Extensive literature on the analysis of sandwich FGM structures highlights the use of these structures as structural elements. In the present work, a detailed study has been carried out regarding the ...application of different methods and theories available in the literature for analyzing sandwich FGM structures under different loading conditions. The literature survey is carried out for sandwich FGM plates, beams, and shells. Effects of porosities, hygrothermal loadings, and structures resting on elastic foundations are also included during the review. Available manuscripts are categorized based on theories, material homogenization rules, and methods available for analysis in literature. The present review work will set a benchmark for future studies for carrying out further research in a similar direction.
Female genital mutilation/cutting (FGM/C), due to its regional occurrence, is a marginalized issue in the international arena. The aim of the study was to verify reasons for performing a procedure ...prohibited by international and domestic law. A cross-sectional study was conducted among nurses and doctors practicing in the UAE. The study was conducted from the 1 of January 2020 to the 31 of December 2021. The total number of recruited individuals who agreed to participate was 120, with the rate of return being 82%. About half of the participants (
= 59, 49.2%) have seen FGM/C patients in their UAE practice. Regarding medical staff, the total knowledge score concerning possible complications of the performed procedure was assessed at 64%, i.e., at a moderate level. None of our study participants had previously performed any type of FGM/C. However, 6.7% were willing to do it upon a mother's or guardian's request. About 83% of study participants stated that FGM/C should be halted internationally. Only 26.7% of the medical practitioners were aware of UAE law concerning FGM/C, while 50% had no knowledge concerning this issue. The present study reveals that cultural conditions take priority over medical knowledge, making medical practitioners inclined to accept the circumcision of girls and women. The crucial goals of future activities should focus on sensitizing society and the medical community, the need to create clear laws penalizing the practice, and the legal obligation to report the circumcision of a girl or woman.
In this article, the free vibration and buckling of multi-directional porous FGM sandwich plates are investigated. The material properties of FGM sandwich plates are assumed to be varying ...continuously in the longitudinal and transverse direction. The material properties are evaluated based on Voigt’s micro-mechanical model considering power law distribution method with arbitrary power index. Equilibrium equations for the vibration and buckling analysis of porous multi-directional FGM sandwich plate are obtained based on sinusoidal shear deformation theory. Analytical solution for simply supported multi-directional porous FGM sandwich plate is carried out using Navier’s solution technique. The FGM sandwich plate considered in this work has a homogeneous ceramic core and two functionally graded face sheets. To incorporate porosity in the FGM face sheet, even, uneven, logarithmic uneven, linear uneven, and sinusoidal uneven porosity distribution models are considered and analyzed. Influence of volume fraction index in the longitudinal and transverse direction, layer thickness, porosity models, porosity coefficient, and geometrical parameter over natural frequency and critical buckling load of multi-directional FGM sandwich plate is investigated.
The free vibration response of rotating pretwisted functionally graded (FG) conical shells in nonlinear thermal conditions is investigated using a finite element approach with the purpose of ...application in turbomachinery blades. With the aid of power, exponential, and sigmoid laws, the pretwisted conical shell is functionally graded in its transverse direction. The distribution of both even and uneven porosity is considered. The one-dimensional Fourier heat conduction equation is used to assess the nonlinear temperature distribution across the thickness of the FG conical shell. Lagrange’s equation is used to obtain the dynamic equation of motion of the rotating pretwisted FG conical shell. The proposed finite element model employs an eight-noded isoparametric shell element with five degrees of freedom per node. The effect of several factors, including porosity, temperature, twist angle, and rotational speed on the free vibration response of the FG porous conical shell has been investigated. The findings reveal that the porosity volume fraction has a significant influence on the natural frequency. The nonlinear temperature difference and pretwist angle both cause stiffness reduction to the FG conical shell upon increasing, whereas the presence of rotational speed inducts geometrical stiffness resulting in centrifugal stiffening.
•Min-max stress formulation is adopted to explore FGM potential on stress mitigation.•Almost fully stressed designs are attained which excel in strength performance.•Lower stresses are achieved for ...higher difference between base materials properties.•Functionally graded materials obtainable by addictive manufacturing.
The rising cost of natural resources and environmental concerns motivate systematic design and manufacture of more efficient structures. For that purpose, topology optimization has been appealing, as well as working on an enlarged design space to include multi-material solutions. The resulting optimal designs can be materialized using multi-material additive manufacturing. In the present framework, multi-material printed parts or layouts can be envisaged as having better strength properties than single-material counterparts.
The maximum von Mises stress is minimized inside a design domain through topology changes and material selection. The selected composite material model encompasses either the classical arrange of two discrete materials with sharp interfaces, or their mixture controlled by the volume fraction of each base material to generate a Functionally Graded Material (FGM). An optimized continuous variation of properties makes the FGM appealing to mitigate stress concentrations. To adequately capture the physics of mixtures considering the FGM’s mechanical properties, one uses the RAMP interpolation scheme within the Hashin-Shtrikman bounds.
A set of plane stress benchmarks are proposed. It is shown that considerably lower stress peaks on the evaluated structures can be obtained on the account of introducing more than one solid phase, specifically in the case of FGM solutions.
