Application of flax fibre as reinforcement in polymer composites used in the construction and manufacturing industries is a step towards achieving more sustainable construction practices. Flax fabric-reinforced epoxy (FFRE) was used to manufacture forty-two pipes with a variety of internal diameters and flax fabric layers, all with a length-to-internal diameter ratio of 1.5:1. Lateral compression loading

The effect of circular cut-out and low velocity impact damage on shear buckling and post-buckling performances of composite plates was investigated experimentally and numerically. Numerical solution for the buckling problem was obtained using an approximate Ritz method. Experiments were carried out for shear loaded pristine and damaged specimens, with a comparison of out of plane displacements, strain

To study the compressive behavior of rectangular concrete-filled fiber reinforced polymer (FRP)-steel composite tube (CFCT) columns, twenty-nine specimens were tested under compression loading in five series based on the corner radius. The variables are the corner radius of cross-section, the number of layers of FRP and the type of FRP wrapping. The experimental results revealed that the FRP wrapping

Free vibration and damping analysis of porous functionally graded (FG) sandwich plates are presented based on a modified Fourier-Ritz method. The sandwich plate is composed of a viscoelastic core and two porous FG face layers. A complex elasticity modulus is employed to describe the viscoelastic core. Material properties of the porous FG face layer are described continuously across each face thickness

This paper examines the use of natural jute fabric reinforced polymer (JFRP) composite sheets as external strengthening material of reinforced concrete (RC) beams. Pre-damaged RC beam specimens are prepared to represent seismic damage. The shear behaviour of pre-damaged deep RC beams strengthened with JFRP sheets are investigated subjected to non-reversed cyclic three-point bending load test. The JFRP

The GFRP elastic gridshell is a type of spatial structure composed of long continuous hollow GFRP members and has been used in large-span roof structures. The elastic gridshell achieves its shape as the result of elastic deformations during the construction process of lifting or pushing. The shape-forming mechanism of such structures is very complicated due to significant geometric non-linearity. This

A theoretical model was developed for the anti-fatigue design of steel reinforced ECC (Engineered Cementitious Composites) composite system (SRECS) under flexure. The fatigue properties of both ECC and steel reinforcement were comprehensively considered in this model. Static flexure tests on full-scale steel reinforced ECC link slabs were carried out and the previous experimental results of ECC link

A global sensitivity analysis method based on the Gauss-Lobatto integration is proposed and applied to study the attenuation zones of layered periodic foundations including the effect of initial stress. Comparisons with existing results of a mathematical model in previous studies are conducted to validate the proposed method, and the accuracy of the proposed method is found to be superior to the extensively

Functionally graded materials are regarded as a special kind of composites capable of eliminating material interfaces and the delamination problems. Stress discontinuity can be avoided owing to smooth composition of the functionally graded ingredients. In this study, a recently emerged effective non-local continuum theory for solving fracture problems in solids and structures, peridynamics, is employed

The present paper studies the ballistic performance of Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) applying multi-layered concept against the 7.62 mm projectile at 840 m/s. Coarse basalt aggregates are incorporated in the UHPFRC under the premise of reducing the cement powder consumption and taking advantages of their superior ballistic resistance. We found that the designed triple-layered

This paper develops a novel rubberized ultra-lightweight high ductility cement composite (RULCC) with added rubber powder and low content PE fiber (0.7%), and investigates the dynamic compressive response and failure mechanism of the RULCC both experimentally and analytically. The test program examines the dynamic compressive stress-strain relationship of the RULCC through Split Hopkinson Pressure

This paper presents the design and experimental validation of a durable textile reinforced concrete (TRC) panel that can be used to furnish a stay-in-place (SIP) formwork and a protective layer over the outer surface of the reinforced concrete (RC) elements, which require high durability and long service life. The objectives of this study are to increase the flexural capacity and to improve the durability

