This paper proposes a modified version of a contemporary metaheuristic named Harris Hawks Optimizer (HHO) that mimics the foraging strategies used by Harris hawks. It is first argued that exploration ability of HHO is weaker than its exploitation. In addition, the initial position of hawks has the greatest impact on the convergence of the solutions in a similar manner to other metaheuristic algorithms

Microscopic traffic simulation (MTS) is the emulation of real-world traffic movements in a virtual world with various traffic entities (e.g., vehicles and pedestrians). Typically, the movements of these entities in the simulation are governed by some pre-defined algorithms (e.g., car-following models and lane-changing models). Modelers may develop customized algorithms through an application programming

With the rapid development of high-speed and urban rail transit, ballastless slab tracks have been widely used in many areas. The work on construction, design, and mechanics of ballastless slab tracks is abundant and achievements have been made. However, a platform for numerical simulation and dynamic analysis of slab track systems subjected to a moving train still needs to be probed into. In the MATLAB®

The ongoing increase in computational capabilities has been successfully utilized for the engineering task of determining an optimal structural design, allowing for high-fidelity simulations of possible design parameter combinations. However, the more detailed these simulation models are, the more expensive a single performance prediction becomes, making the determination of the optimal design a very

This paper proposes an effective density correction method to improve the accuracy and reliability of smoothed particle hydrodynamics (SPH) simulations. The density field calculated in the SPH procedure is automatically corrected by a new density interpolation adopting shape functions, which is individually applied to each particle. The proposed method makes the density field smoother, effectively

Masonry infill is usually neglected in the design and it is treated as a non-structural element instead of its stiffness and lateral resistance capacity. Their presence in the RC frame could also affect the lateral load resistance. The interaction of infill presence in the RC frame will also depend on the aspect ratio of frame and openings presence in the infill. The infill collapse initiated disaster

ISO 10303 STEP AP209 edition 2 ISO (1994), ISO (2014a)[1,2] is a data model standard intended for data exchange and storage of simulation information. The standard has a wide coverage of FEA (Finite Element Analysis) information, but is missing certain features such as nonlinear FEA. This paper gives an introduction to the STEP AP209 standard and presents projects in which AP209 has been implemented

Low-level object matching can be done using projection signatures. In case of a large number of projections, the matching algorithm has to deal with less significant slices. A trivial approach would be to do statistical analysis or apply machine learning to determine the significant features. To take adjacent values of the projection matrices into account, a convolutional neural network should be used

This paper presents an object-oriented optimization framework for engineering optimization using the Matlab programming syntax. The novelty of the developed framework lies in its approach to remove redundancies by providing an interface for central routines of the optimization processes. Object-oriented programming is used to implement an abstract optimizer class, which controls the optimization process

This paper proposes a novel weighted graph representation for structural topology optimization. Based on the graph theory, a weighted adjacency matrix is first introduced to collect the connectivity information and the corresponding width value of the edges. Accordingly, each edge with different width is symbolized as a rectangle to represent the mapped topology for a regular meshed design domain.

Identifying the hotspots for damage initiation in large-scale composite structure designs presents a significant challenge due to the high modelling cost. For most industrial applications, the finite element (FE) models are often coarsely meshed with shell elements and used to predict the global stiffness and internal loads. Because of the lack of detailed descriptions for the composite materials and

The paper improves a preliminary experimental study on a cluster by adding both theoretical results and experimental tests on a grid platform. These algorithms solve univalued and multivalued pseudo-linear problems using parallel asynchronous multisplitting methods combined with Krylov’s methods. This paper also analyses these algorithms using contraction techniques. Two distinct applications, with

This paper presents and discusses a hybrid-mixed stress (HMS) finite element model for the static and dynamic analysis of 2D reinforced concrete frame structures. It is assumed a physically non-linear behaviour for both concrete and steel. In this model, both the stress and the displacement fields are approximated in the domain of each element. Complete sets of orthonormal Legendre polynomials are

Cluster analysis is a valuable data analysis and data mining technique. Nature-inspired population-based metaheuristics are promising search methods for solving optimization problems including data clustering. In this paper, a recently proposed algorithm called the water cycle algorithm, based on the evaporation rate is used in conjunction with a local search method namely Hookes and Jeeves method

In recent years, the analysis of the community response in case of disastrous events has become a research topic of paramount relevance due to the increasing number of calamities like flooding, hurricanes, and earthquakes. In particular, the possibility to use computer simulations to model and study the behavior of thousands of people during an emergency evacuation can provide valuable information

Environmental assessment is a critical activity for ensuring buildings are performing according to specified requirements, and efficient, seamless exchange of building information is crucial for environmental assessment. Therefore, all those involved in built environment issues should be able to access and share not only building information but also data about products, especially environmental assessment

This paper presents a novel combination of Generative Adversarial Networks (GANs) and Clustering Analysis (CA) for topology optimization. Based on the results from the topology analysis, new data are generated by the GANs and Deep Convolutional GANs (DCGANs). K-means Clustering Analysis is employed to select optimized valid data with the minimum compliance and the discreteness of design variables out

Present metamodel based global optimization algorithms usually build an evolving metamodel using initial and updated sample points to speed up the search of the global optimum. In this research, we proposed an efficient and robust multiple meta-model-based global optimization method (EMMGO). The EMMGO starts with two different sets of initial points and two different sets of evolving metamodels to

