In order to improve the topology optimization results for the requirements such as manufacturability and functionality, and to strengthen the link between structural topology optimization and computational topology, this paper measures the topology and thickness of the structure using topological invariants (i.e., Euler characteristic and Betti numbers) in the computational topology. Based on set theory

Displacement response spectra (DRS) are crucial for seismic design as earthquake damage correlates more with displacements than forces. Previous efforts to develop attenuation relations for DRS have been largely approximate. Permanent displacement or Fling poses significant design, repair and rehabilitation challenges. Consideration of DRS and Fling in seismic design and performance assessment necessitates

The role of dimensionless ratios in engineering and physics is ubiquitous; but their utility in the multiphysics community is sometimes overlooked. Notably, in the multiphysics modelling community, coupling methods are often discussed and developed without an explicit monitoring of the various dimensionless ratios of the various inter-physics coupling terms. However, it is evident that the varying

In this work, a topology optimization algorithm has been developed to design bi-material lattice structures showing a band gap around a target frequency, using just one unit cell through the application of Bloch-Floquet theorem. The Bidirectional Evolutionary Structural optimization (BESO) method has been employed, based on bi-material interpolation. A new objective function has been defined, which

This paper introduces a novel approach for analyzing the frictionless two-dimensional contact between dielectric solids in an electrostatic medium. This analysis is achieved by combining the finite element and boundary element methods. The finite elements model elastic dielectric solids undergoing geometrically nonlinear mechanical deformation and electric polarization. We present a finite element-based

In this study, two state-of-the-art implementations of the rate-dependent Crystal Plasticity Finite Element Method (CPFEM) as user material subroutines in the finite element solvers Abaqus/Explicit and Abaqus/Standard (Implicit) are presented. Adaptive substepping in the explicit solver and line-search stabilized implementation in the implicit solver enable fast and stable calculations also for small

The quadrilateral surface mesh modification method based on dual cycle operations shows promising advantages in hexahedral mesh generation. However, as only simple cycle eliminations are considered, the existing methods can not handle complex surface meshes. In this study, an improved method based on cycle elimination is proposed for high-quality hexahedral mesh generation from a given quadrilateral

This paper introduces a new quadrilateral plate element named DSPM4, which improves upon the previous Q4γs element. The DSPM4 element has twelve DOFs and four temporary DOFs at the mid-sides of the element. The rotation functions βs are modified by adding an incomplete quadratic function to improve the bending performance. An orthogonality condition between the lower and higher-order bending energy

This paper presents a machine learning-based finite element construction method (MLBFE) to predict a precise strain field with minimal nodes. The method first establishes a standardized MLBFE model via the substructure concept and the static condensation method. Then, a training data collection method involving nodal displacements and strain fields, and considering (1) boundary continuity, (2) strain

A space-time approach is proposed to simulate the propagation of brittle cracks in an isotropic and elastic solid in dynamics. We adopt the so called phase-field description of crack that is based on a variational representation of fracture mechanics. Due to this variational structure, the crack initiation and propagation can be then described thanks to a well chosen potential. In this approach, we

In this work, a novel finite element approach for the computational aeroelastic analysis of flexible lifting structures in subsonic flow is presented. The numerical simulation of the fluid-structure interaction relies on the physical concept and mathematical formulation of an aeroelastic beam element, that is based on Euler-Bernoulli and De Saint-Venant theories for the structure dynamics and modified

This study presents a topology optimization method for thermal actuators that accounts for boundary conditions influenced by variables such as thermal convection and pressure load. Thermal actuators with gripper-like designs are essential for handling hot and brittle materials. The objective of this study is to design actuator shapes that achieve an optimal balance between flexibility and stiffness

Significance of structural components with local abnormality in buckling analysis has drawn considerable interest from researchers. A versatile and effective non-uniform spline finite strip method (N-u SFSM) is developed to allow for mesh refinement in local zones, enabling a comprehensive analysis of buckling characteristics of structures with local abnormality. The inclusion of non-uniform spline

Bayesian methods have been widely used to improve the accuracy of finite element model in civil engineering. However, Bayesian methods generally suffer from the computational complexity involved in accurately identifying the posterior distribution. To address this issue, this paper proposes a novel method by combining the Hamiltonian Monte Carlo (HMC) algorithm with the gradient-enhanced Kriging (GEK)

Composite materials allow the production of structures with desired and improved properties (such as high strength), while minimizing the undesirable outcomes (e.g., increased weight). This ability to tune the properties of materials and structures has put composite materials under the spotlight in many fields, ranging from medical, automotive, aerospace, marine, and civil engineering applications