Epoxy- and vinyl ester-based carbon fibre reinforced sheet moulding compounds (CF-SMCs) were industrially processed and impact tested to characterise their impact energy absorption performance. Particularly, thin-walled CF-SMC components were manufactured via a high volume compression moulding process, and were subjected to both ∼9 m/s and ∼13 m/s dynamic impacts with kinetic energies of ∼3.3 kJ and

Due to the different thermal expansion of the constituent materials, cyclic thermal loading of FRP induces alternating stresses in the material at two scales: at the micro scale (level of fibre–matrix-interaction) and at the macro scale (level of the multidirectional laminate). Especially the micro scale effect is not comprehensively investigated yet. Additionally, computational investigations mostly

This paper investigates damage progression during Open-Hole Tension (OHT) test of carbon fibre-reinforced composites with different Quasi-Isotropic (QI) layups. Digital Image Correlation (DIC) and in-situ edge microscopy are utilized simultaneously to detect damage on the specimen’s surface and in the inner plies, respectively. It is found that damage does not always initiate in the 90° plies, but

This study focuses on the notch effect on the fatigue failure of chopped carbon fiber chip-reinforced sheet molding compound (SMC) composites by using both experimental and numerical methods. The S-N diagrams of notched specimens are first obtained experimentally, which exhibit large scatter and are shown to depend on the spatial distribution of local fiber orientations. After considering the effect

One of the main concerns about FRP-reinforced concrete (RC) structures is the performance of the FRP reinforcement under fire exposure. Previous studies showed that fire resistances above 90 min can be attained if proper anchorage of the rebars is provided and splicing is avoided along spans exposed to fire. However, this topic has not yet been investigated in a comprehensive way. This paper presents

This paper is concerned with the finite element (FE) modeling of mechanical behavior for concrete columns wrapped with fiber reinforced polymer (FRP) materials under uniform compression load. The introduced model is based on modifying damage evolution in concrete and FRP considered as a brittle material. In this work, the Miehe phase-field approach is employed for capturing the damage in the FRP, whereas

Pore defects are unavoidable in 3D braided composites, and can highly reduce the mechanical performance. In this paper, multi-scale analyses are conducted to investigate the effects of pore defects on elastic constants for 3D five-directional braided composites. A modified Chamis model is proposed to calculate elastic properties of yarns with pore defects and validated by the finite element method

Steel fiber reinforced concrete (SFRC) at the structural scale exhibits an enhanced fatigue performance compared to conventional reinforced concrete (RC) with lower stress levels and longer fatigue life. The steel fibers contribute to the crack-bridging strength of the concrete, but how this degrades in the tensile stress zone of an SFRC structural beam during flexural cyclic loading remains unknown

The axial compressive stress-strain behavior of CFRP-confined lightweight aggregate concrete (LWAC) with short carbon fiber and/or polypropylene fiber was investigated. Thirty cylinders with different concrete types (normal weight concrete and LWAC), fiber types (carbon fiber, polypropylene fiber, and mixture of these two fibers), volume faction of fibers (from 0% to 0.4% for each fiber type in single

The aim of the present study is to investigate the effect of introducing an elastomer layer into conventional fiber metal laminates on their perforation resistance. Natural compounded rubber as elastomeric media and glass/epoxy composite were sandwiched in between two layers of aluminum 6061-T6 and then the resulted structure was perforated by a 10 mm diameter hemispherical projectile at different

This study presents a quantitative evaluation of the structural impact of lightning strikes on glass/epoxy and Ni-glass/epoxy composites used in radar-absorbing structures (RAS), as well as the actual design of a 5-slab RAS. Image processing was utilized to evaluate the fiber and resin in the damaged area caused by lightning. The decrease in mechanical properties due to lightning strikes were evaluated

A material-based higher-order shear beam model is proposed for accurate analyses of functionally graded (FG) beams with arbitrary material distribution through thickness. Distinct from the existing higher-order shear beam models, the shear function of the present model is dependent on the material distribution. The specific form of this material-based shear function is described by a piecewise linear

