Use Of Finite Element Analysis Research Articles

Determination of Modified Mohr-Coulomb Damage Model Parameters for DH780 Steel in Finite Element Analysis

In sheet metal forming processes, tearing problems might be occasionally encountered due to many reasons such as incorrect forming parameters. The trial and error methods that are used to solve such problems, on many occasions, are time-consuming and inefficient in terms of finding the correct forming parameters or die design for the forming process. The finite element analysis method, on the other hand, can be used as a tool that is both time and cost-saving. However, in order to effectively exploit the use of finite element analysis in sheet metal forming operations, the material that is used to be formed needs to be well characterized in terms of its hardening behaviour and failure criteria. In this study, a TRIP-aided DP steel (DH780) has been tensile tested in three different deformation conditions (uniaxial, plane stress and shear) and the parameters of its hardening model (Hollomon) and failure criteria (Modified Mohr-Coulomb) have been determined. According to the simulation results, obtained hardening parameters are able to describe the flow behaviour of the steel and the used failure criterion is able to predict the experimental failure correctly in each deformation condition.

Understanding Traumatic Brain Injuries in Military Personnel: Investigating the Dynamic Interplay of the Cerebrospinal Fluid and Brain During Blasts.

Background It is estimated that around 450,000 traumatic brain injury cases have occurred in the 21st century with possible under-reporting. Computational simulations are increasingly used to study the pathophysiology of traumatic brain injuries among US military personnel. This approach allows for investigation without ethical concerns surrounding live subject testing. Methodology The pertinent data on head acceleration is applied to a detailed 3D model of a patient-specific head, which encompasses all significant components of the brain and its surrounding fluid. The use of finite element analysis and smoothed-particle hydrodynamics serves to replicate the interaction between these elements during discharge through simulation of their fluid-structure dynamics. Results The stress levels of the brain are assessed at varying time intervals subsequent to the explosion. The regions where there is an intersection between the skull and brain are observed, along with the predominant orientations in which displacement of the brain occurs resulting in a brain injury. Conclusions It has been determined that the cerebrospinal fluid is inadequate in preventing brain damage caused by multiple abrupt directional shifts of the head. Accordingly, additional research must be undertaken to enhance our comprehension of the injury mechanisms linked with consecutive changes in acceleration impacting the head.

Analyzing the Response of Structural Members to Impact Loads Using Finite Element Analysis: A Review

Background: The use of Finite Element Analysis (FEA) has become widespread in simulating the response of structural members subjected to impact loads. This review paper aims to provide an overview of FEA's application for predicting the response of structural members under impact loads. Objectives: The objectives of this review are to analyze the analytical and experimental methods used for studying the dynamics of vibration and impact loads, including Finite Element Analysis, Modal Analysis, Experimental Modal Analysis, Response Spectrum Analysis, and Design of Experiments Analysis. Methods: The review paper thoroughly examines the principles of FEA, the various types of impact loads, and the different structural members involved. It analyzes the definitions, causes, effects, and analytical and experimental methods used to study vibration and impact loads. Results: The review paper highlights the significance of studying these dynamics, as failure to do so can result in catastrophic failures of structures and machines. It presents a comprehensive review of the effects of vibration and impact loads on structures and machines and the advantages and limitations of different analytical and experimental methods. Conclusion: This review provides valuable insights into the dynamics of vibration and impact loads and their potential consequences on structural integrity. The findings emphasize the importance of employing appropriate analytical and experimental methods to accurately predict and assess the response of structural members under impact loads.

Design assisted by finite element analysis – Introduction to prEN 1993‐1‐14 and Technical Report

AbstractThe application of design by finite element analysis (FEA) is becoming increasingly prevalent in applied engineering; however, codified provisions remain scarce. The vision of CEN/TC 250/SC 3 was to develop a new comprehensive document based on the existing provisions currently distributed throughout the different Eurocode 3 parts, and with extension where necessary to cover all fields of structural steel design. Within the development process, two documents are being prepared: (i) the code, prEN 1993‐1‐14 and (ii) a Technical Report. The new code aims to provide rules on the use of finite element analysis and other numerical methods for verifying ultimate limit states, serviceability limit states and fatigue. In parallel, the Technical Report will provide background information and explanations of all aspects of the code, as well as benchmark cases and design examples to support the correct application of the prEN1993‐1‐14 design rules and the necessary benchmarking required for model validation. The assumed stakeholders are mainly designers who can find direct guidance for design by finite element analysis in daily engineering practice. This current paper gives an overview of the new code and accompanying Technical Report, as well as the development process and harmonisation within the current Eurocode 3 framework.

