FEM Software ABAQUS Research Articles

Structural Behaviour of Kenaf Fibre Lightweight Concrete Beams Modelling Via FEM-Abaqus

This study presents the structural properties of oil palm shell kenaf fibre Lightweight concrete (OPS-KFLC) beams. The main objective of this research was to investigate the potential advantage of kenaf fiber for improving the structure properties of OPS-RC beams. This investigation carried out by two methods experimental and consequently numerical modelling. The experimental work focused on two beams. First beam constructed with full shear reinforcement and without fibre (SI = 0% and with Vf = 0%) denoted as a control beam. Meanwhile one more beams with full shear reinforcement (SI = 0%) and with fibre volume fraction of Vf = 1% constructed respectively. The experimental work has been considered four point flexural tests on simply supported beam. Consequently, numerical modelling with finite element method FEM software Abaqus for calibration and validation of experiment results considered. First, sensitivity analysis (mesh and time) conducted up to acquire the best correlation with experimental result. Then, the experiments result of beams was used, for calibration in FEM modelling investigation. The results comparison showed that there is a good agreement between the experimental test and nonlinear finite element analysis NLFEA results. Generally, this investigation demonstrated up to 37% improvement on structure properties of OPS-RC beam by addition of Vf = 2%kenaf fiber.

Kinematic rigid plastic model for prediction of flexural response of RC beams including shear deformations

In this paper, an analytical model to determine the flexural response under four-point bending tests of simply supported RC beams failing in flexure and shear is presented. The model can provide the load-deflection curves, also including shear deformation; the latter is determined assuming a kinematic rigid plastic model able to consider strength contributions due to dowel action and transverse reinforcements with progressive yielding. For each contribution, a physical explanation is provided to link the strength contribution to a specific kinematic evolution of the overall response of the RC beam under combined shear and flexural loads. The nonlinear FEM software ABAQUS is also used for numerical analyses and comparison between the analytical model and available experimental results. Finally, an extensive numerical parametric analysis in comparison with the analytical predictions is made to check the reliability of the simplified proposed model, also in predicting the complete flexural response of beams including shear deformation contributions.

The Data-Driven Homogenization of Mohr–Coulomb Parameters Based on a Bayesian Optimized Back Propagation Artificial Neural Network (BP-ANN)

Homogenization methods can characterize the mechanical properties of these materials based on appropriate constitutive models and data. They are also applied to the characterization of mechanical parameters under complex geotechnical conditions in geotechnical engineering because of the complexity and heterogeneous nature of geotechnical materials. Unfortunately, existing homogenization methods for geotechnical mechanical parameters often incur immense computational costs. Hence, a framework that utilizes finite element analysis for generating a dataset which is then trained using a Bayesian Optimized Back Propagation Artificial Neural Network (BP-ANN) to obtain the homogenized Mohr–Coulomb parameters of the soils is proposed. This is the first time that Bayesian optimization and a BP-ANN have been used in conjunction to predict the homogenized mechanical parameters of soils. The dataset used for training the data is generated using the commercial FEM software ABAQUS (6.10). The maximum difference between the top and bottom part of the tunnel of the heterogeneous model and homogeneous model of our test cases only varies by 5.3%, thereby verifying the excellence of the Bayesian Optimized BP-ANN.

Analytical solution for seismic response of deep tunnels covered by an isolation layer subjected to SH waves

AbstractThe paper presented a novel analytical solution to evaluate the seismic‐induced stresses and displacements of tunnels covered by an isolation coating layer subjected to SH waves. The solution is derived based on the assumptions that the ground, isolation coating layer, and liner are linear elastic and in steady‐state motion. The analytical solution is obtained using the Bessel‐Fourier series. Comparisons are made between the seismic responses of tunnels obtained using the proposed analytical solution and those of the simulation results from the FEM software ABAQUS. Additionally, the proposed solution is also compared with the known degraded solution from the literature to validate its accuracy. The influence of various key factors, such as the Young's modulus ratio between the coating layer and the ground, the thickness of the coating layer, and the relative stiffness between the ground and the liner, on the seismic response of tunnels are investigated using the proposed analytical solution.

