Finite Element Analysis Of Beams Research Articles

Prediction and control of fracture paths in disordered architected materials using graph neural networks

Architected materials typically rely on regular periodic patterns to achieve improved mechanical properties such as stiffness or fracture toughness. Here we introduce a class of irregular cellular materials with engineered topological and geometrical disorder, which represents a shift from conventional designs. We first develop a graph learning model for predicting the fracture path in these architected materials. The model employs a graph convolution for spatial message passing and a gated recurrent unit architecture for temporal dependence. Once trained on data gleaned from experimentally validated elastoplastic beam finite element analyses, the learned model produces accurate predictions overcoming the need for expensive finite element calculations. We finally leverage the trained model in combination with a downstream optimization scheme to generate optimal architectures that maximize the crack path length and, hence, the associated fracture energy.

Design and Analysis of Multifidelity Finite Element Simulations

Abstract The numerical accuracy of finite element analysis (FEA) depends on the number of finite elements used in the discretization of the space, which can be varied using the mesh size. The larger the number of elements, the more accurate the results are. However, the computational cost increases with the number of elements. In current practice, the experimenter chooses a mesh size that is expected to produce a reasonably accurate result, and for which the computer simulation can be completed in a reasonable amount of time. Improvements to this approach have been proposed using multifidelity modeling by choosing two or three mesh sizes. However, mesh size is a continuous parameter, and therefore, multifidelity simulations can be performed easily by choosing a different value for the mesh size for each of the simulations. In this article, we develop a method to optimally find the mesh sizes for each simulation and satisfy the same time constraints as a single or a double mesh size experiment. A range of different mesh sizes used in the proposed method allows one to fit multifidelity models more reliably and predict the outcome when meshes approach infinitesimally small, which is impossible to achieve in actual simulations. We illustrate our approach using an analytical function and a cantilever beam finite element analysis experiment.

New robust and efficient global iterations for large deformation finite element analysis of beams and shells with material nonlinearity

In large rotation analyses of beams and shells with displacement-based discretization, the iterative burden grows considerably with the membrane/flexural stiffness ratio. For linear elastic materials, it was shown that a stress–displacement iteration solves this issue and reduces the computational cost even of several times. Convergence problems occur also when large rotations are coupled to material nonlinearity, even if this case is not well addressed in the literature. The extension of the mixed iteration to large deformation problems with nonlinear constitutive laws is faced in this work, focusing on elastoplasticity. New iterative schemes are derived for both displacement-based finite elements (DFEs) and mixed finite elements (MFEs), each featuring further variables in the linearization along with displacements. For DFEs, it is shown that the most convenient approach is to impose the constitutive law for an independent integration point strain, with the strain–displacement compatibility solved together with the global equilibrium. For MFEs, as an extension of this strategy, the most performing scheme solves element compatibility and global equilibrium simultaneously, with the element state evaluated for independent strains work-conjugate of the stress DOFs. In both cases, global linear systems in displacements only are required and strain-driven material laws are easily considered. Numerous tests validate the proposed iterative schemes showing a significant reduction of the computational cost compared to standard approaches.

Finite element analysis of beam with different loading condition

Abstract This examination researches the diversion and the stressful appropriation in a length, thin cantilever beam or bar light emission rectangular cross section segment made of straight versatile the material behavior and mechanical properties that are homogeneous mixture. The redirections of a beam are basically a modeling of 3D issue. A flexible extending one way is joined by a pressure in opposite ways. This undertaking, structural and dynamic examination is a cycle to decide the stress, strain and distortion. Shaking qualities of a formation or a machine segment while it is being planned. It was gotten a significant choice to give an accommodating commitment in understanding control of numerous vibration wonders which experienced practically speaking. In present work we thought about the pressure and regular recurrence for various material have identical cross sectional area of the shafts are T, I and C shaft. The beam is planned and dissected in ANSYS 14.0 software. The beam shaft is fixed toward one side is vibrate to acquire the normal recurrence, modal shape in addition to redirection by the various segments and equipment.

Finite Element Analysis of Beams Reinforced with Banana Fiber Bars (BFB)

One of the challenges of the century is to reach compatibility between the required resistance and the usage of lightweight building materials that may negatively affect the mechanical properties. Natural fibers nowadays are used as enhancers in the industrial field. Hence, the fibers contribute by giving an ideal solution to improve mechanical proprieties of the structural elements such as tensile and impact strength. In previous studies, the use of natural fibers as reinforcement in construction materials has increased. Natural fibers have a lot of characteristics such as being strong, lightweight, inexpensive, and eco-friendly. This paper aims to investigate the performance of banana fiber bars (BFB) as reinforced material. Through this study, the development and characterization of natural fibers-based composite beams were observed. After the beams were designed, several types of finite element analysis were conducted using ‘ANSYS’ nonlinear finite element program under one-point loading. Results show good correlations between experimental and predicted results.

