Sudip Dey

National Institute of Technology, Silchar | NIT Silchar · Department of Mechanical Engineering

This paper presents the effect of rotational speeds on free vibration characteristics of delaminated twisted graphite–epoxy cross-ply composite conical shells employing finite element method. Theoretical formulation is based on Mindlin's theory considering an eight noded isoparametric plate bending element. A generalized dynamic equilibrium equatio...

In this paper, the finite element method is employed to investigate the effects of delamination on free vibration characteristics of graphite–epoxy pretwisted shallow angle-ply composite conical shells. The generalized dynamic equilibrium equation is derived from Lagrange’s equation of motion neglecting Coriolis effect for moderate rotational speed...

This paper presents the time dependent response of multiple delaminated angle-ply composite pretwisted conical shells subjected to low velocity normal impact. The finite element formulation is based on Mindlin’s theory incorporating rotary inertia and effects of transverse shear deformation. An eight-noded isoparametric plate bending element is emp...

This paper presents a finite element method to compare the effects of delamination on free vibration of graphite-epoxy bending stiff and torsion stiff composite pretwisted shallow conical shells. The generalized dynamic equilibrium equation is derived from Lagrange’s equation of motion neglecting the Coriolis effect for moderate rotational speeds....

In this paper, a finite element method is employed to investigate the free vibration characteristics of single and multiple delaminated graphite-epoxy quasi-isotropic composite conical shells. The generalized dynamic equilibrium equation is derived from Lagrange’s equation of motion neglecting Coriolis effect for moderate rotational speeds. The for...

The large compositional space of high entropy alloys (HEA) often presents significant challenges in comprehensively deducing the critical influence of atomic composition on their mechanical responses. We propose an efficient nonparametric kernel-based probabilistic computational mapping to obtain the optimal composition of HEAs under ballistic cond...

Design of high entropy alloys (HEA) presents a significant challenge due to the large compositional space and composition-specific variation in their functional behavior. The traditional alloy design would include trial-and-error prototyping and high-throughput experimentation, which again is challenging due to large-scale fabrication and experimen...

Motivated by the recent discoveries concerning the exceptional surface engineering capabilities offered by high-entropy alloys (HEAs), this article investigates the tribological behaviour of pristine and graphene (Gr) nano-engineered AlxCoCrFeNi HEA. The atomic scale scratching is performed for different configurations of HEA in a molecular dynamic...

In the present study, a set of molecular dynamics (MD) simulations are carried out to investigate the effect of individual alloying elements on the mechanical deformation of AlCoCrFeNi high entropy alloy (HEA). Different HEA system configurations were considered by varying the atomic fraction (at.%) of the individual alloying elements. The shear st...

This study employs a series of molecular dynamics (MD) simulations to investigate the atomistic deformation mechanism of graphene (Gr)-coated Al[Formula: see text]CoCrFeNi high-entropy alloy (HEA) during nanoindentation. In the elastic region, both substrates exhibit similar indentation performance. However, at greater indentation depths, the Gr-co...

Carbon nanotubes are drawing wide attention of research communities and several industries due to their versatile capabilities covering mechanical and other multi-physical properties. However, owing to extreme operating conditions of the synthesis process of these nanostructures, they are often imposed with certain inevitable structural deformities...

This paper portrays the natural frequencies and mode shapes of composite circular plate being inspired from the construction of annual rings at stem of the tree. This bio-inspired concentric circular orientation of fibers unlike annual ring model can be utilized as structural components of engineering systems. Each layer of concentric circular fibe...

PurposeThe present paper proposes to explore the fundamental natural frequencies of a porous functionally graded material (FGM) plates. The effect of porosity in an FGM structure is studied in an uncertain quantification domain.MethodA finite element model is developed considering isoperimetric quadratic element and evaluating the first three natur...

The conventional design process of journal bearings is completely based on deterministic theoretical predictions. The deterministic approach ignores the probabilistic and random nature of input variables and consequently, poses an arbitrary tolerance or safety factor on the performance parameters. However, such arbitrary safety factors result in pe...

Wire Electric Discharge Machining (WEDM) involves a high degree of nonlinearity and stochastic phenomena due to its complexity and process anisotropy. Thus, prediction of WEDM performances must be carried out through an efficient tool. The choice of data clustering technique in adaptive neuro-fuzzy inference system (ANFIS) is crucial since it has a...

The article is aimed to explore the futuristic potential of uncertainty quantification (UQ) as an essential course in engineering studies in the curriculum of undergraduate studies. In this context, a brief review is carried out to reveal the immense growing interest in the field of uncertainty analysis. Based on this, the essential topics to be co...