Over 200 million women and girls worldwide have suffered from the partial to total removal of external female genitalia for nonmedical purposes, referred to as female genital mutilation (FGM). ...Survivors of FGM may develop debilitating physical and psychological long-term sequelae. This is the first study to examine the scope of the extant surgical literature on the management of FGM-related morbidity.
A systematic scoping review of five major research citation databases was conducted.
A total of 190 articles from 29 countries met the inclusion criteria. The majority (76%) were primary source articles and from obstetrics and gynecology literature (71%). Reported interventions for FGM-related morbidity were defibulation, cyst excision, clitoral and vulvar reconstruction, urological reconstruction, peripartum procedures, labial adhesion release, and reinfibulation.
Surgery for FGM complications spans multiple specialties, which suggests multidisciplinary collaboration benefit. Plastic and reconstructive surgeons have a clear role in the multidisciplinary care team for these patients. This scoping review identified a paucity of high-quality evidence with respect to functional quality of life outcomes and long-term follow-up.
The formulations of the complete solutions to the rectangular simply supported plates with power-law, sigmoid, and exponential FGMs have been derived in Part I. In this part, we focus on the ...numerical solutions evaluated directly from theoretical formulations and calculated by finite element method using MARC program. The effects of loading conditions, the change of Poisson’s ratio, and the aspect ratio on the mechanical behavior of an FGM plate are discussed. Besides, a comparison of the results of P-FGM, S-FGM, and E-FGM is investigated.
A novel quasi-3D hyperbolic theory is presented for the free vibration analysis of functionally graded (FG) porous plates resting on elastic foundations by dividing transverse displacement into ...bending, shear, and thickness stretching parts. The elastic foundation can be chosen as Winkler, Pasternak or Kerr foundation. Three different patterns of porosity distributions (including even and uneven distribution patterns, and the logarithmic-uneven pattern) are considered. A Galerkin method is developed for the solution of the eigenvalue problem of the presented quasi-3D hyperbolic plate model. The presented quasi-3D hyperbolic theory is simple and easy to implement since it uses only five-unknown variables to determine fourfold coupled (axial-shear-bending-stretching) vibration responses. A comprehensive parametric study is carried out to assess the effects of volume fraction index, porosity fraction index, stiffness of foundation parameters, mode numbers, and geometry on the natural frequencies of imperfect FG plates.
This work presents an effective approach to investigating the buckling and post-buckling behavior of porous FGM plates. The main objective of the present analysis is to use a High Order Continuation ...based on the Asymptotic Numerical Method with the Finite Element Method for nonlinear behaviors of a Porous Functionally Graded Material plate (PFGM) with different porosity distributions under various types of transverse loads. In our study, we will take into account the lack of uniform and non-uniform porosity using a Higher-order Shear Deformation Theory (HSDT). The adapted solver proves to be more effective for analyzing non-linear mechanical phenomena and more precisely the post-buckling analysis of the PFGM plates. Indeed, this numerical high order algorithm presents an adaptive step length to the local nonlinearity of the solution branch and to detect easily the bifurcation points and bifurcated branches. When compared to iterative techniques like Newton–Raphson, the proposed high-order algorithm has the benefit of speeding up the resolution of nonlinear problems. The mathematical formulation is based on the higher-order shear deformation plate theory taking into consideration geometrical nonlinearity and initial imperfections. Numerical results of a parametric study on the effect of various types of load, porosity distribution, grading index, porosity index and different span-to-thickness ratios will be investigated.
•A High Order Continuation is applied to solve nonlinear buckling of porous FG plates.•Effects of various types of loads, porosity distribution, grading index, porosity index and different span-to-thickness on the critical buckling loads of a porous FG plates were examined.•A finite element model is used in the framework of Higher Order Shear Deformation Theory.
In this paper, two-stage approaches are proposed to study damage detection, localization and quantification in Functionally Graded Material (FGM) plate structures. Metal and Ceramic FGM plates are ...considered using three different composite materials: Al/Al2O3, Al/ZrO2-1, and Al/ZrO2-2. The FGM plates are modelled using IsoGeometric Analysis (IGA), which is more efficient than the classical Finite Element Method (FEM). Using a power-law distribution of the volume fractions of the plate constituents, the material properties of the plates are expected to vary continuously through their thickness. Improved damage indicator based on Frequency Response Function (FRF) is employed to predict the damaged elements in the first stage. A robust and efficient Improved Artificial Neural Network using Arithmetic Optimization Algorithm (IANN-AOA) is implemented for damage quantification problem in the second stage. The main idea is based on eliminating the healthy elements from the numerical model by the improved indicator. Next, collected data from damaged element based on damage index of an improved indicator is used as input and damage level as output. To prove the robustness of IANN-AOA, a Balancing Composite Motion Optimization (BCMO) is considered to improve ANN (IANN-BCMO) and is used for comparison. The results show that the improved indicator can predict the damaged elements with high precision. For damage quantification, IANN-AOA provides more accurate results than IANN-BCMO.
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