Settlement of masonry barrel vaults: an experimental and numerical study

The paper deals with a experimental and numerical study of a masonry barrel vault subjected to an incremental horizontal settlement of one abutment. The analyzed vault is very slender and with no backfill, as is typical of the vaulted roofs covering many Italian churches and other religious buildings of various dimensions, that often suffer a certain amount of settlement due to the deformation of the sustaining walls. In this paper, the experimental tests conducted at the University of Florence on a full-scale specimen has been assumed as a benchmark for numerical simulations carried out via different models, some implemented in the general purpose FEM software (Abaqus), and others specifically developed for masonry structures (Mady). The capability of the considered models to describe the actual behavior of the vault has been investigated, and their potential highlighted.

Numerical Analysis of Splitting Tensile Strength of Steel Fibre Reinforced Concrete under Static Loading

This paper presents the study on the numerical analysis of splitting tensile strength test of steel fibre reinforced concrete under static loading. ABAQUS FEM software is used to model the test configuration for plain concrete and steel fibre reinforced concrete (SFRC) based on the experimental investigations that studied the effectiveness of adding steel fibres of 1.5% volume fraction into the concrete mix. Four 3D models are created which are brick concrete, brick SFRC, stone concrete and stone SFRC. The numerical analysis results are compared with the published experimental results in terms of splitting tensile strength, tensile stress-strain relationship and tensile damage. The splitting tensile strengths from horizontal stress output are found to be slightly lower compared to the experimental results with percentage difference of less than 15%. While the results from using analytical formula also underestimate the splitting tensile strength with percentage difference up to 22% when compared to the experimental results. Elastic modulus from tensile experimental results should be taken as Young’s modulus of the model since it gives results that are closer to experimental results. The Poisson’s ratio that gives the closest results to the experimental result is taken as the Poisson’s ratio of the concrete and SFRC. The adopted 3D model captured reasonably well the reaction of the concrete cylinders subjected to splitting tensile test. Numerical analysis displays a strong correlation with the experimental results after proper evaluations and realistic optimizations of the governing parameters through extensive analyses.

An analytical approach to global buckling of ring-stiffened sandwich cylindrical shells

In this paper, an analytical approach for global buckling of ring-stiffened sandwich cylindrical shells is presented with layerwise theory (LWT). Appropriate displacement functions are assumed according to the boundary conditions and the deformation characteristics of the inner and outer shells. The strain energies of the inner and outer shells and the ribs and the work done by external forces are derived with the help of classical laminate theory. Furthermore, the Rayleigh–Ritz method is employed to obtain the critical buckling load of ring-stiffened sandwich cylindrical shells. The ribband width has a great influence on the precision of calculation of the critical buckling load, and a formula for calculating this width is obtained by data fitting. To confirm the accuracy of the proposed formulation, a numerical simulation is carried out by using Abaqus FEM software. The results show that the proposed approach has high accuracy in predicting the global buckling behavior of ring-stiffened sandwich cylindrical shells. Finally, the effects on the buckling performance of ring-stiffened sandwich cylindrical shells caused by changing the inner and outer shell thicknesses and the rib height, thickness, and spacing are explored.

Large amplitude vibration of annular and circular functionally graded composite plates under cooling thermal shocks

In this paper, large amplitude thermally induced vibration (TIV) of annular and circular plates is analyzed under cooling shocks. A novel comparison of the TIV response is presented under rapid cooling and heating shock loads. This is the first time that TIV study has been presented for any flexural structure under thermal cooling. Structures can experience cooling shock loads in many circumstances, for example when exposed to spills of cryogenic liquids. The functionally graded composite plates are made of 304 grade stainless steel (SUS304) and low-carbon steel (AISI1020) and are graded through the plate thickness to have a continuously varying spatial composition profile in thickness direction. Thermo-mechanical properties are assumed to be temperature dependent. The plates are modeled using first-order shear deformation theory with von Karman geometric nonlinearity. The Generalized Differential Quadrature Method (GDQM) and Newton–Raphson technique are employed to solve the governing equations. A Fourier heat equation is used to evaluate temperature distribution over time using GDQM and Crank–Nicolson approaches. The validation study is conducted based on the literature and FEM software ABAQUS. Detailed parametric study is presented focusing on the effect of thermal shock magnitude, rapidity of the thermal shock application, plate geometry, material distribution, geometrical nonlinearity and temperature dependency of material properties. Differences in the response due to these factors have been shown between cooling and heating thermal loads. Results show that importance of the inertia effect is substantially higher under sudden cooling than it is under sudden heating, for the same thermal load magnitude and rapidity of thermal shock. Moreover, it is shown that stresses induced by thermal cooling can potentially reach yield strength of the material with relatively large amplitudes of fluctuations. Therefore, to estimate realistically the structural behavior of thin/slender plates under rapid cooling, the inertia effect should be taken into the account and TIV analysis needs to be performed.