Investigations on the material behaviour of weld seams for the use in finite element analyses

AbstractThe design of complex structural steel connections by finite element analysis is common practice nowadays. However, for welded joints there are no normative regulations for the static finite‐element‐analysis. To analyse the specific material behaviour in the weld area and derive a geometry and material model for the finite element analysis, tensile tests on specimens with different weld geometries are made at the Technical University of Darmstadt. During the tests an optical measuring method, called Digital Image Correlation, is used. It records the deformations on the surface of the specimen and assigns the recorded analogue test load to the images. By this way, the load‐deformation‐behaviour in all areas of the weld can be determined. In addition to the tensile tests, microsection examinations are carried out. The applied colour etching makes the microstructure of the weld zones visible so they can be geometrically superimposed with the strain images of the tensile tests. In welded connections the stress state is very complex. Therefore, numerical investigation must be performed to derive the final stress‐strain‐curves of the weld area. These curves can then be implemented as a material model for the finite element analysis of welded connections.

Buckling Analysis of Laminated Composite Plate Using FE Method

Abstract: This study investigates the use of finite element analysis to composite plate structures. The major purpose of this research is to use FEA techniques to evaluate the buckling behavior of composite plates. FEA simulation and CAD modeling are both possible with the help of ANSYS APDL. It has been determined that carbon composite is a material and that the individual plates may take on either a hexahedral or a quadrilateral geometry. The buckling load of the plate is determined by applying the structural loads on it. The FEA is performed for all permutations, which include changing the h/b ratio from 0.08 to 0.16 and then from 0.16 to 0.24. The buckling load is determined by the eigenvalues and is different for each h/b ratio. According to FEA predictions, increasing the h/b ratio increases the buckling load. The findings of this study suggest that finite element analysis (FEA) may be utilized to enhance the design of composite structures subjected to a wide range of loading scenarios.

Univariate Gauss quadrature for structural modelling of tissues and materials with distributed fibres

This work presents a method for computing the averaged free energy and constitutive relations in hyperelastic material models with distributed fibres, as they apply to soft fibre-reinforced materials and biological tissues. While these models are currently implemented through either spherical cubature of the fibre free energy or its Taylor series, we here propose a new method based on a univariate Gauss quadrature rule with integration points and weights informed by the statistical moments of the distribution of fibre stretch. As an intrinsic property, the new approach separates the integration of the fibre constitutive law from the integration of the orientation distribution, the latter leading to structural tensors of even order. Provided the latter 2n−1 tensors are computed accurately up to tensorial order 2(2n−1), the method integrates exactly any polynomial of order 2n−1 that agrees with the fibre law at the n integration points. After formally introducing the quadrature method for generally non-affine fibre deformations and arbitrary order, we focus on the important special case of affine fibre kinematics and discuss the rules with n≤3 integration points, for which the corresponding positions and weights are determined analytically. At a computational cost comparable to the existing approaches, the new method does not require the fibre law to be analytic and can thus robustly deal with piece-wise definitions of the fibre energy, in contrast to Taylor-series approaches, and it does not induce additional anisotropy as it can occur with spherical cubature rules. The 3-point rule is further investigated and illustrated in numerical examples relating to soft collagenous tissues based on a Fortran implementation of the method suitable for use in finite element analyses.

