The selection of points for numerical integration of the Monte Carlo type, largely used in analysis of engineering problems, is developed. It is achieved by modification of the metric in the minimax optimality criterion. The standard minimax criterion ensures the design exhibits good space-filling property and therefore reduces the variance of the estimator of the integral. We, however, show that the

This paper deals with a synthetic presentation of parallel iterative asynchronous algorithms and their extensions for the solution of large sparse linear or pseudo-linear algebraic systems eventually constrained. The behavior of these iterative parallel asynchronous algorithms is studied by three distinct methods : contraction property, partial ordering property linked to the discrete maximum principle

Fabrication efficiency has long been a challenge for additive manufacturing. Standard toolpath generation processes usually give rise to a significant number of non-productive motions that undermine production efficiency and degrade part quality due to frequent acceleration and deceleration in wasted motions. In this paper, we introduce an optimized toolpath generation process that comprises of decomposition

Modeling transient flow conditions in water distribution networks (WDNs) has shown increasing usability for various applications, including burst and leak detection, sensor placement, model calibration, and risk assessment. To facilitate the integration of transient modeling in these simulation-based applications, this work contributes a new open source Python package for Transient Simulations in water

The stiffness and heat dissipation of thin planar structures in industrial engineering are taken as the background for this research. Plant leaves with various vein patterns, such as tobacco (Nicotiana tabacum L.) and chili (Capsicum annuum L.) leaves, are treated as the research objects. Through a combination of morphological and mechanical analysis, the distribution patterns and properties of leaf

In this paper, an efficient explicit topology optimization approach to nearly incompressible materials was proposed. The crucial idea is based on a smooth projection of discrete moving morphable bars (MMBs) onto an analytical grid of polytopal composite finite elements (PCEs). The PCEs, which are built with piecewise linear shape functions and assumed strain fields, aim to mitigate the inherent volumetric

This contribution investigates the influence of anisotropic, linear-elastic material properties resulting from the manufacturing process of long fiber reinforced polymer structures on the stiffness-optimized design of beaded plates. A workflow for the coupling of manufacturing and structural simulations in an automated optimization loop controlled by a genetic algorithm is presented. First, the influence

We present a system for immersive and interactive physics simulation in augmented reality, implemented as an application on the Microsoft HoloLens. The system allows a user to simulate physical phenomena in real-world geometries by scanning the surroundings and automatically creating a finite element discretization (mesh). The system also provides a user interface based on voice commands for specification

Missing time series data in a structural health monitoring system remains a problem in some real-time applications, such as the calculation of cable force. To solve this problem, several algorithms have been proposed to impute missing data. However, studies on extracting temporal correlations from different dimensions to improve imputation have rarely been conducted. In this study, a matrix containing

The shape optimization design of developable surface is a critical and intractable technique in CAD/CAM and used in many manufacturing planning operations. In this paper, we study shape optimization by using a new cuckoo search (CS) algorithm to promote the development of generalized developable H-Bézier surfaces (or GDHBS, for short). According to the duality between points and planes in 3D projective

This paper proposes a novel method for damage detection on a simply supported beam subjected to a moving mass using multiple vibration data measured from a vehicle-bridge interaction (VBI) model. It is shown first that the integral of the difference between the deflection time history of the healthy and damaged beam reaches a local maximum at the location of the crack. As such, the integral of the

The paper investigates strategies for expansion of active set that can be employed by the MPRGP algorithm. The standard MPRGP expansion uses a projected line search in the free gradient direction with a fixed step length. Such a scheme is often too slow to identify the active set, requiring a large number of expansions. We propose to use adaptive step lengths based on the current gradient, which guarantees

Response surface-based simulation optimization method is widely used in the design of complex products for its low-cost in optimization target valuation. However, when design variables increase, it often takes considerable time for high-dimensional response surface to search the optimal point, which falls easily into the local optimum due to the large search space. To solve these problems, a GPU (Graphic

This paper introduces a digital tool to quantify the structural feasibility of single layer assemblages of interlocking blocks. These have corrugated faces to keep the blocks together and prevent them from sliding through the frictional and shear resistances of the locks in two orthogonal directions. Calling the sliding constraint violation of an equilibrated model "sliding infeasibility", it is measured

In this paper, the possible numerical treatments of a new compliance-function-shape-oriented robust truss sizing model with directionally uncertain loads have been analyzed. The applied robustness measure is the total-compliance-variation; the corresponding model is a total-compliance-variation minimization model. The model, according to the number of uncertain loads, can be classified as a curve-length