High-accuracy design for mesh antennas considering the metallic mesh

Metallic meshes have great effects on the surface accuracy and tension distribution of mesh antennas, which present considerable challenges to the high-accuracy design of reflectors. Unfortunately, the metallic mesh is usually neglected in current research due to the complex coupling between the metallic mesh and the cable network. This paper presents a novel high-accuracy design method for the mesh reflector considering the effect of the metallic mesh. A cable-membrane coupling model is first proposed to account for the compatible deformation between the cable network and the metallic mesh. By introducing the topology matrix of the cable-membrane structure, the unified equilibrium equation of the mesh antenna is established and solved by the dynamic relaxation (DR) method. A novel high-accuracy design method for the mesh antenna is proposed by optimising the geometric dimensions of the cables and the membranes. Finally, this method is effectively applied to the high-accuracy design of two mesh antennas with different topologies considering the effect of the metallic mesh. The superiority of the method is demonstrated through a comparison with the literature, and the accuracy of the results is exhibited by the FEM software ABAQUS.

Analysis of bamboo tensegrity structures

Tensegrity is a futuristic structural principle based on a system of isolated components under compression and tension within a continuous network system. The theory and practice of tensegrity in structures are vast. The incorporation of sustainability into the design of structures is an immediate requirement. The structures are expected to be sustainable, recyclable, compact, economical, and futuristic in design. This research involves the creation and analysis of a bamboo tensegrity model. The engineered structure is designed with minimal materials and maximum geometrical principles in mind, contributing to modern engineering. The tensegrity structure is made of eco-friendly and vernacular materials such as bamboo and jute, which benefits regional economies and sustainable industrialization. The tensegrity structure can be effortlessly dismantled and is portable, making it simple to deploy. It has a number of both temporary and permanent applications. In this paper, the FEM software Abaqus was used to study a numerical analysis of a tensegrity structure model under loading, and two prototype were also developed. The floating elements add artistic value to the prototype model, making it appealing and futuristic.

Single Pile FEM Modeling: Ultimate Capacity Determination of Bored Piles Embedded in Silty-Sands Using Modified Drucker-Prager Cap Model

Ultimate pile capacity determination is crucial before the structure construction. This essential pile resistance can be accurately predicted and studied using the finite element method. FEM is a numerical method that is anticipated to be indispensable in advances in pile analyses, aiming at pile effectiveness and material efficiency. Pile modeling is attainable using FEM for the stability investigation concerning the geotechnical findings. In addition, several constitutive mathematical models have been available for FEM applications to reasonably simulate soil behavior under pressure. This study conducts numerical modeling of eight bored piles of different diameters and lengths embedded in silty-sand soils. Using the FEM software ABAQUS, pile load-settlement curves are obtained to determine ultimate pile capacity, skin friction resistance, and pile base resistance. The modified Drucker Prager Cap model is used as a constitutive soil model for silty sand soils. In applying the MDPC model, the cap hardening behavior (hardening parameter) is obtained by having the site soils compression and swelling indices determined using the proposed regression equations in the literature. Piles were modeled successfully, and the results positively correlate with the results of the dynamic analysis test conducted in Davao del Norte, Philippines.

