Experimental and Numerical Investigation of Shear Behavior of RC Beams Strengthened by Ultra-High Performance Concrete

Ashraf Awadh Bahraq,Mohammed Ali Al-Osta,Shamsad Ahmad,Mesfer Mohammad Al-Zahrani,Salah Othman Al-Dulaijan,Muhammad Kalimur Rahman 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.1

This paper presents a study on the shear behavior of reinforced concrete (RC) beams strengthened by jacketing the surfaces of the beams using ultra-high performance fiber reinforced concrete (UHPC). The surfaces of the RC beams were prepared by sandblasting and UHPC was cast in situ over the surfaces of RC beams. The beams were strengthened using two different strengthening configurations; (i) two longitudinal sides strengthening (ii) three sides strengthening. The bond between normal concrete and UHPC was examined by conducting splitting tensile strength and slant shear strength tests on composite cylindrical specimens cast using normal concrete and UHPC. The control and strengthened beam specimens were tested using four-point loading arrangement maintaining different shear span-to-depth ratios. The results of tested beams showed the beneficial effects of strengthening the RC beams using UHPC, as evident from enhancement of the shear capacity and shifting of the failure mode from brittle to ductile with more stiff behavior. In addition, a non-linear finite element model (FEM) was developed to examine the sufficiency of the experimental results used to study the shear behavior of control and strengthened beams. The failure loads and the crack patterns determined experimentally matched well with those predicted using the proposed model with a reasonably good degree of accuracy.

Influences of porosity distributions and boundary conditions on mechanical bending response of functionally graded plates resting on Pasternak foundation

Moustafa Guellil,Hayat Saidi,Fouad Bourada,Abdelmoumen Anis Bousahla,Abdelouahed Tounsi,Mesfer Mohammad Al-Zahrani,Muzamal Hussain,S. R. Mahmoud 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.1

In this paper, a higher order shear deformation theory for bending analysis of functionally graded plates resting on Pasternak foundation and under various boundary conditions is exposed. The proposed theory is based on the assumption that porosities can be produced within functionally graded plate which may lead to decline in strength of materials. In this research a novel distribution of porosity according to the thickness of FG plate are supposing. Governing equations of the present theory are derived by employing the virtual work principle, and the closed-form solutions of functionally graded plates have been obtained using Navier solution. Numerical results for deflections and stresses of several types of boundary conditions are presented. The exactitude of the present study is confirmed by comparing the obtained results with those available in the literature. The effects of porosity parameter, slenderness ratio, foundation parameters, power law index and boundary condition types on the deflections and stresses are presented.

Influence of porosity on thermal buckling behavior of functionally graded beams

Hichem Bellifa,Mahmoud M. Selim,Abdelbaki Chikh,Abdelmoumen Anis Bousahla,Fouad Bourada,Abdeldjebbar Tounsi,Kouider Halim Benrahou,Mesfer Mohammad Al-Zahrani,Abdelouahed Tounsi 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.4

The interest of this work is the analysis of the effect of porosity on the nonlinear thermal stability response of power law functionally graded beam with various boundary conditions. The modelling was done according to the Euler-Bernoulli beam model where the distribution of material properties is imitated polynomial function. The thermal loads are assumed to be not only uniform but linear as well non-linear and the temperature rises through the thickness direction. The effects of the porosity parameter, slenderness ratio and power law index on the thermal buckling of P-FG beam are discussed.

Buckling analysis of functionally graded plates using HSDT in conjunction with the stress function method

Ahmed Bakoura,Fouad Bourada,Abdelmoumen Anis Bousahla,Abdeldjebbar Tounsi,Kouider Halim Benrahou,Abdelouahed Tounsi,Mesfer Mohammad Al-Zahrani,S.R. Mahmoud 사단법인 한국계산역학회 2021 Computers and Concrete, An International Journal Vol.27 No.1

In this article, the mechanical buckling analysis of simply-supported functionally graded plates is carried out using a higher shear deformation theory (HSDT) in conjunction with the stress function method. The proposed formulation is variationally consistent, does not use a shear correction factor and gives rise to a variation of transverse shear stress such that the transverse shear stresses vary parabolically through the thickness satisfying the surface conditions without stress of shear. The properties of the plate are supposed to vary across the thickness according to a simple power law variation in terms of volume fraction of the constituents of the material. Numerical results are obtained to study the influences of the power law index and the geometric ratio on the critical buckling load.