Motivated by recent discoveries concerning the extreme superiority of multilayer graphene in terms of kinetic energy dissipation compared to conventional monolithic materials, this article investigates the ballistic performance and physics-informed strategic sequencing of graphene-reinforced aluminum laminates under the influence of random disorder...

This paper presents the surrogate-based predictive dynamic behavior of hybrid functionally graded sandwich cylindrical shells. The material properties are graded based on the power law for functionally graded structures to comply with high strength and stiffness at an elevated temperature. At the same time, the sandwich composite is employed to ens...

WEDM is efficient in machining complicated profiles with high dimensional accuracy. The Nickel-aluminum-bronze (NAB) is a high-strength alloy with exceptional corrosion-resistant properties and is abundantly used in marine applications such as propellers, valves, and seawater pumps. The previous literature reports numerous instances of WEDM-induced...

In the present article, we explored the ballistic behaviour of bilayer graphene (BLG) by performing a series of molecular dynamics (MD) simulations. The computationally expensive nature of large scale MD simulations frequently hinders a thorough understanding of material characterization. To mitigate this lacuna we demonstrated the successful integ...

This chapter presents the stochastic low-velocity impact responses of a cantilever plate composed of functionally graded materials (FGM) by employing the radial basis function (RBF) model. A novel algorithm is developed to ascertain the stochastic transient impact responses experienced by the FGM plates due to the central impact of a spherical stee...

Wire electric discharge machining (WEDM) has gained tremendous market share due to its potential to create complex profiles and ease in machining exotic materials. The inherent problem of wire lag, however, has a significant impact on the accuracy and precision of complex profiles in WEDM. Furthermore, if parametric uncertainties are not taken into...

The present study outlines the stochastic framework to address the dynamic behavior of the porous functionally graded cantilever plates. The intrusive variability in the fundamental material properties of the porous structures composed of functionally graded materials (FGM) influences the system's desired operational behavior. This creates a strong...

PurposeThe vibration characteristics of the beam depend upon its uniformity, material density, and presence of any defects like cracks. The present study investigated the vibration characteristics of a cracked cantilever beam comprised of structural steel and E-glass fiber using ANSYS 18.1 FEA software.Method The effect of crack parameters, such as...

First-order shear deformation theory (FSDT) is less accurate compared to higher-order theories like higher-order zigzag theory (HOZT).In case of large-scale simulation-based analyses like uncertainty quantification and optimization using FSDT, such errors propagate and accumulate over multiple realizations, leading to significantly erroneous result...

PurposeThe aim of this paper is to quantify the stochastic effect for functionally graded (FG) plate in conjunction to free vibration and impact loading.Method The variabilities in geometric and materials properties are considered. A support vector machine (SVM) is employed to construct the surrogate model. The constructed model portrays significan...

Attaining improved level of process performance in wire-electro discharge machining (WEDM) at any particular parametric condition is always a complicated task due to the inherent nature of the process. Endeavour to improve one performance measure is always done at the cost of the remaining performance measures. Amongst the performance measures, mat...

This article reflects the effect of relative thickness of various components of hybrid structures on random natural frequencies of hyperbolic paraboloid shells. The total thickness, other geometrical parameters and the material properties are kept constant. Here, the hybrid shell structure is composed of three different components: laminated compos...

Stochastic first-ply failure analysis of a carbon-epoxy-based laminated composite plate is conducted based on Monte Carlo simulation (MCS) and moving least squares (MLS)-based surrogate model. A five-noded finite element (FE) model is developed to determine the deterministic first-ply failure load. The inherited randomness in the geometrical proper...

Randomness in the media breaks its periodicity affecting the vibration and wave propagation performance. Such disorder caused by the variability may lead to interesting physical phenomena such as trapping and scattering waves, wave reflection, and energy localisation. While the randomness may be attributed to manufacturing irregularities and quantify...

Purpose: This paper presents the sensitivity analysis (SA) of the random natural frequency responses of hybrid multi-functionally graded sandwich (HMGS) shells for establishing a unified measure in the case of multi-objective performances. The functionally graded materials, laminated composites, and sandwich cores are employed to develop such novel...

In structural applications, laminated composites are typically the best choice for providing a high strength-to-weight ratio. The composite laminates, on the other hand, are susceptible to the first ply failure (FPF), which can result in delamination, matrix cracking, and fibre breaking. As a result, it's critical to map the FPF of laminated compos...