STUDY ON ADJUSTABLE CONNECTOR OF RECIPROCAL FRAME

In this paper, we design an adjustable connector of reciprocal frame, and a three-dimensional solid model of this connector with Circular Hollow Section has been created in the FEM software Abaqus CAE to study its mechanical properties. When the plastic hinge is formed at the end of the Circular Hollow Section, the connector is still in an elastic state. It is concluded that the adjustable connector of reciprocal frame has high strength and rigidity, realizing the goal for designing higher connector strength over Circular Hollow Section strength. Then parametric analysis is used to analyse the influence of the connector about each part on the mechanical properties, and the flexural rigidity of the connector has been derived. A three-dimensional wire model of reciprocal frames has been created in the FEM software Abaqus CAE, and a full-scale test model of the structure is designed. The numerical simulation results agree well with the test results. It is verified that the reliability of the modeling method and the accuracy of the connector mechanical model.

Numerical study of visco-hyperelastic damper with high axial damping rubber subjected to harmonic loading

Structural control prevents structural damage and provides the desirable performance level through the ductility of components and using passive energy dissipation systems. In this paper, the performance of a recently introduced passive control device called Visco-Hyperelastic Damper (VHD) is investigated by ABAQUS FEM software. This device has the properties of both velocity-dependent and displacement-dependent dampers and provides additional energy dissipation for structures. This device consists of a viscoelastic material sandwiched between two metal rings dissipating energy through a combination of the elastic behavior of the viscoelastic material and the plastic deformation of the steel parts. In order to validate the numerical model, after separately testing the steel and rubber parts, their results are used in damper modeling. VHD performs desirably under different levels of excitation such that 82% to 99% of energy dissipation, depending on the type of loading, is observed by this device. The dynamic behavior of VHD can be further improved by modifying variable parameters such as dimensions and type of materials of the device.

Model design and finite element analysis of a traction link of a railcar

The traction link is a key component of the railcar suspension system which is used to transmit force and provide acoustic and vibration isolation. To ensure satisfactory performance of the railcar suspension system, the traction link should be properly designed. In this study, the traction link is considered as a component for local manufacturing. The aim of this study is to provide a guided approach on the design and simulation of the part to ensure that it meets the service and functional requirements. To clearly understand the effect of vibration and variable alternating loading on the mechanical integrity of the railcar suspension system, the designed traction link was analysed using finite element analysis. Dynamic analysis on the traction link was done using a linear perturbation analysis tool in the commercial FEM software ABAQUS©. The results show that the component is designed to a safe limit for the required service condition and that the material chosen is unlikely to deform under extreme conditions of the system. It is envisaged that the findings of this study will assist manufacturers in the development of railcar suspensions system that will meet the required service conditions.

Damage Optimisation for Air Bending

AbstractLoad and shape optimisation are applied to the process of air bending to optimise the damage state in the formed component. The enhanced process of elastomer bending is optimised, which yields a reduced damage state due to the superimposed radial stresses in the critical area of the forming process. The optimisation presented here is twofold. First, the elastomer is replaced by nodal loads to generate optimised loads for a reduced damage state. Second, the elastomer itself is optimised via shape optimisation by adjusting the layer for two kinds of elastomer of varying stiffness. The optimisation is accomplished with the commercial FEM software Abaqus as the solver for the mechanical problem and Matlab is used for optimisation.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ МЕТОДИК МОДЕЛИРОВАНИЯ ПРОЦЕССА РЕЗАНИЯ С ИСПОЛЬЗОВАНИЕМ ПРОГРАММНЫХ СРЕДСТВ

The paper presents an analytical study for comparing different numerical methods used for the modeling of cutting process using finite element method. The aims of this study is to compare capabilities of FE software package (Deform, AdvantEdge, ANSYS Workbench and ABAQUS). The main stages of modeling are discussed, as well as well-known methods and approaches used for their implementation. Main formulations for description of motion of deformable materials are analyzed to Lagrangian approach, Eulerian approach, Arbitrary Lagrangian Eulerian (ALE) approach. Numerical techniques to model chip separation are grouped as geometrical and physical. In this paper two strategies for time integration, implicit and explicit schemes are reviewed. Various models of friction between the chip and the tool are discussed: Amonton-Coulomb's Law, Prandtl's Law and Zorev. In this work, modeling and simulation of cutting process is carried out by FEM software ABAQUS. As a result of modeling, the stress and strain fields for both the workpiece and the tool are presented, as well as the thermal field of the workpiece and the chip. The numerical results obtained are compared with the results have been carried out previously using software ANSYS Workbench. The numerical values of temperatures, stresses and deformations correspond to traditional concepts of the cutting process, as well as experimental data presented in open sources.