Design and Optimization of Electromagnetic Induction Device based on Finite Element Analysis

Electromagnetic induction is the basis of most electrical and power equipment. In order to improve the overall performance of electromagnetic induction devices, it is necessary to analyze the distribution of electric and magnetic fields around and inside the devices, and guide the structural adjustment and material selection of devices. However, due to the integral and differential operations involved, complex electrical and magnetic field problems are often unable to be analyzed by analytical methods. With the improvement of numerical analysis theory and computer performance, the use of finite element analysis is expected to solve the complex electromagnetic field problems in practical applications. Using finite element analysis, the electromagnetic field distribution characteristics and influencing factors of electromagnetic induction devices of household induction cooker are studied, the corresponding mathematical model is established, the influence of electromagnetic parameters of each part of the induction heating system on heating energy efficiency is studied, and the optimization design is carried out according to different application requirements, so as to provide a basis for further improving the performance of devices.

Use of finite element analysis for the thermal gradient determination of a neutron transparent high-pressure sample environment for neutron tomography

ABSTRACT A 3D Finite Element Analysis model was developed to describe the temperature distribution inside a novel neutron transparent high-pressure sample assembly. The validity of the model was established by conducting experimental validation. The Finite Element Analysis model was utilised to evaluate the sample assembly’s temperature gradients and optimise its geometry and components. The results indicate that the discrepancy between the temperature recorded in the laboratory using thermocouples and the temperature calculated by the Finite Element Analysis model was only 4% under the assumption that the thermocouple was positioned in the middle of the sample assembly. The models further demonstrate that the Finite Element Analysis approach is a valuable tool for optimising the sample assembly by considering the impact of different materials and variations in the shape of its components.

BIO3: Advancement of a Novel Polymeric Transcatheter Aortic Valve as an Alternative to Tissue-based Valves

Background: Transcatheter aortic valve replacement (TAVR) is a minimally invasive alternative to surgical valve replacement, originally targeted to elderly patients with aortic stenosis (AS), now increasingly utilized in younger lower risk AS patients. With growth of TAVR the shortcomings of current tissue-based valves are becoming prevalent, namely limited durability and thromboembolic risk. To address these, a polymeric TAV named PolyV-2 (27 mm, PolyNova Cardiovascular Inc, Stony Brook, NY) was designed, optimized, and further tested. Methods: The design of the PolyV-2 (Figure A) was achieved with a battery of in silico simulations including the use of finite element analysis (FEA, Abaqus 2020, Dassault Systems, Providence, RI) to optimize the radial force of the stent frame and minimize leaflet stresses during the cardiac cycle. The PolyV-2 employs a sutureless design via coating the stent with polymer, bypassing problematic hand suturing manufacture of tissue valves. The PolyV-2 utilizes a thermoplastic elastomer polymeric material which was tested in vitro with accelerated wear durability testing according to ISO 5840-3 (2015) with periodic performance testing, evaluated against tissue-based surgical and TAV devices for platelet activation rate (PAR) in a pulsatile flow loop, and evaluated for calcification risk with similar wear testing in a pro-calcific medium. To assess the deposition of calcifications in the valves, both µCT and ICP spectroscopy were used. Results: The optimization process of the PolyV-2 leaflets (Figure B) was able to greatly lower the peak and mean stresses throughout over the cardiac cycle by employing a variable thickness across the entire leaflet. With success of this in silico optimization process, the leaflets were then tested in vitro (Figure C) in accelerated wear testing, performing 1Billion cycles w/o failure – correlating to 25 years of efficacy in vivo, exceeding the 250 million minimum required by the FDA. The material also demonstrated favorable hemocompatiblity as to PAR (Figure D) with activation significantly lower than a commercial tissue TAVR device, more comparable to a surgical device. The pro-calcific wear testing demonstrated no deposition of calcific salts within the polymer leaflet (µCT image, Figure E) compared to the tissue valve and minimal calcium detected with ICP spectroscopy. Conclusion: To mitigate the persistent complications of tissue-based TAV devices, the polymeric PolyV-2 valve was optimized through a battery of in silico and in vitro trials to offer superior hemodynamics, performance, and durability. Proper design and material considerations are essential to ensure successful translation, demonstration of enhanced bio/hemocompatibility and advance of the PolyV-2 through in vivo animal trials.

Evaluation of inter-maxillary fixation techniques for multi-piece Le Fort I osteotomies using finite element analysis.

