Finite Element Analysis Techniques Research Articles

Predictive modeling of wide-shallow RC beams shear strength considering stirrups effect using (FEM-ML) approach

This paper presents an analysis and prediction of the shear strength of wide-shallow reinforced concrete beams, utilizing Finite Element Analysis (FEA) and machine learning techniques. The methodology involves validating a detailed Finite Element Model (FEM) against experimental results, conducting a parametric study, and developing three Machine Learning prediction equations. The FEM captures concrete and steel behaviors, including cracking and crushing for concrete and linear isotropic properties for steel reinforcement. Loading and boundary conditions are defined for accuracy and validated against 13 experimental specimens, exhibiting a maximum 8% and 12% difference in loads and deflections, respectively. A parametric study generates a dataset of 77 wide beam configurations, exploring variations in beam widths, concrete strengths, compression rebars, and shear reinforcement. This dataset is used to develop machine learning models, including “Genetic Programming (GP)”, “Evolutionary Polynomial Regression (EPR)”, and “Artificial Neural Network (ANN)”. Comparative analysis reveals GP and EPR models with over 95% correlation, while the ANN model outperforms with 99% accuracy. Sensitivity analysis underscores the significant influence of concrete strength and beam aspect ratio on shear strength. In conclusion, the study demonstrates the potential of FEA and machine learning models to predict shear strength in wide-shallow reinforced concrete beams, providing valuable insights for architectural design and engineering practices and emphasizing the role of concrete strength and beam geometry in shear behavior.

A comparative analysis of 3D woven honeycomb-based aircrew helmet liners against Nomex and Aluminum alternatives

This study investigates the energy dissipation efficiency of an aircrew helmet liner developed using 3D woven honeycomb structural composites compared to different commercially available honeycomb liner materials such as Nomex, and Aluminium. In contrast to liners with discrete density differences, the use of a honeycomb-based liner reduces the concern about delamination, back face deformation and fracture propagation. The research involves comparing several parameters related to crashworthiness, such as specific energy absorption (SEA), crush force efficiency (CFE), and margin of safety, which are crucial for head protection and ensuring helmet injury tolerance. These parameters play a vital role in assessing the ability of different configurations of the honeycomb liner during impacts. Flatwise compression and dynamic impact tests were conducted to evaluate the helmet liner’s performance while maintaining consistency in the helmet shell component. Finite element analysis (FEA) and 3D x-ray Tomography techniques were utilized to analyse the back face deformation (BFD) at high-velocity impact and the internal damage resulting from impacts on the helmet liners, respectively. The results revealed that the 3D woven honeycomb liner configuration performs optimally in terms of energy absorption by demonstrating sufficient and balanced competency across these three critical factors. Additionally, the simulation result revealed that the 3D woven honeycomb liner exhibits wave propagation. This phenomenon enhances its energy absorption capacity and reduces back-face deformation attributed to its crushing behaviour. This research offers valuable insights for improving the performance of aircrew helmet liners, with a particular focus on utilizing 3D woven honeycomb liners featuring 3D woven solid structure to maintain exceptional structural integrity.

Investigating Material Performance in Artificial Ankle Joints: A Biomechanical Study

This study delves into an in-depth examination of the biomechanical characteristics of various materials commonly utilized in the fabrication of artificial ankle joints. Specifically, this research focuses on the design of an ankle joint resembling the salto-talaris type, aiming to comprehensively understand its performance under different loading conditions. Employing advanced finite element analysis techniques, this investigation rigorously evaluates the stresses and displacements experienced by the designed ankle joint when subjected to varying loads. Furthermore, this study endeavors to identify the vibrating frequencies associated with these displacements, offering valuable insights into the dynamic behavior of the ankle joint. Notably, the analysis extends to studying random frequencies across three axes of motion, enabling a comprehensive assessment of directional deformities that may arise during joint function. To validate the effectiveness of the proposed design, a comparative analysis is conducted against the star ankle design, a widely recognized benchmark in ankle joint prosthetics. This comparative approach serves dual purposes: confirming the accuracy of the findings derived from the salto-talaris design and elucidating the relative efficacy of the proposed design in practical application scenarios.

Finite Element Analysis of Manufacturing Deformation in Polymer Matrix Composites.

This paper introduces a unique finite element analysis (FEA) technique designed to predict elastic response in polymer matrix composites (PMCs). Extensive research has been conducted to model the manufacturing process of multiple 'L'-shaped components, fabricated from SPRINTTM materials (GLP 43 and GLP 96) at two thicknesses (15 mm and 25 mm). Three distinct FEA methodologies were utilised to determine the impact of thermal loads and rigid fixtures. An error deviation of 3.23% was recorded when comparing simulation results to experimental data, thereby validating the effectiveness of the FEA methodology.

Groove design optimization of femoral heads in solid hip implants: Study on stress distribution and total deformation using FEA and full factorial design

Hip replacement surgery is a common procedure that relies on the implant's design to withstand daily activities. This study aims to investigate the impact of different surface groove designs on the performance of solid hip implants using finite element analysis (FEA) and optimization techniques. The study evaluates the influence of grooves on the stress distribution and total deformation of the implant, considering three designs: no grooves, horizontal grooves, and vertical grooves on the surface of the femoral head. The simulations were conducted using Ansys Mechanical, and the optimization process was carried out using the general full factorial design method in Minitab software. The results demonstrate that the groove design significantly affects the stress distribution and wear of the implant. The vertical groove design shows better overall results, indicating the best performance. The study also evaluated the influence of force on the performance of the implant, with different load range. The optimization process using the general full factorial design method revealed that the optimal groove design was a vertical model with an optimized groove depth and width. These findings offer valuable insights into the impact of surface groove designs on the performance of solid hip implants, leading to better patient outcomes and longer implant lifespan. Overall, this study provides a comprehensive understanding of the effect of surface groove design on the performance of solid hip implants.