Previous multiscale concurrent topology optimization methods for thermoelastic structures were primarily based on static loading and steady-state heat transfer conditions, which do not account for transient effects associated with time-dependent loads. To address this limitation, this paper establishes a novel generic multiscale concurrent topology optimization method that incorporates transient thermoelastic

The structural ultimate load-bearing capacity plays an influential role in engineering applications. Melan’s static shakedown theorem offers a valuable approach for predicting the lower bound of shakedown loading factors and providing a safer shakedown domain when the structures are subjected to cyclic variable loads. However, the associated nonlinear mathematical programming is plagued by substantial

Performance envelopes provide a novel methodology that quantifies the load bearing capacity of a structure in a reduced dimension load space. The envelopes relate the complex loads acting on a structure to the corresponding structural failure constraints and may find many applications within the aircraft structural design process. Constructing envelopes for industrial problems is of particular interest

Data-driven methods for vibration-based Structural Health Monitoring (SHM) have gained significant popularity for their straightforward modeling process and real-time tracking capabilities. However, developing complex models such as deep neural networks can pose challenges, including limited interpretability and substantial computational demands, due to the large number of parameters and deep layer

The current study proposes a computational-based method to employ the non-classical micropolar continuum for modelling plates with in-plane functionally graded porosities. Initially, a homogenisation method is developed to derive the micropolar parameters of porous heterogenous plates based on strain energy equivalence in various designed deformations simulated via finite element analysis. The modelling

An extended formulation of the macro-element (ME) based models, representing for both adherends and adhesive along the entire overlap in only one four-node element, is presented. Compared to earlier modelling, continuum ME (CME) and discrete ME (DME) based models, the adherend parts are also modelled as plane continuum media, for which high order displacement fields are freely supposed. Both extended

Corrosion-induced material deterioration poses a pervasive threat to structural integrity, necessitating an in-depth understanding of its intricate behaviors. Pitting corrosion, a critical concern in this context, accelerates the degradation of materials. The limitations of conventional models arise from their neglect of the subsurface electrode boundary layer dynamics during the dissolution process

The time integration schemes, GA-23 and GA-234, recently proposed by the authors for first order problems, are extended to solve second-order problems in structural dynamics. The resulting methods maintain unconditional stability and user-controlled high-frequency damping. They offer improved accuracy and exhibit less numerical damping in the low-frequency regime, outperforming the well-known generalised-α

Strong imposition of Dirichlet boundary conditions for immersed finite element methods or immersed isogeometric methods remains a challenge. To address this issue, this paper presents a 3D conforming embedded isogeometric method for Boundary-Represented (B-Rep) solid CAD models by generalizing our bivariate B++ splines to trivariate B++ Splines. The proposed method can convert a B-Rep model into a

The main objective of this paper is to develop machine learning (ML) models for predicting the seismic responses of steel moment frames. For this purpose, four boosting ML techniques-gradient boosting, XGBoost, LightGBM, and CatBoost-were developed in Python. To create an inclusive dataset, 92,400 nonlinear time-history analyses were performed on 1,848 steel moment frames under 50 earthquakes using

Shakedown analysis is a powerful and efficient tool for calculating the safety factors of structures under variable and repeated external quasi-static loads, that can prevent structures from incremental and alternative plasticity collapses. RC slabs in practical engineering applications are usually under long-tern variable and cyclic loads, but their fatigue behavior was rarely reported in the literature

Understanding the effect of the material parameters variability on the mechanical response of laminated composites is of great importance for many engineering problems. Not only an accurate sensitivity analysis enables to estimate how much each parameter under consideration affects the response, but the linearization of the output provides also the possibility to, for example, use gradient-based optimization

An advanced analytical technique known as the Oblique Coordinate Wave Function Integral Method builds on Biot’s wave theory for saturated porous material, has been developed to address seismic wave scattering in irregular media. This method employs an integral representation of scattered waves, solved by using an oblique coordinate transformation within a rectangular coordinate system with wave function

A novel method is presented for estimating the bridge surface roughness scanned by a single-axle dual-wheeled 3D test vehicle and processed by an augmented Kalman filter (AKF). Two acceleration sensors are installed atop the axle near the two wheels of the vehicle to measure its vertical and rocking motions. Meanwhile, the Kalman filter algorithm is augmented specially for the vehicle-bridge interaction

Advanced construction technologies are creating opportunities to design and fabricate non-traditional concrete structural geometries. While removing structurally unnecessary material can aid in sustainability efforts, it can also reduce a structure’s ability to attenuate impact sound. An assessment of the impact sound insulation performance of custom concrete floors has often been excluded from previous

