In order to better understand the interfacial debonding behavior of pipe joints during the whole loading process, an analytical solution for the full-range behavior of adhesively bonded pipe joints under combined thermal and mechanical tensile loadings is presented in this paper. The solution was developed based on a simplified rigid-softening bond–slip model, and two cases with different softening

This paper presents the node-based smoothed finite element method with linear strain functions (NS-FEM-L) for solving contact problems using triangular elements. The smoothed strains are formulated by a complete order of polynomial functions and normalized with reference to the central points of smoothing domains. They are one order higher than those adopted in the finite element method (FEM) and the

A package solution is presented for the full-scale bounds estimation of temperature in the nonlinear transient heat transfer problems with small or large uncertainties. When the interval scale is relatively small, an efficient Taylor series expansion-based bounds estimation of temperature is stressed on the acquirement of first and second-order derivatives of temperature with high fidelity. When the

Linear equation solvers require considerable computational time in many computer simulation methods, such as the stress analysis using the finite element method (FEM), or the fluid dynamics using an implicit time integration scheme. Because of their favorable nature to modern supercomputers, Krylov-type linear equation solvers have become dominant. Krylov-type solvers are usually used with preconditioners

An efficient dynamic load identification method for nonlinear structures is proposed. Assuming that the nonlinear elements of a structure can be separated, or the structural kinetic equation can be available, the whole structural damping and stiffness matrices can be divided into linear and nonlinear sub matrices. Regarding the effects of the nonlinear elements on the linear ones as dynamic load constraints

Changes in the thermomechanical properties of fiber-reinforced concrete (FRC) exposed to fire are fundamentally affected by the type and volume fraction of fibers. Because the loss of FRC load-bearing capacity is mainly caused by structural damage, a new numerical procedure based on a modified method of discontinuous boundary elements (DBEM) is proposed, which is modified to include thermomechanical

This work is about a heat transfer phenomenon in relation to the periodically laminated composite. The specific type of thermal loading, analyzed in this paper, require formulation of Robin boundary conditions. To consider a layered structure of analyzed composite, the tolerance averaging technique is used. This method allows to take into account a thickness of the layers and obtain the equations with

Various types of machinery are not a continuous whole, but are assembled from various parts according to specific requirements. The surfaces that contact each other between different parts are often called mechanical joints. The stress/displacement field of the mechanical joint structure is the basis for predicting the mechanical properties of the assembly, optimizing the structure and the assembly

In this paper, one of the variants of the smoothed finite element method, α-FEM is adopted for hyperelastic material with large deformation and contact nonlinearity in two dimensions. The salient feature of the α-FEM is that it is stable and this is accomplished by using the scale factor α∈[0,1] to combine the compatible finite element method and the node-based smoothed finite element method. The framework

The Vlasov equation describes the temporal evolution of the distribution function of particles in a collisionless plasma and, if magnetic fields are negligible, the mean electric field is prescribed by Poisson equation. Eulerian numerical methods discretize and directly solve the Vlasov equation on a mesh in phase space and can provide high accuracy with low numerical noise. In this paper, we present

Recently, wavelet theory has become a well recognized promising tool in science and engineering field; especially, wavelets are successfully used in fast algorithms for easy execution. In this paper, we developed wavelet lifting scheme using orthogonal and biorthogonal wavelets for the numerical solution of dynamic Reynolds equation for micropolar fluid lubrication. The numerical results gained through

The main objective of this research is to propose a multidisciplinary approach for the development and design of Computer Numerical Control (CNC) machine tools using numerical optimization methods combined Multi-Body Dynamic (MBD) analysis and to control design co-simulation. Metamodels based Sequential Approximate Optimization (SAO) for the co-simulation optimization problems are developed. The metamodels

Support vector regression (SVR) has been widely used to reduce the high computational cost of computer simulation. SVR assumes the input parameters have equal sample sizes, but unequal sample sizes are often encountered in engineering practices. To solve this issue, a new prediction approach based on SVR, namely as high-low level SVR approach (HL-SVR) is proposed for data modeling of input parameters

Crack initiation and propagation are the two key issues of concern in the geotechnical engineering. In this study, the numerical manifold method (NMM) is applied to simulate crack propagation and the topology update of the NMM for multiple crack propagation is studied. The crack-tip asymptotic interpolation function is incorporated into the NMM to increase the accuracy of the crack-tip stress field

An important technological problem is solved by numerical methods. Doping of silicene with phosphorus allows changing the morphology of the walls of the silicene channel without reducing their strength. The structure of lithium packings in the channels is studied in detail. The distribution of normal stresses in the walls of the channel before lithium intercalation and after complete lithium filling

In this paper, we give some refinements of Simpson’s rule in cases when it is not applicable in its classical form i.e., when the target function is not four times differentiable on a given interval. Some sharp two-sided inequalities for an extended form of Simpson’s rule are also proven.

