This article presents a higher-order nonlinear finite element formulation to evaluate the nonlinear deformation of functionally graded magneto-electro-elastic porous (FG-MEEP) shells under the ...influence of electro-magnetic and mechanical loads. To derive the equations of motion, Donnell's shell theory with higher-order shear deformation theory and von-Karman's geometric nonlinearity is plugged into the principle of minimum potential energy. The credibility of the formulation is verified against published articles. The even or uneven distribution of porosity is implemented in the analysis. The coupled material properties are functionally graded according to modified power law. Two forms of material gradation such as 'B' rich bottom and 'F' rich bottom are considered. Several numerical examples are illustrated to demonstrate the influence of parameters such as shell geometry, porosity distribution, gradient index, porosity volume, functionally graded pattern, electro-magnetic loads on the nonlinear central deflection of FG-MEEP shells. Special attention has been paid to distinguish between the structural responses of FG-MEEP shells at fully coupled and uncoupled states.
The advent of additive manufacturing has brought a paradigm shift in many engineering applications involving polymer composites. The current study aims at integrating artificial neural network (ANN) ...with experimentation to assess the wear properties of glycol‐modified polyethylene terephthalate (PETG) composites reinforced with organically modified montmorillonite (OMMT) nanoclay (1%, 3%, and 5% weight percentages). The specimens are fabricated using fused deposition modeling technology. The proposed composites are compounded and developed using a single screw extruder with a diameter of 1.75 mm. As per ASTM G99 standard, the tribological characteristics were investigated using sliding wear with the dry pin on disc arrangement. The data points owing to the wear properties of PETG/OMMT nanocomposites are collected with the aid of the experimentation, which is then used to train the ANN model using Levenberg– Marquardt backward propagation algorithm. The experimental results show that adding OMMT nanoclay at a 3% weight percentage improves the wear properties of the composites compared to virgin PETG. A scanning electron microscope study of the wear mechanism reveals that adding OMMT nanoclay to the proposed composites results in mild wear as opposed to heavy wear in the case of virgin PETG. The ANN model developed to predict the tribological performance of PETG/OMMT facilitates better predictability with 99.6% accuracy, thereby reducing the requirement of expensive experimentation and analysis. The proposed composites may be applicable in the prosthetic, aerospace and automobile industries.
Experiment‐ANN methodology for wear analysis of PETG/OMMT nanoclay composites.
In this research work, an artificial neural network (ANN) based data driven prediction technique is proposed to evaluate the absorption characteristics of glycol‐modified polyethylene terephthalate ...(PETG) polymer nanocomposites reinforced with short carbon fibers (SCFs) and organically modified montmorillonite (OMMT) nanoclay (NC) fillers. The specimens are fabricated through additive manufacturing routine. The data points owing to the absorption of PETG nanocomposites are collected with the aid of the experimentation, which are then used to train the ANN model using Levenberg–Marquardt backward propagation algorithm. Different variants of PETG nanocomposites are prepared using various weight percentages of NC (1%, 3%, and 5%) and SCFs (5%, 10%, and 15%). The required filaments were prepared with the aid of compounding and extrusion processes. The specimens were printed using the fused deposition modeling technique. Further, the absorption behavior of these nanocomposites when exposed to distilled water, salt solution, and sugar solution has been experimentally studied following the ASTM D570 standard. The individual and combined effects of reinforcing OMMT‐NC and SCFs in the PETG matrix are also studied. The experimental results suggest that the absorption characteristics of PETG nanocomposites are significantly affected by the NC and SCFs reinforcements. The outcomes of this work will aid the design/material engineers in making a good trade‐off between the mechanical and absorption properties of the proposed PETG nanocomposites.
In this study, the experimental results of the modal analysis of additive manufactured glycol‐modified polyethylene terephthalate (PETG) based composites reinforced with short carbon fibers and ...organically modified montmorillonite (OMMT) nanoclay (NC) is presented. The raw materials are compounded and extruded using the twin‐screw extruder. The specimens in the beam form are prepared through the fused deposition modeling process, one of the prominent additive manufacturing techniques. The individual and combined effect of reinforcing OMMT nanoclay and short carbon fibers on the natural frequencies and damping factors of PETG composite is investigated by varying their weight percentages. Further, a comparative study is made with the vibration response of pure PETG beam as well. The experimental set‐up constituted of an accelerometer, impact hammer, and data acquisition unit is used for vibration studies. Two different boundary conditions, viz. cantilever and clamped constraints, have been incorporated in this investigation. The experimental results reveal that boundary conditions and the weight percentage of reinforcements play a vital role in deciding the frequency and damping parameters of the PETG composite beam.