In this paper, the Dual Mesh Control Domain Method (DMCDM) put forward by Reddy is applied to solve linear static, free vibration, and buckling problems of functionally graded plates modeled using the First-Order Shear Deformation Theory (FSDT). The material properties are assumed to vary continuously through the thickness of the plate according to a power-law. Formulations are presented for linear

A combined Mode I-II cohesive zone (CZ) elasto-plastic constitutive model, and a two-dimensional (2D) cohesive interface element (CIE) are formulated and implemented at small strain within an ABAQUS User Element (UEL) for simulating 2D crack nucleation and propagation in fluid-saturated porous media. The CZ model mitigates problems of convergence for the global Newton-Raphson solver within ABAQUS,

The finite particle method (FPM), a novel numerical analysis approach for simulating structural statics and dynamics, is introduced into the field of structural optimization through the development of a new structural sensitivity analysis procedure. Using FPM, we can analyze static and dynamic structural responses, including typical nonlinear behaviors, based on a system composed of a finite number

This study introduces an offline iteration-based real-time hybrid simulation (OI-RTHS) method, a novel approach for simulating fluid–structure dynamic interaction (FSDI) under seismic excitation. With this method, hydrodynamic forces are treated as a physical substructure, while numerical computation and servo loading are performed independently throughout the entire duration of the seismic event.

Traffic loads are very critical in bridge digital twins for assessing the deterioration state and structural integrity of road bridges. The existing load rating methods are complicated and time-consuming, necessitating more efficient and intelligent approaches to identify and evaluate safe load capacities. This paper presents a digital twins-boosted approach to identify vehicle loads on road bridges

In the previous researches, the dispersion property of periodically layered media (PLM) is mainly represented by the frequency-wavenumber spectra. Here this paper studies the complete dispersion characteristics of elastic waves along arbitrary direction in space in periodically layered arbitrarily-anisotropic media (PLAM) by the comprehensive frequency-related dispersion surfaces and their profiles

This paper proposes a stress-constrained structural topology optimization method in the velocity field level set framework. To avoid the strength failure in structures, the stress should meet certain strength criteria at all material points. This point-wise constraint brings great difficulty to topology optimization. Instead of using the traditional aggregation scheme, we propose a new stress constraint

The exigencies of intricate environments necessitate the conception of structures exhibiting extraordinary performance. In response, we devised a foldable modular origami structure by combining Miura-Origami and perforated plates, employing a novel design strategy. We substantiated that this structure manifests adjustable Poisson’s ratios in diverse directions, spanning from negative values to positive

The performance of glue laminated bamboo (glubam) members is governed by the nonlinear response at their joints, where high deformation levels and stress concentrations are developed. Numerous phenomenological models are presently employed to describe the hysteresis behavior of these joints, while these models always have an excessive number of parameters, and the physical interpretation of these parameters

The idea of Phase Field Method (PFM) is introduced to depict the dynamic shear modulus degradation of saturated soil revealed in the undrained triaxial tests. The order parameter in PFM is adopted to govern the liquefaction process. Then the inherent and generalized constitutive relation among shear stress, shear strain, shear modulus and confining pressure is derived. It more complies to thermodynamics

This article introduces an extension to the Optimal Thickness Prediction (OTP) approach for solving the hybrid material composite laminate blending optimization problem considering both Buckling Factor and Failure Index constraints. The proposed optimization approach solves the blending optimization problem with a two-stage procedure. The Stacking Sequence of the laminate is first optimized using optimization

Aiming at the reanalysis problem of time-varying eigenvalues of force-shape coupled systems, this paper proposes an energy-preserving matrix perturbation theory (EPMPT) that can maintain the essential physical properties of the system. The classical matrix perturbation method, which employs interpolated shape functions, fails to evaluate and address solution errors promptly during the continuous perturbation

An implicit formulation for cylindrical joints (pivots) connecting slender rods in large deformations is presented exploiting the G1 map at the beam's end. The rotation at the end of the rod is decomposed in the rotation of the pivot axis and a rotation around this axis. A mixed variational formulation that uses the spherical linear interpolation for the rotations is implemented. It allows to effectively

While numerical physical models of contact mechanics have become increasingly prevalent, the implementation of these models to efficiently resolve geometric contact with a robust contact search strategy remains lacking. Our research endeavors to address this gap by introducing a comprehensive solution with an exact geometric contact mechanics algorithm for thin shell finite elements with an explicit

This study addresses the stability problem of long-span cable-supported bridges (CSBs) under live loads, which requires an accurate estimation of maximum girder deflection and rotation angle. In contrast to the cumbersome influence line method or analytical method, which ignores the structural nonlinearity of this bridge type or uses too many constraint conditions, we convert this problem into an optimization