One of the most important tasks in the numerical analysis of the fracture problem is to achieve a high-precision approximation of the singular stress fields at crack tips. Partially or fully enriched basis functions are often used as enhancements on the whole problem domain or just near the crack tips when constructing the meshless shape functions to simulate the singularity fields at crack tips, namely:

In this paper, we present novel cell-centered finite element methods for the convection-dominated convection–diffusion problems on the general meshes. The proposed schemes can be constructed from a general mesh by building with a dual mesh and its triangular sub-mesh. Moreover, the schemes are based on piecewise linear functions combined with two upwind techniques on the dual sub-mesh in order to stabilize

In this paper, a new family of composite implicit time schemes is developed to overcome some shortcomings of the existing composite schemes. In the development, unconventional time approximations are used for the displacement and velocity vectors. The algorithmic parameters of the approximations are optimized to have improved numerical characteristics. This study also explains some difficulties of

In this paper, we propose the two-level defect-correction stabilized finite element method based on pressure projection for solving the incompressible Navier–Stokes equations. The new method combines the two-level method and the defect-correction strategy with the stabilized method based on pressure projection. It has the good properties of these three methods, such as high efficiency, good stability

Numerical solutions to heat conduction problems involving phase change have traditionally been obtained using the grid-based finite difference or finite element methods. However, due to the unique mathematical form of the equations and the limitations of the grid algorithm, difficulties may arise in solutions. In this study, smooth particle hydrodynamics (SPH) method is used to calculate heat conduction

During the service period of ancient building structures, due to the cumulative development of local damage to load-bearing members such as columns, the structural strength and stiffness will decrease, which may lead to catastrophic accidents. The traditional damage recognition method based on modal parameters is sometimes not effective. In this study, the vibration analysis combined with the relative

In this paper, the dynamic response of piezoelectric structures under hygrothermal environment is studied by using cell-based smoothed finite element method (CS-FEM). Ignoring the influence of temperature and moisture on the response of elastic matrix, we derive the basic equations of the piezoelectric materials under hygrothermal environment. Then the CS-FEM equations of piezoelectric problem are

This paper presents a cell-based smoothed finite element method (CS-FEM) for solving two-dimensional contact problems with the bi-potential formulation. The contact force and the relative displacements on the contact surface are coupled with each other. The Uzawa algorithm, which is a local iterative technique, is used to solve the contact force. The classic Coulomb friction rule and a unilateral contact

Commonly, variance-based global sensitivity analysis methods are popular and applicable to quantify the impact of a set of input variables on output response. However, for many engineering practical problems, the output response is not single but multiple, which makes some traditional sensitivity analysis methods difficult or unsuitable. Therefore, a novel global sensitivity analysis method is presented

The current level of numerical methods of gas dynamics makes it possible to optimize compressors using 3D CFD models. However, the methods and means are not sufficiently developed for their wide application. This paper describes a new method for the optimization of multistage axial compressors based on 3D CFD modeling and summarizes the experience of its application. The developed method is a complex

A novel evaluation study of the most appropriate round function for nearest neighbor image interpolation is presented. Evaluated rounding functions are selected among the five rounding rules defined by the Institute of Electrical and Electronics Engineers IEEE 754-2008 standard. Both full- and no-reference image quality assessment metrics are used to evaluate the influence of rounding functions on

In this work, a face-based smoothed point interpolation method (FS-PIM) is formulated for three-dimensional (3D) thermal elastic-plastic analysis of structures. For this method, field functions are approximated using second order PIM shape functions and the face-based smoothing domains are used to perform the numerical integration. The material properties are considered to be temperature-dependent

The scaled boundary finite element method (SBFEM) has obvious advantages in simulating both finite and infinite domains. However, the present high-order transmission boundary of SBFEM has a problem in numerical stability, especially for 3D fluid–structure interaction (FSI) problems. In this paper, a modified method is put forward to improve the numerical stability of the high-order transmission boundary

The improved reflectance prediction model for printing dot was established with the Monte Carlo method. Reflectance model is a useful approach to predict and control printing quality, which was widely used in color duplication field. The Monte Carlo prediction model for printing dot is a simulation model, satisfying industrial virtual reality needs, which could simulate reflectance data as well as

An iterative domain decomposition method is proposed for numerical analysis of 3-dimensional (3D) linear magnetostatic problems taking the magnetic vector potential as an unknown function. The iterative domain decomposition method is combined with the preconditioned conjugate gradient (PCG) procedure and the hierarchical domain decomposition method (HDDM) which is adopted in parallel computing. Our