Finite Element Analysis of Beam – Column Joints Reinforced with GFRP Reinforcements

Glass Fibre Reinforcement Polymer (GFRP) reinforcements are currently used as internal reinforcements for all flexural members due to their resistance to corrosion, high strength to weight ratios, the ability to handle easily and better fatigue performance under repeated loading conditions. Further, these GFRP reinforcements prove to be the better alternative to conventional reinforcements. The design methodology for flexural components has already come in the form of codal specifications. But the design code has not been specified for beam-column joints reinforced internally with GFRP reinforcements. The present study is aimed to assess the behaviour of exterior beam-column joint reinforced internally with GFRP reinforcements numerically using the ABAQUS software for different properties of materials, loading and support conditions. The mechanical properties of these reinforcements are well documented and are utilized for modelling analysis. Although plenty of literature is available for predicting the joint shear strength of beam-column joints reinforced with conventional reinforcements numerically, but no such study is carried for GFRP reinforced beam-columns joints. As an attempt, modelling of beam-column joint with steel and with GFRP rebars is carried out using ABAQUS software. The behaviour of joints under monotonically increasing static and cyclic load conditions. Interpretation of all analytical findings with results obtained from experiments. The analysis and design of beam-column joints reinforced with GFRP reinforcements are carried out by strut and tie model. Strut and Tie models are based on the models for the steel reinforced beam-column joints. The resulting strut and tie model developed for the GFRP reinforced beam-column joints predicts joint shear strength. Joint shear strength values obtained from the experiments are compared with the analytical results for both the beam-column joints reinforced with steel and GFRP reinforcements. The joint shear strength predicted by the analytical tool ABAQUS is also validated with experimental results.

Multilayered models for determining the Young's modulus of thin films by means of Impulse Excitation Technique

This work presents a methodology to determine the Young's modulus of an individual coating in a multilayered system by means of the Impulse Excitation Technique (IET). In this technique, the composite beam is excited by an impulse and the frequencies of the first four bending modes are extracted. They are used in a one-dimensional model to obtain the Young's modulus of the coating. Based on two different theories: the Flexural Rigidity of a Composite Beam (FRCB) and the Classical Laminated Beam Theory (CLBT), different models proposed in the literature for bilayer beams have been extended to describe a beam composed of N dissimilar layers. Moreover, an enhanced model was developed based on the laminated theory. It takes into account the shift of the neutral axis after each deposited film, which makes it applicable for any film thickness. The reliability of the proposed model is investigated by comparing its predicted frequency to those of existing models for bilayers. It is also compared to finite element analysis of beams composed of two and three dissimilar layers. A metrological study was performed to quantify the most influencing factors on the global uncertainty. The methodology was applied to beams composed of three layers (N = 3) with titanium and niobium thin films deposited by DC magnetron sputtering. The most accurate models are applied to obtain the Young's modulus of Ti and Nb films in the Ti/Nb/(AISI 316 or Glass) multilayer beam. The films microstructure and morphology were analyzed by X-ray diffraction and scanning electron microscopy.

Buckling behaviour of thin-walled laminated composite beams having open and closed sections subjected to axial and end moment loading

An efficient modelling technique based on one dimensional (1D) beam finite element analysis for buckling of thin-walled laminated composite beams having open/closed sections is proposed. The formulation derived has sufficient generality for accommodating arbitrary stacking sequences of the individual beam section walls, and includes all possible couplings between axial, shear, bending and torsional modes of deformation. The effects of transverse shear deformation of the section walls and out-of-plane warping of the beam section are considered where provision exists to restrain or allow warping deformation. The incorporation of shear deformation leads to a problem in the finite element implementation of the proposed beam kinematics, but this is successfully addressed adopting a novel modelling concept. Numerical results obtained for the sample cases of open sections I beams and closed section box beams are presented. The numerical results are benchmarked/compared to data available in open literature, and it is shown that the proposed model performs very well. Finally, a study of the effect of axial and end moment loading, acting alone or in combination, on the buckling response of thin-walled composite beams is presented.

Finite Element Analysis of Beam to Column Bolted Connection – A Review

Objectives: This paper contains the review of studies performed on the behavior of steel beam-to-column connections by using finite element analysis computer package known as “Abaqus, Ansys, etc” from the theoretical and practical points of view. The objective of this article is providing the foundation for the design and analysis faster and more economical and securing the required strength for the connection steel. Methods/Statistical Analysis: Nearly seventy-one academic and popular research/literature in the field of steel connections had been studied in which an overview of recent events has made the construction of the system viable in the infrastructure. Findings: Linear analysis of connection behavior is very complicated since there is no immediate solution for it. All the results of the accounts of the design connections cannot be verified only through lab tests which consume a lot of time, money and effort. Therefore, the availability of simulation programs can overcome these problems. This article will be of value to anyone seeking better understanding in the area of steel beam-to-column connections behavior. Application/Improvements: Review study presented in this paper can be used as reference for future investigation especially in the member strength and development of the design approach for steel beam-to-column connections with simulation models.