JuSFEM: A Julia-based open-source package of parallel Smoothed Finite Element Method (S-FEM) for elastic problems

The Smoothed Finite Element Method (S-FEM) proposed by Liu G.R. can achieve more accurate results than the conventional FEM. Currently, much commercial software and many open-source packages have been developed to analyze various science and engineering problems using the FEM. However, there is little work focusing on designing and developing software or packages for the S-FEM. In this paper, we design and implement an open-source package of the parallel S-FEM for elastic problems by utilizing the Julia language on multi-core CPU. The Julia language is a fast, easy-to-use, and open-source programming language that was originally designed for high-performance computing. We term our package as juSFEM. To the best of the authors’ knowledge, juSFEM is the first package of parallel S-FEM developed with the Julia language. To verify the correctness and evaluate the efficiency of juSFEM, two groups of benchmark tests are conducted. The benchmark results show that (1) juSFEM can achieve accurate results when compared to commercial FEM software ABAQUS, and (2) juSFEM only requires 543 s to calculate the displacements of a 3D elastic cantilever beam model which is composed of approximately 2 million tetrahedral elements, while in contrast the commercial FEM software needs 930 s for the same calculation model; (3) the parallel juSFEM executed on the 24-core CPU is approximately 20× faster than the corresponding serial version. Moreover, the structure and function of juSFEM are easily modularized, and the code in juSFEM is clear and readable, which is convenient for further development.

A numerical study on the influences of underlying soil and backfill characteristics on the dynamic behaviour of typical integral bridges

Abstract The identification of the dynamic behaviour of a structure is one of the crucial steps in the design of the dynamic resistance of the structure. The dynamic behaviour is represented by the natural frequencies and damping which are subsequently used along with the considered dynamic actions in the design process. In regard of integral bridge concept, one of the consequences of the omission of joints and bearings is the substantial soil-structure interaction which in turn increases the sensitivity of the dynamic behaviour of the bridges to the surrounding soil characteristic. In this article, we extended our hybrid BEM-FEM steady-state dynamic numerical tool to the 3D regime, developed by utilizing an in-house BEM and the commercial FEM software ABAQUS and use it to analyse the dynamic interaction between the bridge and the underlying soil as well as the backfill. The numerical results from four typical integral bridges show that underlying soil characteristic has great effect on the resonant frequencies and the damping. The backfill material properties tend to have less significant role due to the abutment wingwalls dominating the force transfer between the soil and the superstructure. The results also show that the degree of influence of the soil-structure interaction on the coupled system is affected by the type of load pattern in addition to the flexural stiffness of the superstructure.

Numerical modelling of fluid transportation based on digital core model

Rock pore is the storage space and migration channel of geo-fluid resource like petroleum, coalbed methane and shale gas etc. In this paper, the rock core microscopic pore structure based on CT image is studied through image processing. Then the parameters are analyzed statistically by numerical modelling. The reconstructed software Mimics is used to reconstruct the core structural model. Finally, the relationship between the pore structure parameters and penetrability is studied by numerical simulation. The equivalent permeability of the reconstructed core is calculated by using FEM software Abaqus. The results shown that fluid percolation is directly related with porosity, pore shape, pore conectivity. The permeability of core can be obtained by substituting flow numerical simulation for seepage laboratory experiment.

Vibration analysis of fiber reinforced composite hydrofoils using finite element method

In this study, the natural responses of fiber reinforced composite hydrofoils are obtained using FEM. It is of great importance to estimate the vibrational responses of fiber reinforced composite hydrofoils correctly due to the flexible characteristics of the material. Modal analysis is performed on a cantilevered hydrofoil which has a cross-section of a modified NACA0009 profile using FEM software Abaqus 2019. Newly developed structured mesh modeling method is used, and the results are compared with the conventional modeling methods and experiment. In the developed mesh model, boundaries of the layers are modified in order to apply a structured mesh. By investigating the stress distribution of the hydrofoil for the bending mode case, it is evident that the developed mesh model results in the most accurate and physical result compared to existing modeling method.