In many engineering applications, the solution of acoustic wave problems in the infinite domain is required over a broad frequency range with densely sampled increments. In order to achieve efficient numerical simulations via a spatial discretization, e.g. finite element method, additional artificial absorbing boundaries are necessary to truncate the computational domain into appropriate bounded sizes

To design out-of-plane loaded masonry cladding panels, as well as modern non-loadbearing masonry panels, the yield-line method has become widely used by engineers, and features in various design codes. However, the traditional hand-based yield-line analysis method can be challenging to apply to complex or irregular shapes, since the form of the critical yield-line pattern will generally not be known

Limit analysis (LA) is successfully used for investigating the bearing capacity of reinforced concrete (RC) structures. Some cautions must be taken when using this method for RC since the concrete component exhibits a softening behavior with decreasing strength and limited ductility. A commonly adopted provision consists of considering isotropic reduced values of concrete strength to be input in the

This paper proposes an adaptive isogeometric topology optimization framework for shell structures by utilizing a continuous density field represented as Polynomial splines over Hierarchical T-meshes (PHT-splines). This framework ensures an exact representation of shell structures, eliminating the geometric inaccuracies commonly associated with topology optimization. In the meanwhile, the meshes used

Engineering structures are required to meet strength conditions to ensure engineering safety, where the maximum stress level of the structure mainly characterizes the structural strength. This study proposes an isogeometric topology optimization method for the local stress-constrained design. This method establishes an optimization model with volume fraction as the objective function and maximum von

The contribution at hand introduces a novel formulation that couples the Material Point Method (MPM) and Finite Element Method (FEM) based on nonlocal mechanics using an implicit time integration scheme. A constitutive formulation at finite deformations to describe fiber-reinforced concrete is applied. A damage approach within the microplane framework is utilized to capture the induced anisotropy in

Gears are one of the most widely used transmission components. Their operation relies on the contact between mating gear teeth flanks for the transmission of power. Accurate prediction of the contact stresses at these regions, is crucial for the design and dimensioning of these systems. Gear design is centered around highly smooth involute curves that greatly influence their contact behaviour. In this

Simulating the quasi-static mechanical behavior of concrete at the micro- or meso-scale, considering its heterogeneous nature, quickly becomes impractical in terms of computational cost. This manuscript explores efficient computational strategies in numerical modeling by means of the Lattice Discrete Particle Model (LDPM), a state-of-the-art approach for simulating concrete at the coarse aggregate

Reinforced concrete (RC) walls are vulnerable to severe damage under high-intensity, close-in TNT explosions. Substantial secondary fragments at high ejecting velocities could be generated from the damaged wall, posing serious threats to people, facilities and structures in the area. Predicting the blast-induced secondary fragments remains a great challenge. Traditional computational methods, such

The paper presents an efficient method for estimating the dynamic response of buildings due to train operations in tunnel. The proposed method involves four models to consider the transmission path in the train-track-tunnel-soil-pile-building chain: the vehicle model, track-tunnel-soil model, building model, and soil-structure interaction model. A series of theoretical methods are employed, including

The main research problem studied in this work is an uncertain response and reliability assessment of the spatial cable structures due to the environmental stochasticity as well as material and geometrical imperfections. Some popular cable structures are analyzed for this purpose using the Stochastic Finite Element Method (SFEM) implemented with the use of three different techniques, namely the iterative

This paper investigates the influence of vertical seismic accelerations on the seismic response of RC bridges through numerical simulations using an enhanced non-linear numerical model. Results confirm that the incorporation of vertical accelerations, either through actual records or scaled horizontal records, can considerably modify the seismic response and the collapse mechanism. In the case of actual

The inverse finite element method (iFEM) emerged as a powerful tool in shape-sensing and structural health monitoring (SHM) applications with distinct advantages over existing methodologies. In this study, a quadrilateral inverse-plate element is formulated via a sub-parametric approach using bi-linear and non-conforming cubic Hermite basis functions for engineering structures, which can be modeled

In this paper we extend the recently introduced mixed Hellan–Herrmann–Johnson (HHJ) method for nonlinear Koiter shells to nonlinear Naghdi shells by means of a hierarchical approach. The additional shearing degrees of freedom are discretized by H(curl)-conforming Nédélec finite elements entailing a shear locking free method. By linearizing the models we obtain in the small strain regime linear Kirchhoff–Love

This study introduces the vibration behavior of uniform functionally graded (FG) cylindrical shells by Jacobi-Ritz method. The first-order shear deformation theory (FSDT) and domain decomposition method (DDM) are used to establish the theoretical model. The complex constraint of FG cylindrical shells is realized by using artificial springs. The Jacobi orthogonal polynomials combined with Fourier series