This work aims to assess the nonlinear free vibration characteristics of multifunctional sandwich composite plates with auxetic core and magneto-electro-elastic (MEE) facesheets. The novelty of this ...work is that the combined effects of the electromagnetic (EM) circuits, micro-topological arrangements of MEE material on the coupled frequency response of multifunctional sandwich composite plates with auxetic cores has been investigated for the first time. To this end a higher order finite element (FE) formulation has been developed. The global equations of motion are arrived through Hamilton's principle and Reddy's higher order shear deformation theory (HSDT). The C
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continuity requirement of HSDT is fulfilled by considering second order derivative terms as higher order rotational degrees of freedom. Hence, the computational efficiency of this unique FE formulation is found to be better than the commercial numerical software in terms of computational time and costs. Also, the multi-physics field interactions are accurately established. In addition, emphasis has been placed on the geometrical skewness as well which is cumbersome to evaluate through the analytical modeling. Special attention is paid on assessing the influence of coupling fields and EM circuits associated with the auxetic inclination angle, skew angle, micro-topological arrangement of MEE facesheets, core-to-facesheet thickness ratio, length-to-thickness ratio and mechanical boundary conditions on the natural frequency of multifunctional sandwich composite plates, which is first of its kind.
This work presents a detailed investigation of the effect of auxeticity synergised with the pyro-coupling behaviour of multiphase magneto-electro-elastic (M-MEE) composites using a finite element ...(FE) framework. The nonlinear deflection and bending problems of sandwich plates with auxetic core and M-MEE skins subjected to multi-physics load (electric, magnetic and thermal) are probed. The plate kinematics is governed by Reddy’s higher-order shear deformation theory (HSDT). The nonlinear relation between the strains and displacements is established through von-Karman’s nonlinear relations. The temperature profiles are considered linearly and nonlinearly varying across the thickness of the plate. Various parametric studies presented in this article highlight the influence of the auxetic cell inclination angle, rib-length ratio, rib thickness, the plate-to-core ratio etc., associated with the pyro-coupling on the nonlinear deflection and bending of sandwich plates. The results reveal that the plate deflection, bending behaviour and degree of pyro-coupling significantly depend on the auxetic unit cell dimensions and magnitude of electro-magnetic loads. The significant influence of temperature profiles on the pyro-coupling are witnessed at lower auxetic cell angle. The nonlinear deflections of the sandwich plate and hence the potentials developed tend to improve with the lower values of plate-to-core ratio and rib thickness. The prominent outcomes of this work related to integrated effects of auxeticity and pyro-coupling are not yet reported in the open literature and are deemed to be utilised as a future reference.
This research focuses on evaluating the combined effects of the interphase of the three-phase magneto-electro-elastic (TPMEE) composites and carbon nanotubes (CNTs) agglomeration on the nonlinear ...deflection of the multifunctional sandwich plate, using an artificial neural network (ANN) assisted finite-element (FE) approach. The data points collected from the in-house developed FE computational tool are used to train the ANN model. To this end, a backpropagation-based Levenberg–Marquardt algorithm is used. The core of the plate is made of agglomerated CNTs, and the facesheets are made of TPMEE composites. Two different agglomeration states, partial and complete, are considered for evaluation. Also, three variations of CNTs arrangement are assumed. On the other hand, the interphase effects are incorporated through its volume fractions and compositions. The plate kinematics is based on the higher-order shear deformation theory, and the nonlinearity is assumed to follow von Karman's strain-displacement relation. The equations of motion are derived using the total potential energy principle. Finally, the direct iterative method is used to arrive at the solutions. The numerical examples are also provided to understand the influence of coupling fields associated with the parameters, such as agglomeration, interphase volume fraction, interphase compositions and CNTs arrangement.