Bending analysis of functionally graded plates using a new refined quasi-3D shear deformation theory and the concept of the neutral surface position

Houari Hachemi,Abdelmoumen Anis Bousahla,Abdelhakim Kaci,Fouad Bourada,Abdeldjebbar Tounsi,Kouider Halim Benrahou,Abdelouahed Tounsi,Mesfer Mohammad Al-Zahrani,S. R. Mahmoud 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.1

This paper presents a high-order shear and normal deformation theory for the bending of FGM plates. The number of unknowns and governing equations of the present theory is reduced, and hence makes it simple to use. Unlike any other theory, the number of unknown functions involved in displacement field is only four, as against five or more in the case of other shear and normal deformation theories. Based on the novel shear and normal deformation theory, the position of neutral surface is determined and the governing equilibrium equations based on neutral surface are derived. There is no stretching–bending coupling effect in the neutral surface-based formulation, and consequently, the governing equations of functionally graded plates based on neutral surface have the simple forms as those of isotropic plates. Navier-type analytical solution is obtained for functionally graded plate subjected to transverse load for simply supported boundary conditions. The accuracy of the present theory is verified by comparing the obtained results with other quasi-3D higher-order theories reported in the literature. Other numerical examples are also presented to show the influences of the volume fraction distribution, geometrical parameters and power law index on the bending responses of the FGM plates are studied.

Porosity-dependent mechanical behaviors of FG plate using refined trigonometric shear deformation theory

Tahar Hacen Lamine Bekkaye,Bouazza Fahsi,Abdelmoumen Anis Bousahla,Fouad Bourada,Abdeldjebbar Tounsi,Kouider Halim Benrahou,Abdelouahed Tounsi,Mesfer Mohammad Al-Zahrani 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.26 No.5

In this research, bending and buckling analyses of porous functionally graded (FG) plate under mechanical load are presented. The properties of the FG plate vary gradually across the thickness according to power-law and exponential functions. The material imperfection is considered to vary depending to a logarithmic function. The plate is modeled by a refined trigonometric shear deformation theory where the use of the shear correction factor is unnecessary. The governing equations of the FG plate are derived via virtual work principle and resolved via Navier solutions. The accuracy of the present model is checked by comparing the obtained results with those found in the literature. The various effects influencing the stresses, displacements and critical buckling loads of the plate are also examined and discussed in detail.

Natural frequencies of FGM nanoplates embedded in an elastic medium

Bouafia, Halima,Chikh, Abdelbaki,Bousahla, Abdelmoumen Anis,Bourada, Fouad,Heireche, Houari,Tounsi, Abdeldjebbar,Benrahou, Kouider Halim,Tounsi, Abdelouahed,Al-Zahrani, Mesfer Mohammad,Hussain, Muzama Techno-Press 2021 Advances in nano research Vol.11 No.3

The small scale impact on the vibrational properties of "functionally graded" (FG) nanoplate embedded in an elastic medium is examined. The formulation is based on the four-unknown refined integral plate theory on aggregate with the nonlocal elasticity theory. Contrary to other theories, this one involves only four unknown variables. The solution procedure is obtained by employing the motion differential equations of physical phase that are converted into set of "linear algebraic equations". After, these are solved by a computer code. The influences of aspect ratio, material index, nonlocal parameter and elastic medium stiffness on the different modal vibrations of FG nanoplate are explored. The results demonstrate the significant impact of different physical and geometrical parameters on the vibration behavior of FG nanoplate.

Physical stability response of a SLGS resting on viscoelastic medium using nonlocal integral first-order theory

Abdelkrim Rouabhia,Abdelbaki Chikh,Abdelmoumen Anis Bousahla,Fouad Bourada,Houari Heireche,Abdeldjebbar Tounsi,Kouider Halim Benrahou,Abdelouahed Tounsi,Mesfer Mohammad Al-Zahrani 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.6

The buckling properties of a single-layered graphene sheet (SLGS) are examined using nonlocal integral first shear deformation theory (FSDT) by incorporating the influence of visco-Pasternak’s medium. This model contains only four variables, which is even less than the conventional FSDT. The visco-Pasternak’s medium is introduced by considering the damping influence to the conventional foundation model which modeled by the linear Winkler’s coefficient and Pasternak’s (shear) foundation coefficient. The nanoplate under consideration is subjected to compressive in- plane edge loads per unit length. The impacts of many parameters such as scale parameter, aspect ratio, the visco-Pasternak’s coefficients, damping parameter, and mode numbers on the stability investigation of the SLGSs are examined in detail. The obtained results are compared with the corresponding available in the literature