A strong postoperative occlusal relationship is essential for the long-term stability of the jaw relations post orthognathic surgery. In multi-piece Le Fort I osteotomy, obtaining a satisfactory inter-maxillary fixation (IMF) of the mobilized segments in the correct position and according to the preoperative plan is difficult. Herein, we aimed to evaluate three different IMF techniques (tooth-supported, bone-supported, or hybrid IMF) usingfinite element analysis (FEA) of the occlusal surfaces of four models: three multi-piece (lateral incisor-canine, central incisor-central incisor, and canine-first premolar) and a single one-piece Le Fort I osteotomy scenario. Three different IMF techniques were applied separately to three different multi-piece models and a single one-piece Le Fort I model designed using related software. Simulation brought the lower and upper jaw models to the planned occlusion. Each model's occlusal force was applied to determine their distributions under 100 N, 300 N, and 800 N loads. Forces on the maxilla and mandible during fixation, the effect of these forces on the force distribution in the occlusion, and the accumulated stresses in these regions were determined with Algor Fempro and Rhinoceros software to determine the ideal fixation method. Data obtained were interpreted and evaluated according to the advantages and disadvantages of the actual surgical scenario. In all four models studied, the hybrid IMF technique was found to be the ideal IMF technique, followed by the teeth-and bone-supported IMF techniques. FEA allows the manipulation of single parameters, which clinical methods cannot obtain, thereby allowing each to be examined separately. Further clinical trials are required to validate these findings.

Validation of Low Cost Patient Specific Implant Design Using Finite Element Analysis (FEA) for Reconstruction of Segmental Mandibular Defects: A Case Report and Literature Review.

Mandibular continuity defects can cause functional and cosmetic deformities affecting a patient's quality of life. Reconstruction of such defects can be intricate even for the most seasoned maxillofacial surgeons. Reconstruction plates were the standard of care in the past, followed by a secondary reconstruction using autogenous grafts. Novel technological upgrades like customized computer-designed patient-specific implants (PSIs) have overtaken these stock reconstruction plates to enhance the aesthetics and address the individual clinical situation. Affirmation of the above plate design using biomechanical analysis can further improve the efficacy of PSIs. The present case report describes a novel combination of an autogenous graft and a low-cost patient-specific implant with the prosthesis design validated using finite element analysis. The authors have also reviewed the biomechanical evaluation of PSIs design and its uses in treating mandibular continuity defects. Use of FEA helped to inspect the potential weakness and stress distribution through out the implant due to this there was no sign of hardware failure.

Utilizing XFEM model to predict the flexural strength of woven fabric Kenaf FRP plate strengthened on plain concrete beam

The evolution of advancing computing technology has encouraged the use of finite element analysis to require constitutive models, mostly adopted extensive experimental datasets. Nevertheless, fewer material properties are required within the bilinear traction-separation relationship incorporated with the XFEM technique and require fewer computation efforts due to the energetic approach simulation. This study used ABAQUS CAE 2021 to predict the flexural strength of plain concrete beams strengthened with Kenaf Fibre Reinforced Polymer (KFRP) plates under a four-point bending test, later validated with experimental datasets. The varying parameters, including woven fabric architectures, lengths, widths, and plate thickness, were considered. The results demonstrated that the consistency proposed modelling technique in this study well-captured failure modes and crack development as experimental observations. All models demonstrated an increase in peak load, and a comparison of load-deflection profiles was made between the numerical FEA modelling with the experimental works. The peak load discrepancies between the numerical outputs and the experimental datasets were found to be less than 12% in all testing series. Despite promising findings, stress analysis on peel and shear stresses associated with failure modes exhibited was performed. It was found that KFRP ruptures occurred due to peel stress peak at plate mid-span, while shear mode failure demonstrates concentrated peel stress (to lesser extent shear stress) at KFRP edge tip. Hence, a more unified approach is promoted to require only two material properties (preferably independently measured values). This approach enables a designer to choose the optimum FRPs size using the current modelling tool, substantially reducing laborious and expensive experimental setup.