In this paper, a cell-based smoothed finite element method using the arbitrary n-sided polygonal element (CS-FEM-Poly) is developed to solve fluid mechanics problems. A stabilization method, characteristic-based split coupled with stabilized pressure gradient projection (CBS/SPGP), is employed to deal with numerical oscillations for CS-FEM-Poly. We validate CS-FEM-Poly and test its numerical behaviors

Lagrangian particle-based methods have opened new perspectives for the investigation of complex problems with large free-surface deformation. Some well-known particle-based methods adopted to solve non-linear hydrodynamics problems are the smoothed parti- cle hydrodynamics (SPH) and the moving particle semi-implicit (MPS). Both methods model the continuum by a system of Lagrangian particles (points)

In order to solve the problem of complex function optimization, the ecological balance dynamics-based optimization (EBDO) algorithm is proposed based on the Lotka–Volterra ecological balance dynamics. The algorithm assumes that there are three populations of nurturers, consumers, and decomposers in an ecosystem. The self-plowing is mainly the plant; the consumer is mainly the animal who feeds on the

A new hybrid fundamental-solution-based finite element method (HFS-FEM) is developed for the transient heat conduction analysis of two-dimensional orthotropic materials. By using coordinate transformation and time-stepping approximation, the governing equation of the original problem is converted to the modified Helmholtz equation. In the solution procedure, the homogeneous solutions of the problem

In this study, the unusual stress fluctuation in the smoothed finite element method (SFEM) for 2D elastoplastic problems is investigated. The governing equation of the 2D elastoplastic problem based on SFEM is presented. The mysterious stress fluctuations from different SFEM approaches are explored. It is demonstrated that conventional finite element method might experience the same symptom. It is

To meet the increasing food demand, production of rice is increased. Unfortunately, rice leaf disease has caused a major problem in the agricultural yield. Various disease prediction strategies are developed in the Internet of Things (IoT) agricultural applications, but accurately predicting the disease causes substantial environmental issues. Therefore, an effective method named Sunflower EarthWorm

This paper sets propelling a more current strategy for mechanical shape optimization by joining a coupled finite element (FE) method–meshfree method (MM) with swarm intelligence (SI)-based stochastic ‘zero-order’ search procedure. The arranged gathering massively fits as a structural shape optimization since MM is utilized here for structural examination shape analysis and to avoid a remeshing in view

The time-fractional problem is a class of important models to represent the real world. It is an open problem to study how the fractional operator acts on the surface. In this work, we present and analyze a meshless local radial point collocation method for numerically solving time-fractional convection-diffusion equations on closed surfaces embedded in ℝ3. The second-order shifted Grünwald scheme

Uncertainties in parameters can affect racing car performance. In this study, a nonlinear interval suspension damping optimization method is proposed to improve the road holding of a racing car. To evaluate the dynamic responses of racing cars under a random road input and a bump input with interval uncertain parameters, a quarter car model with a two-stage asymmetric damper is established. Then, a

This paper presents a constraint handling approach without the need to use a penalty function, namely Optimization Without Penalty (OWP). This approach is used on a recent optimization algorithm based on morphological filters, called Optimization by Morphological Filters (OMF). This work consists of providing a simple and effective constraint-handling approach without the necessity of the penalty for

Accurate models, optimization methods and improvement measures are three key issues in the design and optimization of complex structures in the field of vibration and noise. Due to the increase of passenger vehicle structure complexity and lightweight demand, nonlinear materials and structures increase obviously in the whole system. Not only different structural adhesives are used to strong body structures

There are inherently various uncertainties in practical engineering, and reliability-based design optimization (RBDO) and robust design optimization (RDO) are two well-established methodologies when considering the uncertainties. Naturally, reliability-based robust design optimization (RBRDO) is a methodology developed recently by combining RBDO and RDO, in which the tolerances of random design variables

To accurately simulate the steady-state responses of a functionally graded piezoelectric structure (FGPS) and cure the “overly-stiff” of finite element method (FEM), the coupled thermal-electrical-mechanical inhomogeneous cell-based smoothed finite element method (CICS-FEM) is proposed. The gradient smoothing technique is introduced into FEM and a “close-to-exact” stiffness is obtained. Based on the

Regularization strategies have attracted attention in the structural damage detection (SDD) field. However, there is lack of studies on regularization strategies for damage patterns in the existing methods. This paper proposes regularization strategies for contiguous and noncontiguous damages of structures and performs comparative studies. The objective functions are first defined to consider effects

