In this paper a new approach to handle stress-based topology optimization problems by using the Topology Optimization of Binary Structures method is presented. The design update is carried out with binary values (0 or 1) and a boundary identification scheme is employed to smooth the structural contours to avoid artificial stress concentrations that can occur because of the jagged nature of the topology

This paper is interested in developing reduced order models (ROMs) for repeated simulation of fractional elliptic partial differential equations (PDEs) for multiple values of the parameters (e.g., diffusion coefficients or fractional exponent) governing these models. These problems arise in many applications including simulating Gaussian processes, geophysical electromagnetics. The approach uses the

Rotating electrical machines are becoming ubiquitous as we move towards a more electrified and sustainable world. Torque calculation is an essential task in the design process of rotating machines. In the frame of finite element analysis, the Maxwell stress tensor method is a common technique to calculate the torque exerted on a rigid body. However, the computed torque is strongly mesh-dependent and

In order to ensure the reliability of a numerical simulation software, verification and validation are unavoidable tasks. In this paper, we present a new rigorous code verification strategy based on manufactured solutions for the static analysis of geometrically non-linear Kirchhoff–Love shells and apply it to Isogeometric Analysis (IGA). While IGA is based on a parametric surface description, we advocate

In very thin ply laminates, delamination failure initiation occurs at much higher stress levels as compared to conventional ply laminates. This results in significant plastic deformation in the matrix accompanied by large fiber rotations. A closer look reveals that microstructure of fiber reinforced composites at large strains do not rotate with the plastic spin induced by the total deformation gradient

In the context of MOR techniques for parametrized PDEs, a novel computational method relying on NURBS-based geometric mappings and PGD-based space separated representations has recently been developed. Such approach has opened new perspectives to classical PGD formulations. In particular, it has extended the use of the PGD to complex non-separable an non-simply-connected domains. Moreover, the domain

We propose a new Ritz vector-based dynamic substructuring method which substitutes the unit pseudo-forces applied at the adjacent degrees of freedom (DOFs) using distributed forces. One of the main problems of the Ritz vector and unit pseudo-force-based dynamic substructuring method is the strong dependence of the number of reduction bases on the interface DOF, which is not reduced by substructuring

In this paper, a novel strategy based on nonlinear thermal analysis has been developed using finite element simulations and artificial neural networks in order to predict the time-temperature distributions in arc welding process. The highly nonlinear and transient thermal finite element methodology pertaining to simulations of arc welding process is investigated through various combinations of numerical

In this paper, we propose a novel ROM stabilization strategy for under-resolved convection-dominated flows, the approximate deconvolution Leray ROM (ADL-ROM). The new ADL-ROM introduces AD as a new means to increase the accuracy of the classical Leray ROM (L-ROM) without degrading its numerical stability. We also introduce two new AD ROM strategies: the Tikhonov and van Cittert methods. Our numerical

This study introduces a novel topology optimization method for transient two-phase fluid problem with continuous behavior, which remains a challenging task despite advances in computing capabilities. The application of gradient-based optimizer to continuous two-phase fluid systems is complicated because it requires some modifications of the governing equations to reflect changes in the interface between

Numerical modelling of geogrids is a challenging task, with extruded geogrids often presenting complex geometries and nonlinear tensile response even at low strain rates. In this study, three-dimensional (3D) models were developed in ABAQUS to investigate the in-isolation tensile response of extruded geogrids, accounting for a detailed geometric discretization. Hyperbolic constitutive models were used

The Finite Element Updating Method (FEMU) is routinely used to determine material model parameters that cannot be directly measured. Literature has identified that the inverse process results in local minima yielding solutions that are non-unique for a given load case when determining the parameters of a Mooney Rivlin material model. This non-uniqueness results in multiple sets of parameters for a

This work is devoted to developing an efficient and robust technique for accurately capturing the electric field in multi-material problems. The formulation is based on the finite element method enriched by the introduction of hat-type shape function within the elements crossed by the material interface. The peculiar feature of the proposed method consists of direct employment of the hat-function that

In this study, we investigate the feasibility of using a vibration-based metric for predicting low-frequency structure-borne noise in cross-laminated timber (CLT) buildings. The overall aim here is to facilitate the conceptual design for CLT buildings in terms of estimating noise levels. Since noise levels are inherently sensitive to architectural or mechanical design changes, in the low frequency

Abstract not available

A phase-field approach was used in order to model the complex mechanisms of fatigue crack nucleation and growth. This popular method enables a flexible framework that recovers accurately expected crack patterns. However, it usually suffers from several efficiency drawbacks, such as the need for a very fine mesh, and the heavy computational cost associated with the cycle by cycle approach. For this

A novel Adaptive Formulation Refinement (AFR) strategy for Friction Stir Welding (FSW) problems is presented. In FSW, the accurate computation of strains is crucial to correctly predict the highly non-linear material behavior in the stir zone. Based on a posteriori error estimation, AFR switches between two mixed formulations depending on the required accuracy in the different regions of the domain