Crack Detection in Cantilever Shaft Beam Using Natural Frequency

Crack is one of the major factors that lead to failure of a machine component. Today, failure of shaft mostly takes place due to material fatigue. Different characteristics of vibration can be used to detect crack in beams. But a question that still remains that which is most sensitive that can be used for damage detection .In present work finite element analysis of beam using Ansys14.5 is done and first three natural frequencies of transverse mode are extracted. Based on which the behaviour of healthy and cracked beam is compared and concluded that natural frequency of transverse vibrations could be used to detect crack in cantilever shaft beam.

Performance of consistent through-thickness electric potential distribution for Euler-Bernoulli piezoelectric beam finite elements

An accurate piezoelectric beam finite element analysis essentially requires appropriate assumptions of the field variables involved in the formulation. The conventional Euler-Bernoulli piezoelectric beam finite elements assume an independent linear through-thickness distribution of electric potential in a physical piezoelectric layer which is actually nonlinear due to induced potential effects. Here, a consistent through-thickness potential distribution in a physical piezoelectric layer derived from the electrostatic equilibrium equation is tested for its accuracy against the linear assumption. This consistent potential field contains, in addition to the conventional linear terms, a higher order term coupled with bending strain. Thus, this finite element, though employing higher order potential, does not increase the number of nodal electrical degrees of freedom. It is shown that the performance of the present formulation with consistent through-thickness potential is insensitive to the geometric configuration and material properties of the beam cross-section, unlike the conventional formulations.

Performance of consistent through-thickness electric potential distribution for Euler-Bernoulli piezoelectric beam finite elements

An accurate piezoelectric beam finite element analysis essentially requires appropriate assumptions of the field variables involved in the formulation. The conventional Euler-Bernoulli piezoelectric beam finite elements assume an independent linear through-thickness distribution of electric potential in a physical piezoelectric layer which is actually nonlinear due to induced potential effects. Here, a consistent through-thickness potential distribution in a physical piezoelectric layer derived from the electrostatic equilibrium equation is tested for its accuracy against the linear assumption. This consistent potential field contains, in addition to the conventional linear terms, a higher order term coupled with bending strain. Thus, this finite element, though employing higher order potential, does not increase the number of nodal electrical degrees of freedom. It is shown that the performance of the present formulation with consistent through-thickness potential is insensitive to the geometric configuration and material properties of the beam cross-section, unlike the conventional formulations.

Bending–shear interaction in short coupling steel beams with reduced beam section

In current design provisions, the plastic moment and rotation capacity of plastic hinges for beams must not be decrease due to compressive and/or shear forces. For the majority of moment-resisting frames, the influence of shear and axial forces on the bending moment and rotational capacity of plastic hinges can be ignored, because the shear and axial forces typically observed are low relative to the shear and axial capacities. However, in some cases, the lateral force-resisting systems are composed of closely spaced columns rigidly connected by short steel beams. Each of these beams is long enough to allow the development of plastic moment hinges at the ends, but also short enough to develop significant shear forces that can influence the bending moment and rotational capacity of the beam.This report presents a parametric study conducted using an experimentally calibrated numerical model, performed at the CEMSIG Research Centre (http://www.ct.upt.ro/en/centre/cemsig) at the Politehnica University of Timisoara. The study observes and characterizes the plastic mechanism of short steel beams with reduced beam sections (RBS) applied in moment-resisting frames. A simplified and reliable alternative allowing the use of beam finite element analysis (FEA) for bending–shear interactions is proposed.

English

English

Experimental research on bending performance of structural cable

Studies on bending properties of cables have long history but those researches are mainly around electrical conductors with very limit experimental discussions on structural cables. One approach on dynamic problems are through understanding changes in bending stiffness and utilized the varying bending rigidity into beam theory or beam finite element analysis. Therefore, a serial of quasi-static bending tests on semi-parallel wire cables, stranded ropes and steel spiral strands (Galfan) were performed to understand the cable bending response, with considering different factors like end conditions and the present and magnitude of pretension. The effective flexural stiffness of those structural cables were then determined and compared. Test results indicated that the unstressed cables under bending had an elastic–plastic like force–displacement response, which was analogous to an elastic–plastic metallic beam. Galfan strands showed better wire bounding behavior and cooperative bending due to different winding method. Welded end measurements can add integrity to the cable but this strengthening effect is weak and limited. Flexural response of the cable under a constant tension force was more like a linear relation with sag deflection. Pretension can increase the cable flexural stiffness, and this strengthening effect increased with the pretension level but decrease with the cable dimension. A simplified evaluation method of effective flexural stiffness was also proposed.