Advances in Finite Element Analysis of External Field‐Driven Micro/Nanorobots: A Review

With the development of nanotechnology, micro/nanorobots (MNRs) have become promising medical tools given their advantages of unconstrained and precisely controlled navigation. However, given the complexity of MNRs’ dynamic biological environments and the limitations of current experimental methods, it remains challenging to simulate the motion mechanism, functional implementation strategy, and adaptability of MNRs in dynamic environments. Finite element analysis (FEA) plays an important role in MNR research; thorough review of state‐of‐the‐art research on MNRs. FEA is used to simulate MNRs motion mechanism, and theoretical models combined with experimental results are proposed to explain the motion mechanism. FEA can reduce the error rate of experiments. Combined with the simulation results, the optimal scheme is selected for experiments, and a reliable design strategy of MNRs is obtained. FEA has become a more effective method to obtain the optimal design of MNRs for in vivo applications. Therefore, herein, the design and driving mechanism of MNRs, the different solutions proposed for complex dynamic environments, and the use of FEA in the related research are introduced by this review. The current challenges and future research directions of FEA combined with external field‐driven MNRs are summarized.

Stress Evaluation in Rails Based on Vibration Data and Artificial Intelligence

An inspection technique for the estimation of longitudinal stress and rail neutral temperature (RNT) in continuous welded rails (CWR) is presented. The technique is based on the use of finite element analysis (FEA), vibration measurements, and machine learning (ML). The FEA is used to establish the dependency of the vibration characteristics (mode shapes and frequencies) of any given CWR to the conditions of the track and the longitudinal stress of the rail. The dependency is then used to train an ML algorithm that is tested using experimental data obtained with two accelerometers bonded to the rail of interest, during a field test conducted in Colorado, U.S. A commercial finite element (FE) software was used to model the rail track as a short segment repeated indefinitely and under varying boundary conditions and stress. Three ML models were developed using hyperparameter search optimization techniques and k-fold cross-validation to infer the stress or RNT from the frequencies of vibration extracted from the time waveforms recorded by the accelerometers. The results demonstrated that the success of the technique is highly dependent on the accuracy of the FE model. The results also demonstrated that ML was mostly able to learn from the experimental data and successfully predict the neutral temperature.

Considerations of Hull Structural Deformation on Hydrodynamic Performance of Sailing Yachts

_ The increasing availability of affordable finite element modeling software and computational fluid dynamics codes have given today’s sailing yacht designers tools that, in the past, were only available to designers of yachts competing in the most high-profile events. This paper provides a case study on the structural design of the International America’s Cup Class Yacht Stars & Stripes USA-34, which won the U.S. defender series, the Citizen Cup, leading up to the 29th America’s Cup competition in 1995. The authors have recently been able to publicly share this information, and feel that the problem-solving approach is of direct use to many of today’s designers. The design approach is twofold, the first being the use of Finite Element Analysis to minimize drag-inducing local deformations. Over 80 finite element models were analyzed with varying configurations, starting with an initial baseline structure based on the previous boat, USA-11. These structural improvements reduced local hull deflection from5 to 6 mm per meter on the previous design to less than 1 mm per meter on the USA-34 design. The second part of the design approach isolates the hydrodynamic effects of global bending under rig tension. Illustrative tank tests are provided to demonstrate how the global sagging of the hull, caused by rig tension, can often increase the resistance of a yacht (especially one built for racing). As part of a series of steps taken to mitigate the effect of rig tension, a novel design was developed, with soft patches and flexible structure to permit low-cost modification of the hull in the boatyard, giving approximately a 225mm increase in waterline length and 75 mm reduction in beam if needed—a modification that was made to USA-34 prior to winning the finals of the Citizen Cup, and at a cost of under $500. The reduction of drag-inducing local hull form deformations, and the development of the cost-saving hull modification concept, demonstrate how a creative designer can take advantage of the finite element modeling tools that are now widely available.

Preliminary design of the cold mass supports for the EU DEMO feeders

The Cold Mass Support (CMS) is a basic structural component of the feeder system of the EU DEMO tokamak. The function of this structural element is not only to provide support to the containment duct – wiring the cryogenic lines, electrical bus bars and instrumentation to the magnets – in terms of both gravity loads and Lorentz forces, but also to isolate the low-temperature elements from the ambient, minimising the (conductive and radiative) heat loads. In this work, we describe a simulation and optimisation procedure adopted for the preliminary design of the EU DEMO CMS, which makes use of finite-element analyses and a shape parameterisation based on Radial Basis Functions (RBF). Structural and thermal numerical grids are morphed from a baseline configuration, and complex shape variations are achieved by means of an advanced meshless procedure based on CAD parametric surfaces, respecting the given geometrical constraints. A response surface-based optimisation is finally performed, in order to obtain a preliminary CMS candidate able to fulfil both structural and thermal targets.