The calculation of stress intensities used when processing growth data from fatigue tests on corner crack test pieces typically uses geometry correction factor polynomials derived from 3D finite element (FE) analyses with a remote applied load but no controls on nodal displacements. The built-in threaded ends of the test pieces, however, impose a constraint that results in significantly lower correction

This study investigates the application of formulations employed by standard Bubnov-Galerkin Finite Elements to alleviate volumetric locking in the context of the Absolute Nodal Coordinate Formulation (ANCF). Volumetric locking is a prevalent phenomenon that occurs when linearly interpolated displacement fields are used to model incompressible phenomena. Although linear interpolations for the displacement

This paper investigates the performance of an integrated control system based on the acoustic black hole effect and piezoelectric actuators for structural vibration suppression in beams. The acoustic black hole is a technique for passive vibration control consisting of a power-law tapered profile built on structures. Its effect takes place in the acoustic black hole termination, where the velocity

Thermal shocks are ubiquitous in engineering applications. Due to the multi-field nature, numerical simulation of thermally induced cracking and subsequent propagation is challenging. Thanks to the recent introduction of variational phase-field model of fracture, it is now possible to numerically model the complex behavior of damage nucleation, growth, bifurcation and coalescence within one unified

The slightest parametric modification could strongly affect the dynamic behavior of mechanical structures. The challenge is to develop numerical models that could be adaptable to the occurrence of modifications without neither significant loss of accuracy, nor significant computational time consuming, compared to high-fidelity models. The present paper proposes a model order reduction procedure which

To create a human-like skin for a robotic application, current touch sensor technologies have a few drawbacks. Electrical Impedance Tomography (EIT) is a candidate for this application due to its applicability over complex geometries; nevertheless, it has accuracy concerns. This study employs artificial neural networks (ANNs) to investigate the accuracy and capability of EIT-based touch sensors. A

Free-form surface structures are extensively utilized in practical engineering due to their rich architectural expression and strong visual impact. However, ensuring good mechanical behavior during the generation process of free-form surface structures has become a critical problem in the scientific community. Isogeometric analysis (IGA) is a widely adopted approach in various fields owing to its numerous

The design and manufacturing of high value industrial components is suffering a change of paradigm with 3D printing, where a macro–micro structural optimization of architected metamaterials is pursued to endow the material and the component of customized mechanical properties. Topology optimization techniques facilitate the design of both the microstructures and the overall component topology. However

The Proper Generalized Decomposition has shown its efficiency to solve parameterized problems in nonlinear system events when it is combined with the Discrete Empirical Interpolation Method. Nevertheless, the solution of finite element model with the Proper Generalized Decomposition framework requires to have access to matrices and vectors of the discretized problem, which makes the method highly intrusive

A modeling method combining finite element and lumped parameter (FE-LP) model is proposed for accurately simulating loudspeaker systems with flexible enclosures, such as speakerphones, AI speakers, and portable Bluetooth speakers. In this approach, the mechanical components of the driver unit, except for the cone assembly (consisting of the dust cap, cone, and surround), are represented by lumped parameters

The study of molten pool characteristics is a powerful means of determining the quality of laser additive manufacturing forming. In this paper, a three-dimensional transient thermal flow field numerical model of Ti6Al4V powder processed by LPBF is developed based on FLOW-3D software, and the dynamic evolution of the molten pool with fixed process parameters is quantitatively described using dimensionless

The current study proposes a shot peening model which enables the residual stress interaction with grinding, a typical combination for gear finishing. The effect of the interaction on the stress state development was addressed by comparing the residual stress state from a standalone shot peening procedure, against the residual stress state arising from a manufacturing route where the interaction of

Abstract not available

Coupled multi-scale finite element analyses have gained traction over the last years due to the increasing available computational resources. Nevertheless, in the pursuit of accurate results within a reasonable time frame, replacing these high-fidelity micromechanical simulations with reduced-order data-driven models has been explored recently by the modelling community. In this work, two classes of

This paper presents an improved non-sensitivity structural topology optimization method incorporating virtual elements with unstructured polygonal meshes. Specifically, we employ the recently developed gradient-free proportional topology optimization (PTO) approach, for the first time, together with a new material distribution formula suitable for both minimum compliance and compliant mechanism problems

Herein we present a prediction method for the process-induced distortion (PID) of a 2-D triaxially braided composite (TBC) structure at the macroscopic level based on a simplified constitutive model and analytical model for the effective material properties (EMPs). This method can quickly predict the PID considering viscoelastic characteristics and different geometric parameters of the 2-D TBC. The

In this paper, the edge effect of a parallel plate capacitor is numerically analyzed using the extended finite element method, which exhibits higher accuracy than the standard finite element method. The enrichment function, which plays an important role in this method, is numerically computed on the virtual plane in a simple manner using conformal mapping and complex number techniques. The complex

Due to its various advantages, welding is commonly used in the construction for steel connection. However, the local temperature difference in the welding causes welding deformation and residual stress. The welding deformation and residual stress can significantly impact the load-bearing performance of members. Therefore, it is important to evaluate those behaviors with high precision. In the previous