Vibration of thin-walled laminated composite beams having open and closed sections

An efficient technique based on one dimensional beam finite element analysis for vibration of thin-walled laminated composite beams having open and closed sections is proposed in this paper. The developed technique is quite generic which can accommodate any stacking sequence of individual walls and considers all possible couplings between different modes of deformation. The formulation has accommodated the effect of transverse shear deformation of walls as well as out of plane warping of the beam section where the warping can be restrained or released. The inclusion of shear deformation has imposed a problem in the finite element formulation of the beam which is solved successfully utilising a concept developed by one of the authors. A number of numerical examples of open section (I and C sections) beams and closed section box beams are solved by the proposed technique and the results predicted by the proposed model are compared with those obtained from literature as well as detailed finite element analysis using a commercial code. The results show a very good performance of the proposed modelling technique.

Beam-element-based analysis of locally and/or distortionally buckled members: Application

The companion paper [1] presents a theory to account for the effects of local and/or distortional buckling in a seven degrees of freedom beam finite element analysis. The theory considers the effect of local and/or distortional buckling as a reduction in tangent rigidities, and determines the reduced tangent rigidities by an a priori post-local or post-distortional buckling analysis of a short length of section. In this paper, the presented method is incorporated into the open source software package OpenSees which was previously modified to account for warping effects [2]. The accuracy of the method is validated by comparison with shell element results for beams, columns and frames.

A model for warping transmission through joints of steel frames

A simple approach is developed in this paper which considers the effect of partial warping continuity through the joints of thin-walled steel frames when using beam finite element analysis. Using a condensed stiffness matrix for the joint generated by the substructuring technique, warping springs are introduced to represent the condition of partial warping restraint at intersections between members. The performance of the proposed model is demonstrated through a number of numerical examples. Excellent agreement is achieved between the results of beam finite element analysis using the suggested joint model and accurate shell finite element analysis.

Experimental and Analytical Investigations on Flexural Behaviour of Retrofitted Reinforced Concrete Beams with Geopolymer Concrete Composites

Existing multi-storey buildings in earthquake prone regions of India are vulnerable to severe damage under earthquakes. So there is an urgent need for retrofitting of deficient and damaged buildings. Portland cement (PC) production is under critical review due to high amount of carbon dioxide gas released to the atmosphere and Portland cement is also one among the most energy-intensive construction material. The current contribution of greenhouse gas emission from Portland cement production is about 1.5 billion tons annually or about 7% of the total greenhouse gas emissions to the earth’s atmosphere. So retrofitting of existing deficient building using eco-friendly material which could promise higher structural performance than the original building is essential.Geopolymer concrete (GPC) is a non-Portland cement binder based on alkaline activation of industrial wastes such as fly ash and GGBS. The application Geopolymer concrete in retrofitting can reduce the production of cement and can create an ecofriendly construction atmosphere to an extent. So the feasibility of geopolymer concrete in retrofitting of damaged structures is required to be studied. This paper presents the details of the mix designs of GPC mixes, preparation of retrofitted test specimen, testing and evaluation with respect to cracking, ultimate load, deflection and failure modes. Non-linear finite element analysis of beams by 3D modeling of concrete (solid 65 element) and discrete modeling of reinforcement (Link 8 element) was carried out using ANSYS software. The load deflection characteristics, failure modes and crack patterns are obtained from the experimental and analytical studies. The results of the study indicate that the performance of retrofitted beam with GPC and control beam shows good agreement in ultimate load, failure modes and crack patterns.

Buckling analysis on the hull of the historic paddle steamer ‘Medway Queen’

This study presents modelling and finite element simulation and the subsequent buckling analysis on the the historic Medway Queen paddle steamer ship which is under reconstruction now. The objective of this study is to assess buckling strength of the hull plate due to the longitudinal stress in the hull plates of the Medway Queen under various sea and live load conditions. A beam finite element analysis with structural elements is utilised to assess shear stress and bending moments of the ship structure. The model predictions for longitudinal stresses in hull plates are combined with buckling assessments on the hull plates in different, judged to be the most critical, locations along the ship's length. The structural beam model is utilised to simulate the ship's stress behaviour under hogging and sagging conditions with three different wave heights and four sets of live loads. From the longitudinal bending moment and shear force of all 24 simulation cases, extreme locations are identified and critical buckling stress on the plates close to these locations is predicted and compared with actual axial and shear stresses on the hull plate to predict the condition at which the buckling structural failure occurs.