The present article outlines a probabilistic investigation of the uniaxial tensile behaviour of twisted bilayer graphene (tBLG) structures. In this regard, the twist angle (θ) and temperature (T) are considered as the control parameters and the ultimate tensile strength (UTS) and failure strain of the tBLG structures are considered as the responses...

The current study aims to investigate the different geotechnical characteristics of soil stabilization with the addition of lime and RHA in varying amounts (Lime %: 3, 5, 7, 9; and RHA %: 4, 8, 12, 16). A series of compaction, unconfined compressive strength (UCS), California bearing ratio (CBR), pH, and XRD tests are performed in the laboratory to...

The present report outlines a probabilistic investigation of the temperature dependent resonant frequency of various BNNT and CNT-based hetero-junctions and Van der Waals (VdW) heterostructures. In the preliminary analysis, the vibrational behaviour of the considered heterostructures is evaluated by taking into account the degree of heterogeneity,...

Graphene is one of the strongest, stiffest, and lightest nanoscale materials known to date, making it a potentially viable and attractive candidate for developing lightweight structural composites to prevent high-velocity ballistic impact, as commonly encountered in defense and space sectors. In-plane twist in bilayer graphene has recently revealed...

The present paper proposes a surrogate-assisted moment-independent stochastic sensitivity analysis of laminated composite plates for establishing a unified measure in the case of multi-objective performances. With the advancements in artificially engineered structural systems spanning across different length scales, it has become more common to des...

We present herein a polynomial chaos-Kriging (PC-Kriging)-based molecular dynamics (MD) simulation framework of twisted bilayer graphene (tBLG) structures to investigate the influence of stochastic parametric variations on their nano-indentation behaviour. The relative rotation angle (RRA) and operating temperature were taken as input parameters, w...

The characterization of nano-scale materials in the lab setting requires a huge cost, precision and time. The molecular simulations rule out the cost and precision but still these simulations are computationally expensive and intensive. In this regard, we present a support vector machine (SVM)-based molecular dynamics simulation of monolayer graphe...

This paper showcases the outcome of thickness on probabilistic natural frequencies of hybrid functionally graded (FG)-sandwich materials with cylindrical shell geometry. The top facesheet of the sandwich structure is replaced by functionally graded material, while the bottom facesheet is that of laminated composites. An eight noded isoperimetric qu...

The wire electric discharge machining (WEDM) is a potential alternative over the conventional machining methods, in terms of accuracy and ease in producing intricate shapes. However, the WEDM process parameters are exposed to unavoidable and unknown sources of uncertainties, following their inevitable influence over the process performance features...

Superalloys are categorized as difficult to process materials with a broad spectrum of applications in industries. Process modeling and optimization of WEDM performances on nickel- and titanium-based superalloys are widely investigated. However, such investigations on iron-based superalloy are still lacking and hence probed in the present article....

Molecular dynamics (MD) simulations have emerged to be a vital tool for the analysis of nanoscale materials like graphene. However, reliability of the results derived from MD simulations depends on the adopted inter-atomic potential (IP), which is mathematically fitted to the data obtained from first principle approaches or experiments. There exist...

The present study deals with analysing the dynamic behaviour of a smart beam coupled with piezoelectric materials in the unimorph and bimorph configurations connected to resonant shunt circuits. The resonant shunt circuit connection is applied to promote and passively modulate the vibration and flexural wave propagation attenuation. A Spectral Elem...

A machine learning assisted efficient, yet comprehensive characterization of the dynamics of coronaviruses, in conjunction with finite element (FE) approach, is presented. Without affecting the accuracy of prediction in low‐frequency vibration analysis, an equivalent model for the FE analysis is proposed, based on which the natural frequencies corr...

Despite the tremendous capabilities of Molecular dynamics (MD) simulations, they suffer from the limitation of computationally intensive and time-consuming nature. This hinders the seamless discovery of nanomaterials with adequate computational insights. Over the last decade, graphene has received widespread attention from the scientific community...

This paper presents the effect of thickness on probabilistic buckling load of sandwich plate using radial basis function (RBF) approach. Due to inevitable material anisotropy and manufacturing inaccuracy such type of structure are always subjected to spatial variability. So, it is required to consider the stochastic effect which makes computational...

The present paper deals with the stochastic natural frequency analysis of functionally graded material (FGM) plates by employing the multivariate adaptive regression splines surrogate (MARS) model. The gradation of material properties of constitute materials is carried out by power law distribution. The variation in material properties for differen...