This paper proposes a highly efficient topology optimization using two accelerated methods, which can reduce the degrees of freedom (DOFs) of the finite element equations and accelerate the iteration convergence of the topology optimization. For the DOF reduction, a method based on the empty elements and the displacement change during the topology iterations is presented to remove the DOFs from the

Loaded tooth contact analysis (LTCA) has always been a significant contact mechanical performance optimization technique for spiral bevel and hypoid gears. To distinguish with the conventional simulated loaded tooth contact analysis (SLTCA) based on economical software package, numerical loaded tooth contact analysis (NLTCA) and its innovative semi-analytical determination approach is developed. In

Curved cable-stayed bridges (CSB) have been increasingly used in the past years. There are currently 42 operational CSB registered in the Structurae database, 37 of which have been built in the last two decades. The minimum cost design of curved S-Shaped pedestrian CSB with external pylons satisfying the static and dynamic code requirements (Eurocodes and Setra guidelines in this work) are found by

Topology optimization of cast parts involving parting surface position is one of the main challenges in engineering design. This work presents a study on topology optimization of cast parts considering various cases of parting surface position. Two casting constraint models for different parting surface position requirements are developed and evaluated. One is a variable parting surface model to achieve

The fibers in concrete is necessary to enhance its engineering properties. Different types of fibers are used as a reinforcing material. Due to low cost, availability, and environmentally friendly, in recent years, the use of natural fibers in concrete has increased attention widely. Among all the natural fibers, jute fibers are very cheap and available in tropical countries. This study assesses different

In this paper, a computational methodology for the band structure analysis of 2D acoustic phononic structures based on the isogeometric boundary element method(IGABEM) is studied. IGABEM not only improves the accuracy of numerical model, but also retains the geometric accuracy and makes the pre-processing procedure relatively simpler for models designed through using computer-aided design(CAD) softwares

In this paper, a stabilized, locally defined, explicit approach is considered to analyse coupled thermo-mechanical models. In this sense, modified central and forward difference methods are adaptively applied following the features of the discretized model; thus, a connected formulation between the adopted temporal and spatial solution procedures takes place. The proposed technique enables stabilized

In this paper, the family of ϕp optimization criteria for space-filling designs is critically reviewed, with a focus on its behavior in moderate to large dimensions, especially for small sample sizes (low saturations of the design domain). Problems that arise during the standard use of the ϕp criteria for the optimization of point sets in standard hypercubic design domains are identified and adequate

Considering the continuous growth of optimization methods and its importance to Emergency Management (EM) systems, this review paper introduces and discusses the recent developments of EM systems after disastrous earthquakes using optimization techniques. Based on a systematic process, we classified a diverse set of selected papers into four main categories: (i) Emergency Response Planning, (ii) Mass

This paper presents an n-th high order perturbation-based stochastic isogeometric Kirchhoff–Love shell method, formulation and implementation for modeling and quantifying geometric (thickness) uncertainty in thin shell structures. Firstly, the Non-Uniform Rational B-Splines (NURBS) is used to describe the geometry and interpolate the variables in a deterministic aspect. Then, the shell structures with

Isogeometric boundary element method is a computer simulation algorithm that can directly utilize the data of a geometric model represented by its surface. Catmull-Clark subdivision surfaces are a widely used technique in 3D computer graphics to construct complicated geometries. In the present work, we combine Catmull-Clark subdivision surfaces with isogeometric boundary element method to simulate

Microservices play a more and more important role in software development nowadays. Almost every programming language has its own microservices development framework. The characteristics of microservices make microservices have cross-platform compatibility issues and inconsistent call standards issues in the process of development and call microservices. The birth of API Gateway alleviates these problems

This paper presents an efficient gradient projection-based method for structural topological optimization problems characterized by a nonlinear objective function which is minimized over a feasible region defined by bilateral bounds and a single linear equality constraint. The specialty of the constraints type, as well as heuristic engineering experiences are exploited to improve the scaling scheme

This article discusses a number of key issues concerning simulation-based digital twins in the domain of multistage processes. Almost all production processes are multistage in nature, and so most digital twins involve multiple physical phenomena, process steps and different solvers for the simulations. Good interoperability between model solvers and processes are key to achieving a functional digital