In this paper a strategy for the stress analysis of sandwich plates and shells employing the active face triangular-based prismatic finite element is provided, which combines three-dimensional membrane elements (called active face) with solid elements providing stiffening cells, usually called honeycomb. The connection of solid and active face elements is done by direct nodal correspondence, keeping

The efficacy of the NSM technique using prestressed CFRP laminates for the flexural strengthening of RC slabs was assessed experimentally. The results obtained indicated that the application of NSM CFRP laminates with a certain level of prestress is a suitable strategy to increase the load-carrying capacity of slabs in terms of service limit state (SLS) conditions. The higher is the CFRP prestressed

In this work, a third-order efficient layerwise theory (ELWT) has been developed for laminated composite and sandwich curved beams of deep curvatures. The circumferential displacement is assumed to have global third-order variation in thickness (radial) coordinate with a linear layerwise variation. The number of independent variables is reduced to 3 by imposing the continuity of displacement and transverse

A systematically stepwise analysis (SSA) is presented for the free vibration analysis of rotating functionally graded (FG) turbo-machinery blades with linear and non-linear variable thickness operating in thermal environment. The governing equations are extracted by deployment of principle of the virtual work and Hamilton’s principle in the context of first-order shear deformation plate theory (FSDT)

This study presents closed-form solutions for the critical buckling pressures and characteristic frequencies of underwater composite cylinders. The analytical solutions were derived using the full stiffness definitions from composite laminate theory, making them suitable for symmetric, asymmetric, hybrid, and/or double-shell (sandwich) cylindrical composite structures. These closed-form solutions were

This paper presents an experimental investigation on the flexural behaviour of corroded reinforced concrete (RC) continuous beams strengthened by carbon fabric-reinforced cementitious matrix (C-FRCM). A total of ten specimens with different degrees of corrosion were tested under in-plane bending. The strengthening C-FRCM plates were prefabricated with different layers of carbon fabric meshes for reinforcement

In this work, a cyclic indentation test is employed for the in-situ characterisation of the local mechanical properties of a PR520 epoxy resin matrix in a 3D carbon fiber composite. Since the evolution of indentation response with time is studied, the cyclic loading allows to characterise both the elastic and the time dependent, viscoelastic, mechanical response of the material simultaneously. The

In this study, the sound radiation characteristics of the laminated structures reinforced by honeycomb and composed by viscoelastic material was investigated. Temperature- and frequency-dependent behaviors of the viscoelastic material were considered in this analysis, those parameters affected the dynamics effective properties of the composite structure. After the dynamic equivalent effective stiffness

In this paper we derive a unified formulation for bending of piezoelectric plates with taking into account the assumptions of three plate bending theories, such as the Kirchhoff-Love theory, 1st order and 3rd order shear deformation plate theory. The functional gradation of material coefficients in the transversal as well as in-plane direction complies the rule of mixture. For numerical solution of

Corrugated sandwich structures have been widely used in aerospace and aviation fields due to their excellent performances. In this paper, a new bio-inspired corrugated sandwich structure is designed based on the microstructure of cybister elytra. Moreover, the homogenization method is used to simplify models and the equivalent material parameters are derived by analytical formulation and finite element

This study investigates the influence of basalt fiber reinforced concrete (BFRC) on the bond durability of helically wrapped basalt fiber reinforced polymers (HWBFRP) bars subjected to harsh saline environmental conditions. A total of 63 Pullout specimens were fabricated and tested. Test parameters included conditioning duration (30, 60 and 90 days), conditioning temperature (35 and 60 oC) and the

The electrical and piezoresistive sensing characteristics of polymeric composites incorporating carbon nanotube (CNT) and carbonyl iron powder (CIP) were investigated in this study. A novel manufacturing method was introduced to effectively and uniformly disperse CNT and CIP into polymeric composites. Five different CNT proportions and three different CIP proportions were considered to explore the