Superalloys are categorized as difficult to process materials with a broad spectrum of applications in industries. Process modeling and optimization of Wire Electric Discharge Machining (WEDM) performances on Nickel and Titanium based superalloys are widely investigated. However, such investigations on Iron-based Superalloy are still lacking and he...

The present chapter investigates the moment-independent sensitivity analysis for hybrid sandwich structures (having cylindrical shell geometry) subjected to low-velocity impact. These hybrid structures are extensively used in lightweight applications where thermal exposure/resistance is of prime importance. Here, the FG facesheet is placed at the u...

The utility of carbon nanotubes as the reinforcement agents in polymer and metal matrix composites has opened up a new avenue in the development of novel composite materials with exceptional strength and stiffness to weight ratios. Such exploitation of superior mechanical properties of carbon nanotubes depends on their inherent irregularities and s...

The manufacturing and fabrication of complex polymer sandwich composite plates involve various processes and parameters, and the lack of control over them causes uncertain system parameters. It is essential to consider randomness in varying parameters to analyse polymer sandwich composite plates. The present study portrays uncertainty quantificatio...

This paper presents the effect of temperature on stochastic natural frequencies of cylindrical shells, composed of functionally graded materials (FGM) by using machine learning quadratic Support Vector Machine (SVM). An eight noded isoperimetric quadratic element is considered for the finite element formulation. The power law is employed to constru...

Due to the absence of adequate control at different stages of complex manufacturing process, material and geometric properties of composite structures are often uncertain. For a secure and safe design, tracking the impact of these uncertainties on the structural responses is of utmost significance. Composite materials, commonly adopted in various m...

In this paper, uncertainty quantification in natural frequencies for laminated soft core sandwich plates is presented by employing finite element (FE) coupled polynomial neural network (PNN) approach. The computational efficiency and accuracy is achieved by using PNN as surrogate model. Latin hypercube sampling method is employed for training of da...

This study presents the effect of skewness in natural frequency responses of sandwich plates. The free vibration analysis is carried out by using higher order zigzag theory (HOZT) considering random input parameters. It satisfies the transverse shear stress continuity condition and the transverse flexibility effect. The in-plane displacement throug...

Doping in pristine 2D materials brings about the advantage of modulating wide range of mechanical properties simultaneously. However, intrinsic defects (such as Stone-Wales and nanopore) in such hybrid materials are inevitable due to complex manufacturing and synthesis processes. Besides that, defects and irregularities can be intentionally induced...

This paper quantifies the influence of uncertainty in the low-velocity impact responses of sandwich plates with composite face sheets considering the effects of obliqueness in impact angle and twist in the plate geometry. The stochastic impact analysis is conducted by using finite element (FE) modelling based on an eight nodded isoparametric quadra...

The present paper portrays the mapping for stochasticity in low-velocity impact responses of functionally graded material (FGM) plates by employing multivariate adaptive regression splines (MARS) surrogate model in conjunction with finite element (FE) approach. The unavoidable stochastic variabilities (caused due to numerous errors involved in manu...

The initiation and propagation of uncertainties in structural behaviour of complex anisotropic sandwich structure has significant computational challenges. Due to limitation of experimental data, probabilistic descriptions of uncertain parameters are not practically feasible to expedite. This paper presents the prediction capability of surrogate mo...

This paper deals with the stochastic sensitivity analysis of functionally graded material (FGM) plates subjected to free vibration and low-velocity impact to identify the most influential parameters in the respective analyses. A hybrid moment-independent sensitivity analysis is proposed coupled with the least angle regression based adaptive sparse...

This paper deals with portraying the stochastic natural frequencies of cantilever plates made up of functionally graded materials (FGMs) by employing the radial basis function (RBF)-based finite element (FE) approach. The material modeling of FGM plates is carried out by employing three different distribution laws, namely power law, sigmoid law, an...

This article presents a concise overview on condition monitoring and retrofitting/ strengthening of structures including a practical case study of strengthening for an existing historical building. Condition assessment of an existing structure is required mainly to check serviceability and safety requirements of the structure after short term event...

The stochastic buckling behaviour of sandwich plates is presented considering uncertain system parameters (material and geometric uncertainty). The higher-order-zigzag theory (HOZT) coupled with stochastic finite element model is employed to evaluate the random first three buckling loads. A cubic in-plane displacement variation is considered for bo...

Over the last few decades, uncertainty quantification in composite materials and structures has gained a lot of attention from the research community as a result of industrial requirements. This book presents computationally efficient uncertainty quantification schemes following meta-model-based approaches for stochasticity in material and geometri...