In this article, a first attempt has been made to address the nonlinear deflection problem of magneto-electro-elastic shells reinforced with carbon nanotubes subjected to multiphysics loads like ...mechanical, electric and magnetic loads. In this regard, a mathematical model based on higher-order shell theory, von-Karman's nonlinearity is derived using finite element platform. The true flexural behavior of the functionally graded carbon nanotube reinforced magneto-electro-elastic shell under the action of individual/combined multiphysics loading is captured through higher-order nonlinear terms. Meanwhile, the results of this article emphasize on understanding the influence of coupling fields in conjunction with material and geometrical parameters on the deflection of functionally graded carbon nanotube reinforced magneto-electro-elastic shells. In addition, the study provides an intensive and meticulous insight into the deflection of curved shells with respect to different shell geometry, carbon nanotube distributions, carbon nanotube volume fractions, aspect ratio, thickness ratio, shallowness ratio, and electro-magnetic loads. The study is believed to pave way for extensive further studies on these classes of materials which can prove to be instrumental in various avenues of aerospace research and development.
In this article, finite-element formulation based on higher order shear deformation theory (HSDT) is proposed to evaluate the nonlinear frequency characteristics of carbon nanotube reinforced ...magneto-electro-elastic (CNTMEE) plates. The special emphasis has been made on investigating the effects of electro-magnetic circuits on the nonlinear coupled behaviour of CNTMEE plates, for the first time in the literature. The von-Karman type of nonlinear strain–displacement relations is assumed. The nonlinear fundamental frequencies for a given maximum transverse deflection are obtained through direct iterative method. Also, different forms of functionally graded CNT distributions are considered and compared with that of uniformly distributed CNT arrangement. Several numerical illustrations are depicted to highlight the influence of parameters such as electro-magnetic conditions, CNT volume fraction, boundary conditions, aspect ratio, length-to-thickness ratio etc. One of the major outcomes of this study is the influence of coupling fields on the nonlinear frequency response of CNTMEE plates.
This study presents an innovative approach utilizing Artificial Neural Network (ANN) strategies to evaluate the energy absorption capabilities of eco‐friendly rubber crumb/kenaf composites subjected ...to low‐velocity impact loads. The primary objectives of this research were to assess the energy absorption characteristics of these sustainable composites, understand their mechanical behavior under the impact, and provide valuable insights into their potential applications. To achieve these objectives, an experimental methodology was employed. Rubber crumb/kenaf composites with varying compositions were prepared, and low‐velocity impact tests were conducted using a drop‐weight impact testing apparatus to assess their energy absorption behavior and these parameters were used as inputs for training the ANN models. The weight percentage of waste tire rubber particle (WTRP), type of impactor and impact energies are considered as input data, whereas the absorbed energy is treated as the output. Through the advanced ANN strategies, accurate predictions of energy absorption performance were achieved for the rubber crumb/kenaf composites. The Levenberg–Marquardt optimisation algorithm with ten neurons and a tangent sigmoid activation function is used to train the ANN model. The trained ANN model is tested on an unseen dataset, different from the training data. It is shown to accurately predict the energy absorption characteristics of WTRP/KRE composites with a maximum error of 4.54%. The results revealed that the composite's energy absorption capabilities were influenced by the ratio of rubber crumb to kenaf, as well as the impact velocity. Additionally, the ANN models demonstrated excellent predictive capabilities, enabling efficient estimation of energy absorption behavior. The significance of these results lies in the potential applications of eco‐friendly rubber crumb/kenaf composites. By understanding their energy absorption characteristics, these composites can be effectively utilized in various industries. For instance, they could be employed in automotive parts manufacturing to enhance occupant safety during low‐velocity impact events. Furthermore, these composites can find applications in sports equipment, protective gear, and other impact‐prone products, contributing to sustainable and environmentally friendly materials. It is believed that by adopting the proposed ANN methodology, the experimentation costs and time can be significantly reduced without compromising the accuracy of the results. The obtained results provide valuable insights into the mechanical behavior of these sustainable composites and open avenues for their implementation in diverse industries where impact resistance is crucial
Highlights
Development of sustainable Rubber crumb/kenaf composites
Application of advanced ANN based predictive assessment of the impact response
Parametric study of impactor shape and height of impact is performed
The damage mechanism contributing to energy absorption is micrographically studied
Experimental‐ANN based energy absorption prediction methodology