Toptimiz3D is a graphical user interface for setting up and solving structural topology optimization problems which can handle with general geometries and unstructured meshes. And it is precisely here where the emphasis is placed on. Unlike other existing educational softwares, Toptimiz3D is intended to go a bit further as the aforementioned strengths allow us to face more realistic situations and

Although Cuckoo Search (CS) is a quite new nature-inspired metaheuristic optimization algorithm, it has been extensively used in engineering applications, since it has been proven very efficient in solving complex nonlinear problems. In this paper, efficient modifications have been made to the original CS algorithm to enhance its efficiency and robustness. More specifically, constant parameters of

A roller compacted concrete dam (RCCD) located in Cambodia has been gradually deformed over the operation period (2011–2019), and the creep effect of the dam foundation is significant. In order to make integrity and safety assessments of the dam, it is necessary to know the actual mechanical properties of the foundation. This research proposes an intelligent computational framework for analysing the

Vibration characteristic is one of the most important properties for structures and mechanical systems. Transfer matrix method for linear multibody systems (linear MSTMM) is an efficient approach to computing the vibration characteristics of such systems due to its following features: easy to formulate, high programming, and low-order matrix without system global dynamic equations. In this work, a

In order to provide the rehabilitation training for patients with impaired upper limb motor function, this article proposes an α-variable adaptive model free control (α-AMFC) for a 7-DOF upper limb exoskeleton which is denoted as iReHave and designed based on SolidWorks. The referred α-AMFC is developed based on a time-delay estimation based intelligent PID control (TDE-iPID) and an α online adaptive

The experimental execution, theoretical analysis, structural optimization and performance prediction of lunar rover wheels are subject to many limitations due to the particularity and complexity of the lunar environment. The numerical simulation has notable advantages in analyzing the interaction between wheels and lunar soil simulant and designing the lunar rover wheels applied to complex environments

An integrated geometric design sensitivity (DSA) method for weakly coupled thermoelastic problems is developed in this study using boundary integral equations with an isogeometric approach that directly utilizes a CAD system's NURBS basis functions in response analysis. Thermomechanical coupling frequently creates thermoelastic behaviors in plants and nuclear systems and requires a structural optimization

Tunnelling induced surface settlements can cause damage in buildings located in the vicinity of the tunnel. Currently, surface settlements and associated building damage risks usually are estimated based on empirical equations, e.g. by assuming Gaussian curves for the settlement trough and by applying the Limit Tensile Strain Method or the tilt-based method to evaluate and categorise the expected building

Parallel computing is used to accelerate the computations in the reduction of speckle noise in medical ultrasound images. A new hybrid algorithm for speckle noise reduction in medical ultrasound images is proposed and compared to an existing efficient method. The method combines in an efficient manner the advantages of several denoising filters using local and non-local information. A comparative study

A unified design solution for heterogeneous explicit hyperbolic solvers is herein introduced. The proposed design is entirely cross-compatible between CPUs and GPUs, through an intuitive object-oriented approach. The advantages of a unified CPU+GPU development approach are discussed and exemplified, and a complete description of the data and code structures are provided and benchmarked. The benefits

Moving Morphable Component (MMC) based topology optimization approach is an explicit algorithm since the boundary of the entity explicitly described by its functions. Compared with other pixel or node point-based algorithms, it is optimized through the parameter optimization of a Topological Description Function (TDF). However, the optimized results partly depend on the selection of related parameters

A new semi-analytical approach is described for calculating the potential and electric field in a system of infinitely long parallel cylindrical conductors. The method is based on the dipole simulation technique and the method of successive dipole images. For a system of N conductors with predefined potential differences between them, this method leads to a linear system of n = N(N–1)/2 equations for

The article presents a full three-dimensional (3D) numerical analysis of curved laminated shell structures using only a two-dimensional (2D) planar finite element mesh. The applied numerical method is called FEM23, which stands for the 2D finite element method for a full 3D analysis. FEM23 makes it possible to perform a numerical analysis of a multi-layered shell, utilising a numerical model based

A systematic procedure of high-precision parameterization and multi-objective optimization for airfoils was proposed in this paper in order to improve the aerodynamic performance under full working conditions. The Bezier curve was applied in the airfoil parameterization with the coordinates of the 8 Bezier control points chosen to be the design variables. The control points were initialized by self-programming

This literature survey concerns the application of optimization techniques to cable-stayed bridges. A search within the Web of Science and Scopus electronic databases was conducted, complemented by a hand search. From a total of 155 articles, 90 were chosen for a detailed review. The search results are summarized, highlighting the procedures, the main conclusions and contributions of each work. The