Finite-element analysis is the only means to determine the load situation of slewing bearings with complex interfaces. For reliable results, the finite-element model needs to be validated by comparing the simulation results against measurement results. Most published finite-element bearing models of slewing bearings are not validated at all, and none of the publications investigate the accuracy of

Abstract not available

Spalling is a typical damage mode of reinforced concrete (RC) structures subjected to blast and impact loads. Concrete debris from spalling damage could be ejected with high velocities therefore impose significant threats to surrounding structures and people. Current numerical methods such as finite element method (FEM) based on continuum damage mechanics have inherent limitations in predicting fragmentation

The earthquake response of bridge cranes is a very important safety issue for industrial facilities, for example, nuclear plants. During an earthquake, the bridge crane is subjected to multi-impacts and frictional contacts between trolley wheels and girder rails, as well as between crane wheels and runway rails. In this paper, an efficient explicit/implicit transient analysis with Rayleigh damping

This work introduces “generalized meshes”, a type of meshes suited for the discretization of partial differential equations in non-regular geometries. Generalized meshes extend regular simplicial meshes by allowing for overlapping elements and more flexible adjacency relations. They can have several distinct “generalized” vertices (or edges, faces) that occupy the same geometric position. These generalized

This study presents a novel method for the structural design of thermal conductors using functionally graded materials (FGMs). The effective thermal conductivity tensor components of the unit structure of the FGM composite were obtained using the representative volume element (RVE) homogenization method under periodic boundary conditions. In addition, a machine learning method of neural network fitting

The cause of the standing wave in radial passenger car tires is investigated using the dynamic transient finite element analysis to predict a steady free-rolling state under high-speed conditions. First, the approach is validated by high-speed durability test results on two different tires. The critical speed of the standing wave and the position of the wave according to speed are qualitatively compared

This paper presents the formulation of strain-based finite elements for modelling composite beams with finger joints considering slip between the layers. The finite elements are derived according to Reissner beam theory based on the modified principle of virtual work where the displacements and rotations are eliminated from the problem and the axial deformation, shear deformation and curvature of the

Abstract not available

Mechanical or geometrical interlock between steel bars and concrete directly affects the bond strength in reinforced concrete structures. This aspect is usually neglected, or at least indirectly considered, when modelling and simulating reinforced concrete structures using macroscopic models, due to the difficulty and complexity it adds to such structural simulations on large structures. However, modelling

The Finite Element Method (FEM) suffers from important drawbacks in problems involving excessive deformation of elements despite being universally applied to a wide range of engineering applications. While dynamic remeshing is often offered as the ideal solution, its computational cost, numerical noise and mathematical limitations in complex geometries are impeding its widespread use. Meshless methods

Calculating the dynamic response of equipment mounted on submarine hulls to the underwater explosions require handling a “coupled” model, composed of the equipment and the hull immersed in a fluid in order to represent the physic involved, namely fluid/structure interactions and mechanical interactions between the equipment and the hull. For various industrial applications, it is necessary to describe

The ball burnishing process is a simple, fast, and cost-effective surface finishing process applied to improve the surface integrity of manufactured industrial components. The numerical simulation of this mechanical finishing process is growing interest in the research and industry due to improving the understanding of the surface treatment, analyzing and predicting the effect of the ball burnishing

A novel implementation of the traditional node-to-node Coulomb contact-friction problem is presented that utilizes run-time parameter updates on conventional elasto-plastic elements. The two-noded elements are defined by an independent uniaxial force–deformation (or constitutive) relation in each degree of freedom. The location of the two nodes may or may not be coincident. A parameter is a pointer

Abstract not available

Polycrystalline solids are composed of many small grains of varying sizes and crystallographic orientations. An elastic wave that propagates through such a material experiences distortion and attenuation. While the influence on propagation in random configurations can be captured with conventional statistical descriptors, the role of second-order features such as the hierarchical gradient in material

In this study, we propose a novel deep learning model named as the Finite-element-informed neural network (FEI-NN), inspired from finite element method (FEM) for parametric simulation of static problems in structural mechanics. The approach trains neural networks in the supervised manner, in which parametric variables of structures are considered as input features of network and spatial ones are implicitly

The theories for thick plates and beams, namely Reissner–Mindlin’s and Timoshenko’s theories, are well known to suffer numerical locking when approximated using the standard Galerkin finite element method for small thicknesses. This occurs when the same interpolations are used for displacement and rotations, reason for which stabilization becomes necessary. To overcome this problem, a Variational Multiscale

Composite materials inherently own desirable properties including high strength, high stiffness and good toughness. The macroscopic mechanical properties of composite materials are generally anisotropic. Fracture in anisotropic or orthotropic materials has been widely concerned by researchers in the fields of computational mechanics, aviation, aerospace, construction, etc. The phase-field method (PFM)

Abstract not available

A proper orthogonal decomposition with RBF interpolation (PODI-RBF) method has been developed to solve indenter contact problems in real time [1]. In the PODI-RBF method, POD basis vectors extracted from global solution snapshots, which are obtained from full-order simulations of indenter contact problems with a set of training contact locations, may not accurately represent local deformations near