Finite Element Analysis of Foldable Electric Vehicle

In the present work finite element analysis of foldable electric vehicle is carried out. With the use of finite element analysis, the magnitude of stresses and deflections at critical locations of the vehicle is evaluated. Dynamic analysis to simulate the vehicle behavior has also been carried out. The vehicle is proposed to accommodate a single passenger. The foldable vehicle is designed as per the regulations prescribed by the Automotive Resarch Association of India. Maximum vehicle speed of 25 kmph and dimensions in folded circumstances are the design constraints accounted for in the present work. Vehicle dimensions are computed using design constraints and the process mentioned in Automotive Industry Standard 049 (AIS-049). Materials for vehicle chassis, seat, hand rests, and centrally located telescopic support are steel 1018 and aluminum from speed and self-weight considerations. With the aid of the classical approach braking force, motor torque, wheel rpm, power, rolling resistance, and aerodynamic drag are calculated. Solidworks software is used for the preparation of computer-aided model. Finite element analysis of the foldable vehicle has been carried out to evaluate the static and dynamic stresses induced in the vehicle components. The meshing of the foldable vehicle is carried out using Ansys Workbench. From modal analysis, six mode shapes of the foldable vehicle are formulated, and corresponding frequencies and deflections are devised. A Mesh generator is used to mesh the foldable vehicle. The deflection and frequency magnitudes of the foldable vehicle evaluated are in good agreement with the experimental results available in the literature for similar materials.

Development and validation of risk of bias tool for the use of finite element analysis in dentistry (ROBFEAD)

There has been a systematic review of studies that used FEA in dental sciences, but no adequate risk of bias (RoB) analysis technique has been developed. Therefore, the development and validation process of RoB in studies using the finite element analysis in dentistry (ROBFEAD) tool is described. In the first phase of development, the scope of the tool and possible modifications were covered, and validation was done in the second phase. The developed tool comprised 6 domains and a total of 22 guiding questions in these domains. This article proposes the development and validation of ROBFEAD, a tool for measuring RoB in finite element research in dentistry.

Acceleration of structural topology optimization using symmetric element-by-element strategy for unstructured meshes on GPU

PurposeStructural topology optimization is computationally expensive due to the involvement of high-resolution mesh and repetitive use of finite element analysis (FEA) for computing the structural response. Since FEA consumes most of the computational time in each optimization iteration, a novel GPU-based parallel strategy for FEA is presented and applied to the large-scale structural topology optimization of 3D continuum structures.Design/methodology/approachA matrix-free solver based on preconditioned conjugate gradient (PCG) method is proposed to minimize the computational time associated with solution of linear system of equations in FEA. The proposed solver uses an innovative strategy to utilize only symmetric half of elemental stiffness matrices for implementation of the element-by-element matrix-free solver on GPU.FindingsUsing solid isotropic material with penalization (SIMP) method, the proposed matrix-free solver is tested over three 3D structural optimization problems that are discretized using all hexahedral structured and unstructured meshes. Results show that the proposed strategy demonstrates 3.1× –3.3× speedup for the FEA solver stage and overall speedup of 2.9× –3.3× over the standard element-by-element strategy on the GPU. Moreover, the proposed strategy requires almost 1.8× less GPU memory than the standard element-by-element strategy.Originality/valueThe proposed GPU-based matrix-free element-by-element solver takes a more general approach to the symmetry concept than previous works. It stores only symmetric half of the elemental matrices in memory and performs matrix-free sparse matrix-vector multiplication (SpMV) without any inter-thread communication. A customized data storage format is also proposed to store and access only symmetric half of elemental stiffness matrices for coalesced read and write operations on GPU over the unstructured mesh.