In this paper, two-dimensional phononic bandgap materials are designed through multiobjective optimization using the genetic algorithm. Two cases are given. In Case I, 2D phononic crystals (PnCs) with maximum bandgap and minimum mass are optimized. The optimal results show that the third-order relative bandgaps become large, along with the increase in mass. In Case II, 2D local resonance phononic crystals

Overlapping multi-domain bivariate spectral quasilinearization method is applied on magnetohydrodynamic mixed convection slip flow over an exponentially decreasing mainstream with convective boundary conditions and nonuniform heat source/sink effects. The method is employed in solving the transformed flow equations. The convergence properties and accuracy of the method are determined. The method gives

In this paper, we report on a strategy for computing the numerical approximate solution for a class of ill-posed operator equations in Hilbert spaces: K:E→F,Kf=g. This approach is a combination of Tikhonov regularization method and the finite rank approximation of K∗K. Finally, numerical results are given to show the effectiveness of this method.

Load identification has long been a difficult issue for distributed load acting on structures. In this paper, the dynamic load identification technology based on the modal coordinate transformation theory is developed for dealing with identification problem of the two-dimensional thin plate structure. For the distributed dynamic load acting on a plate, we decompose it with the mode functions in the

(1) The RAOs of OC4-DeepCWind platform motions are more sensitive to the low-frequency wave than the high-frequency wave. The nonlinear motion responses for platform heave and pitch motions are comparatively remarkable. (2) The pitch motion of OC4-DeepCWind platform is much more apparently influenced by the height of center of gravity (COG) than surge and heave motions. The lower COG height within

The decoupled methods for reliability-based design optimization (RBDO) problems are efficient and accurate. Sequential optimization and reliability analysis (SORA) method and probabilistic feasible region (PFR) approach are typical decoupled methods. When there are multiple constraints in RBDO problem, PFR method improves the efficiency of solving this problem by establishing the PFR to reduce the

The demand for high speed rail networks is rapidly increasing in developing countries like India. One of the major constraints in the design and implementation of high speed train is the braking efficiency with minimum friction losses. Recently, the aerodynamic braking concept has received good attention and it has been incorporated for high speed bullet trains as a testing phase. The braking performance

Understanding seismic energy input and dissipation mechanism is necessary for energy-based seismic design of complex underground structures. Due to the intrinsic uncertainty of ground motion, stochastic methods are usually needed. In this paper, we study the seismic energy input and dissipation mechanism in an underground structure using the probability density evolution method (PDEM). It is found

Viscous flows around ship hull is of great complexity, and when the ship is advancing with drift angles, the flow field can be more complicated. In this paper, the viscous flow field around an obliquely towed surface combatant DTMB 5512 is computed using the unsteady Reynolds-averaged Navier–Stokes (URANS) method. The numerical simulations are carried out by the in-house CFD solver naoe-FOAM-SJTU,

This paper is devoted to the development and quantitative evaluation of the properties of the numerical algorithm of the Cartesian grid method for three-dimensional (3D) simulation of shock-wave propagation in areas of varying shape. The detailed description of the algorithm is presented. The algorithm is relatively simple to implement and does not require solving the problem of determination of the

A numerical model based on the Saint-Venant equations (one-dimensional shallow water equations) is proposed to simulate shallow flows in an open channel with regular and irregular cross-section shapes. The Saint-Venant equations are solved by the finite-volume method based on Godunov-type framework with a modified Harten, Lax, and van Leer (HLL) approximate Riemann solver. Cross-sectional area is replaced

In this paper, an optimized approach is proposed to enhance the performance of combined explicit–implicit time-domain analyses. In this context, an entirely automated explicit-implicit adaptive time-marching procedure is discussed as well as an optimization algorithm is introduced to compute the adopted time-step value of the analysis, so that the amount of explicit and implicit elements occurring

The efficiency of contact search is one of the key factors related to the computational efficiency of three-dimensional sphere discontinuous deformation analysis (3D SDDA). This paper proposes an efficient contact search algorithm, called box search algorithm (BSA), for 3D SDDA. The implementation steps and data structure for BSA are designed, with a case study being conducted to verify its efficiency

This paper presents an efficient numerical technique capable of handling the stress analysis of three-dimensional cracked bodies strengthened by adhesively bonded patches. The proposed technique is implemented within the framework of the coupling of the weakly singular boundary integral equation method and the standard finite element procedure. The former is applied to efficiently treat the elastic

In this work, a novel and robust remeshing algorithm for crack opening problems is proposed, combined with triangular plane stress finite elements. In the proposed algorithm, the crack tip efficiently propagates until a pre-established maximum crack length is achieved and the crack propagation direction is defined considering the maximum tangential stress criterion. The stress state at the crack tip