In this work, an edge-based smoothed finite element method (ES-FEM) is embedded into the commercial software ABAQUS by using user defined element subroutines (Implicit/UEL, Explicit/VUEL). Unstructured meshes (i.e. triangular and tetrahedral elements) are employed in the framework due to their good geometric adaptability and the advantages of being automatically generated in the software. In ES-FEM

This paper proposes a methodology for the topology optimization of continuum structures subject to dynamic stress response constraints under stochastic loads. The topology optimization model is built, where the objective function is the structural weight, and the dynamic stress constraints are applied. In order to greatly reduce the computational cost of dynamic stress responses and prevent stress

We present a Bernstein–Bézier finite element method with local mesh refinement to simulate the heat transfer problem in the welding process. A novel constraint method is formulated to handle the incompatible degrees of freedom associated with the transitional elements during the local quad-tree/oct-tree refinement. A dynamic refinement strategy is proposed with a local L2 projection approach to transfer

Development in large-scale geotechnical engineering simulation places tremendous demand for efficient visualization of such simulation data. This study presents a lightweight software tool, i.e. Geotechnical Interactive Visualization (GIV), as a solution to this challenge, which achieves efficient interactive visualization of large-scale simulations data in geotechnical engineering. Visualization data

In this paper, a parallel computing scheme for performing implicit finite element calculations on acoustic problems running on a graphics processing unit (GPU) is proposed. This scheme combines the element-by-element (EBE) strategy and the edge-based smoothed finite element method (ES-FEM). A mapping strategy based on the ES-FEM is developed to parallel calculate various formulas for smoothing domains

The structured meshes are widely utilized in the aircraft industry because of their efficiency in achieving accurate solutions, especially for viscous flows of complex configurations. However, they are usually generated by engineers through enormous and tedious interaction with the graphical user interface of mesh generation software. To address this issue, we implement one piece of interactive structured

An open source software package to generate numerical model for finite element method (FEM) and discrete element method (DEM) based on digital image is proposed. Both 2D bitmap and 3D volumetric images are supported. This package includes geometrical and analytical routines for vectorizing bitmap image, computing geometric information statistics, and generating numerical models. The ability of handling

To accurately simulate the mechanical properties of rockfill materials under triaxial stress using the discrete element method (DEM), the microparameters of the rockfill material DEM model are calibrated based on the macroparameters of a constitutive model. For the calibration model, a refined 3-D numerical triaxial test is established to obtain the deformation curves of the rockfill under different

Compared with arithmetic operation, communication cost is often the bottleneck on modern computers, and thus should be paid increasing attention when choosing algorithms. Lagged gradient methods are known for their error tolerance and fast convergence. However, it appears that their parallel behavior is not well understood. In this paper, we explore the cyclic formulations of lagged gradient methods

This paper provides the description of a novel, multi-purpose spline library. In accordance with the increasingly diverse modes of usage of splines, it is multi-purpose in the sense that it supports geometry representation, finite element analysis, and optimization. The library features reading and writing for various file formats and a wide range of spline manipulation algorithms. Further, a new efficient

Proper functioning and safety of anchor elements are decisive for the overall performance of a structural system. A possible failure mode for anchor loaded in shear is the concrete breakout failure. Concrete related failure mode poses a significant safety issue, since they may develop abruptly/brittle, without preceding signs of damage. Consequently, accurate prediction of the concrete breakout strength

This paper presents a novel method for the optimization of the dynamic behavior of a laminated cylinder through stacking sequence optimization. The number of layers reaches 48 and the optimized parameters are either the value of the fundamental natural frequency or the width of the frequency gaps around the excitation force frequencies. The proposed procedure involves automatic mode shape identification

In order to obtain reliable operating conditions, uncertainties must be taken into account in the mathematical modeling of systems and processes. An uncertainty is measured by the probability of failure of the process, which can be tackled by inverse reliability analysis. This analysis guarantees the achievement of the probabilistic constraints at a specified level. Here, we propose a new methodology

In this study, an efficient method is proposed for the safety evaluation of steel trusses using the gradient tree boosting (GTB) algorithm, one of the most powerful techniques in machine learning (ML). Datasets are first generated using the advanced analysis to consider both geometric and material nonlinearities of the structure. Four GTB models are then proposed to predict the ultimate load-carrying