Acoustic velocity measurement and the acoustic emission tests of tension-torsion composite failure process for nylon 6 and nylon 66 standard specimens under different loading rates are carried out by using acoustic emission instrument and electronic tension-torsion tester respectively. The acoustic velocity, stress-strain curve and acoustic emission energy curve of each specimen are obtained; According

Extensive experimental investigation was conducted to evaluate the performance of fiber reinforced concrete (FRC) beams that have been externally strengthened with and without preloading in flexure using carbon fiber reinforced polymer sheets. Steel, synthetic and hybrid fibers (mix of steel and synthetic fibers) with a volume fraction of 0.5 % were added to the concrete matrix to prepare 15 beams

This paper focuses on the experimental high temperature fatigue of Carbon/polyimide 8-harness satin woven composite materials. Traction-traction (R=0.1) fatigue tests at 250°C are carried out on Carbon/polyimide [44]6 8-harness satin woven composites under three different environments (air, 2 bar N2, 2 bar O2). Part I is specifically devoted to image based damage characterization by employment of Digital

Up to date, a considerable experimental work has been performed to reveal the impact behavior of polymer foam core sandwich composites. Though, a few attempts have been made to integrate shear thickening fluids (STF) in closed cell rigid polyurethane foams (PU). STF possess a unique rheological property providing a rapid response to the structure against impact loads. The effects of STF on polymer

This study presents a broadband radar-absorbing foam-based sandwich structure (RAS) composed of a foam core, glass fiber–reinforced polymer (GFRP), and electroless nickel–plated glass fabric. The nickel-coated fiber (NCF) for electromagnetic wave absorption is prepared using electroless nickel plating on glass fabric with discussing the detailed electromagnetic wave absorption mechanisms relationship

The strengthening of masonry arch bridges, which account for a significant portion of the railway and road bridges in the world’s infrastructure network, is a pressing need for the operators of such networks, and even more so in the seismic areas. As any interruptions to road and especially rail traffic are particularly costly, and consequently the most suitable solution involves the design of a strengthening

This paper focuses on high temperature fatigue of Carbon/polyimide 8-harness satin woven composite materials. Traction-traction (R=0.1) fatigue tests at 250°C are carried out on Carbon/polyimide [45]6 8-harness satin woven composites under three different environments (air, 2 bar N2, 2 bar O2). Part II is specifically devoted to the study of the environmental effects occurring during high temperature

A generalization of physically-based fixed degrees of freedom 3-D zig-zag theories is developed, which allows for any arbitrary choice of layerwise and representation functions. Thereby users can choose arbitrarily the representation case-by-case. This paper aims to prove that the choice of global and layerwise functions is immaterial whenever coefficients are recalculated exactly (via symbolic calculus)

The stress ratio is commonly known to have an effect on the fatigue delamination growth (FDG) behavior of composite laminates. The crack closure phenomenon during delamination growth may change the value of stress ratio. Whether the stress ratio effect on the FDG behavior is resulted by the crack closure or not is investigated in this study and experimental evidences are presented in order to obtain

Sandwich structures are increasingly applied in many industrial fields of application, due to their lightweight combined with favorable mechanical properties. Despite this, such structures are subject to specific failure modes, such as buckling or vibratory resonance. In both cases, due to the presence of thin and stiff skins, global but also local modes may be of great interest when dimensioning such

In “A sinusoidal beam theory for functionally graded sandwich curved beams” (Composite Structures 226 (2019) 111246), the Navier’s solution was obtained for a so-called simply-supported curved beam at two ends. However, this case is mathematically indeterminate and hence not worked out. Based on the Timoshenko theory, the governing differential equations are formulated for curved beam problems and

Strengthening mechanisms in CNT/metal composites are significant guidelines on composites design. However, the strengthening mechanisms at high temperatures have few been reported. In this work, the evolution of four common strengthening mechanisms in CNT/metal composites, including load transfer strengthening, grain refinement strengthening, enhanced dislocation density strengthening and Orowan strengthening