Hollow structures can meet the demand of thickness control in manufacture, and achieve lightweight structures in design. However, topologically optimized results are generally solid structures, which are not easily transformed into hollow structures. Therefore, this paper proposes a three-dimensional moving morphable bar method to obtain hollow structures directly. The geometrical features of the three-dimensional

This article introduces two strategies to reduce the memory cost of the Adaptive Multipreconditioned FETI method (AMPFETI) while preserving its capability to solve ill conditioned systems efficiently. Their common principle is to gather search directions into aggregates which are frequently adapted in order to achieve the best compromise between the decrease of the solver error and the computational

Modal superposition (MS) techniques are widely used in linear dynamic analyses but the study of large structures subject to actions such as long vehicle convoys is not currently feasible. This work presents an algorithm called MS5 embedded in the Python library MDyn that combines an efficient indexing strategy to deactivate specific structural nodes and movements with a novel modal truncation based

The traditional element-based topology optimization based on material penalization typically aims at a 0/1 design. Our numerical experiments reveal that the compliance of a smooth design is overestimated when material properties of boundary intermediate elements under the fixed-mesh finite element analysis are interpolated with a material penalization model. This paper proposes a floating projection

In this paper a parallel implementation strategy is presented, for meshless methods, using principles of functional programming and memory polymorphism. The meta-programming presented technique has been developed to guarantee portability of performance in different execution spaces and simplified representation of the mathematical physics model through simple use of declarative programming. To this

This paper presents an integrated approach that combines advanced survey procedures, such as close range photogrammetry based on high resolution images provided by Unmanned Aerial Vehicles, and Ambient Vibration Tests to develop accurate Finite Element models of severely damaged historic masonry structures. The proposed methodology is applied to a masonry arch bridge located in Todi, Central Italy

GPU-based parallel algorithms for large-scale DEM simulations of spherical elements have been well established. However, complex systems composed of non-spherical elements are common in nature and industry. The dynamic behavior and mechanical properties of non-spherical elements are significantly different from those of spheres on the macroscopic and microscopic scales. Considering the construction

The demand for advanced manufacturing is gradually turning to the multi-functional integrated structure, so the effective and innovative functional structure topology optimization design method can maximize the performance of the structure. This paper proposes a parallel topology optimization design method for dynamic and static characteristics of multiphase materials. The inherent discrete design

Quantum Computing is becoming an increasingly mature area, with a simultaneous escalation of investment in many sectors. Quantum technology will revolutionize all the engineering fields. For example, companies will need to add quantum computing progressively to some or all of their daily operations. It is clear that all existing classical information systems cannot be done away with. Rather than that

Train operations generate high impact and fatigue loads that degrade the rail infrastructure and the vehicle components. Rail pads are installed between the rails and the sleepers in order to damp the transmission of vibrations and noise and to provide flexibility to the track. These components play a crucial role in maximizing the durability of the railway assets and minimizing maintenance costs.

A majority of physical models are written as partial differential equations. For most of these equations, analytical solutions cannot be obtained and they can be solved only numerically using e.g. the finite element method. To not waste time programming, it is vital for researchers working on state-of-the-art numerical methods to adopt a flexible, efficient, open source and research-oriented library

An automatic full 3D mesh generator for the non-linear 3D homogenized discrete FE analysis of masonry double curvature structures is presented. The method can reproduce the main features exhibited by masonry, preserving the orthotropy and accounting for the influence of membrane loads on the flexural behavior. Previous homogenization procedures allow reducing the number of variables, leading to non-linear

Time series analysis and novelty detection are effective and promising methods for data-driven structural health monitoring (SHM) based on the statistical pattern recognition paradigm. However, processing substantially large volumes of vibration measurements may represent a serious limitation, especially for long-term SHM programs of large-scale civil structures. Moreover, shortcomings like the choice

In this study, a DisContinuous IsoGeometric Reanalysis (DCIGR) method is proposed to analyze and optimize the model of Non-Uniform Rational B-Splines (NURBS) patches with non-matching interfaces. In the DCIGR, the Nitsche method is adapted to couple NURBS patches with gaps and the smooth algorithm is developed to correct singular stresses resulting from gaps. However, the additional stiffness matrices

This paper proposes a new methodology for continuum topology optimization that is capable of fatigue-resistance design. Firstly, penalized stress is adopted to circumvent the singularity issue. Secondly, another additional penalization formulation of the elemental fatigue damage is proposed. The quasi-static finite element method is performed to calculate structural responses efficiently according

Element-based topology optimization algorithms capable of generating smooth boundaries have drawn serious attention given the significance of accurate boundary information in engineering applications. The basic framework of a new element-based continuum algorithm is proposed in this paper. This algorithm is based on a smooth-edged material distribution strategy that uses solid/void grid points assigned

Simulation techniques when applied for metrological estimations have recently emerged as a tool for potential improvement in design and performance aspects. The current paper reports one such application for the numerical estimation of the distortions and strains developed in a standard piston gauge leading to the estimation of the effective area and the pressure distortion coefficient up to a pressure

Jaya algorithm (JA) is a single-step metaheuristic optimization technique that is free from algorithm-specific parameters. Regardless of its simplicity, JA proved its effective performance against the variety of optimization algorithms (Du et al., 2018). However, like other swarm-based optimization techniques, the JA also suffers from the inadequacies of slow or premature convergence (Farah and Belazi

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