larger damage area in the optimal banana/epoxy structures. The impact damage area, as characterized by the dye penetration, increased with increasing impact energy. The optimal banana composite and synthetic fiber systems were proven to offer a similar residual strength and normalized strength when higher impact energies were applied. Delamination and fracture behavior were dominant in the optimal banana structures subjected to CAI testing. Finally, optimization of the compounding parameters of the optimal banana fibers improved the impact and CAI properties of the structure, making them comparable to those of synthetic sandwich composites.

Sign in / Sign up

Export Citation Format

Share Document