In this paper, we propose an efficient 3-node shell element with 6 DOFs per node based on Naghdi-Reissner-Mindlin theory. This new composite shell element, further denoted as DKMT18, takes into account shear deformation and coupled bending-membrane energy. DKMT18 element passes membrane, bending, and shear patch tests with no spurious mode. It also performs successfully in standard tests for thick

This paper presents the concept and investigations on a new column form, namely, concrete-filled fiber-reinforced polymer-steel wire reinforced thermoplastics pipe (FRP-SRTP) columns (CFFSCs) which consist of a SRTP tube with an outer FRP confinement system and the concrete filled in the core area. A series of axial compression tests were performed on CFFSCs, and parameters including the number of

Based on the hyperelastic material models, the propagation of nonlinear travelling waves in cylindrical rods has been studied. Here, different types of nonlinear travelling waves in a thermo-hyperelastic neo-Hookean cylindrical shell are determined. By using the variational principle, a complex differential dynamical system describing the axisymmetric motion of the shell is derived. The effect of the

Fiber reinforced plastic composites are promising candidates for building the next generation of automotive and aircraft structures. However, these materials are sensitive to any potential impact, which may cause matrix micro-cracking or internal inter-laminar delamination damages. This study provides insights into the sensitivity of braided Carbon/Kevlar round tubes to external damages and neural

In this work, a numerical analysis of typical composite bonded repairs is performed aiming to establish a comparison between their performance under quasi-static and high-cycle fatigue loading. The studies include progressive damage analysis employing cohesive zone models suitable for quasi-static and high-cycle fatigue under mixed-mode I+II loading. Five repair geometries, e.g., Single-Strap, Double-Strap

The main purpose of this paper is to theoretically explore the effect of selective laser shock processing (LSP) on the forced vibration response of blade based on the functionally graded (FG) Timoshenko’s beam theory. Considering the complexity of direct solution caused by gradient distribution of elastic modulus, pre-stress, and variable cross-section, the actual blade after selective LSP is simplified

A metastructure consisting of numerous unit cells with quasi-zero stiffness property has been designed and researched in this paper. The quasi-zero stiffness property is realized in each unit cell by combining snap-through behavior of a sinusoidal beam and bending dominated support of two semicircular arches. Mechanical behavior of the metastructure is derived theoretically based on the property of

Researchers have recently focused on improving the efficiency of piezoelectric energy harvesters by redesigning their substrate beams. Two approaches have been explored, including changing the shape of the cross-section area, i.e., width variation, and changing the thickness of cantilever beams. The width changing approach suffers from the deduction of output power from the piezoelectric elements of

The shear response of thirteen slender geopolymer concrete (GPC) beams reinforced with basalt fiber reinforced polymer (BFRP) bars as longitudinal reinforcements without stirrups was investigated. Different fiber combinations were used to enhance the shear capacity of the beams, including (1) single type of macro-steel fibers (SF) or (2) macro-synthetic polypropylene fibers (PF), (3) hybridization

In this paper, damped dynamic deflections of an advanced piezoelectric sandwich plate (APSP) subjected to thermo-electro-mechanical loads have been studied using a meshless method. In the considered APSP, two active piezoelectric layers are attached on to the faces of a passive advanced structure consisting of two thin graphene reinforced nanocomposite (GRNC) layers and a thick porous polymeric core

Three dimensional (3D) textiles are finding their way into fibre reinforced composite applications, and for good reasons; they can eliminate the hazard of delamination and enable complex reinforcement shapes. There is, therefore, a need for engineering methods to simulate these advanced textile structures during the product development phase. This is many times challenging since the textile architecture

The Externally Bonded Reinforcement (EBR) of timber structures with Carbon Fiber Reinforced Polymers (CFRP) is a solution that has been increasing. Like CFRP strengthened concrete structures, it is known that the premature debonding of the CFRP also occurs on timber structures. To study other alternative solutions to the EBR technique, the Near Surface Mounted (NSM) and six other situations with an