On elastoplastic behavior of porous enamel–An indentation and numerical study

The micro/nano pores in natural mineralized tissues can, to a certain extent, affect their responses to mechanical loading but are generally ignored in existing indentation analysis. In this study, we first examined the void volume fraction of sound and caries lesion enamels through micro-computed tomography (micro-CT). A Berkovich indentation study was then carried out to characterize the effect of porous microstructure on the mechanical behavior of the human enamels. The indentation tests were also modeled using the nonlinear finite element analysis technique to simulate indentation load-displacement curves, which showed reasonable agreement with the experimental measurements. From the simulation results, the extent of densification in the plastic zone was identified and the corresponding stress and contact pressure evolutions were quantified. Further, a conventional elastic-perfectly plastic material model without considering micropores was also developed to investigate the compaction effect of the porous structure. The simulation results reveal that conventional elastic perfect-plastic constitutive models become less reliable to model the mechanical behavior of carious lesion enamel with increasing loss of mineral content as it underestimates the yield stress and plastic energy dissipation. This study divulges the importance of compaction of porous enamel structure beneath the indented area. Note that understanding the effect of porous microstructures on plastic behavior is vital as the involved inelastic deformation mechanism associated with irreversible processes, such as wear and localized microcracking, has a significant bearing on wear and fatigue behavior of enamel. Statement of significanceBased on micro-CT and nano-indentation characterization, a numerical model was developed aiming to precisely describe the deformation behavior of naturally porous enamel. Inelastic properties and energy dissipation characteristics of porous enamel were investigated in detail. This work demonstrated that the existence of micro-pores in White Spot Lesions (WSLs) contributes to mechanical stability, which can mitigate the reduction in Young's modulus and fracture toughness resulting from loss of mineral components. The knowledge gained from this study can be used to explain the mechanisms related to irreversible processes, such as contact induced cracking and wear, and strengthen understanding of the mechanical behavior of porous mineralized tissues.

Assessment of Buckling Failure in Oil Storage Tanks: Finite Element Simulation of Combined Internal and External Pressure Scenarios

Investigating the structural behaviour and buckling susceptibility of cylindrical oil storage tanks is crucial for ensuring their safe and reliable operation. In this study, the structural behaviour and buckling susceptibility of closed roof-top cylindrical oil storage tanks under combined internal and external pressure scenarios were investigated using the finite element analysis (FEA) technique. By utilizing the FEA technique, the combined effect of wind-induced pressure of 250 Pa, applied on the outer surface of the tank and internal pressure of 0.5 MPa, applied on the outer surface of the storage was analysed. The result reveals significant stress concentrations and deformation patterns, particularly on the windward side of the tank, thus, emphasizing the susceptibility of the storage tank to buckling under the specified operating conditions for both the filled and half-filled tank; with internal pressure emerging as the primary contributor to mechanical strain and deformation experienced in the tank, while the wind load plays a secondary but significant role in the deformation of the tank. The fe-safe predicted useful life shows that under the specified operating conditions, the filled storage tank will survive 1 429 hours (2 months) while the half-filled tank will survive 3 551 hours (5 months) before failure due to buckling. Thus, the useful life estimation results show the importance of varying oil levels and operating conditions in the structural assessments of storage tanks.

Finite element stress analysis and topological optimization of a commercial aircraft seat structure

In recent years, the Finite Element Method (FEM) has emerged as a cornerstone in the field of seating design, particularly within the aircraft industry. Over the past decade, significant advancements in Finite Element (FE) analysis techniques have revolutionized the seat industry, enabling the creation of safer and more cost-effective seat designs. The accuracy of FE analysis plays a pivotal role in this transformation. In the process of constructing a reliable finite element model, the selection and precise manipulation of key parameters are paramount. These crucial parameters encompass element size, time scale, analysis type, and material model. Properly defining and implementing these parameters ensures that the FE model produces accurate results, closely mirroring real-world performance. Verification of Finite Element Analysis (FEA) results is commonly accomplished through experimental methods. Notably, when the parameters are appropriately integrated into the modelling process, FE analysis outcomes closely align with experimental results. This study aims to leverage the power of FEM in performing static stress analysis and topology optimization of aircraft seats using the SOLIDWORKS commercial finite element platform. By simulating loading conditions, this research calculates static stresses and displacements experienced by the aircraft seat. Through a comprehensive topology optimization study, the weight of the airplane seat is remarkably reduced by up to 30%, while still prioritizing passenger safety. The success of this optimization showcases the potential for substantial weight savings in aircraft seat design without compromising safety standards.

Thermal analysis of 4-phase 8/6 SRM for EV application

This article provides a comprehensive analysis of the thermal characteristics of a 4-phase 8/6 switching reluctance motor (SRM) designed for use in an e-rickshaw (3-wheeler) application. The determination of core and copper losses is achieved through electromagnetic analysis using Finite Element Analysis (FEA). The analysis is conducted via MOTORCAD, a multiphysics design software. This work includes the examination of both static and transient temperature conditions. Static analysis entails the estimation of losses by taking into account the motor's maximum current and operating the motor under steady-state conditions. Transient analysis involves the examination of two separate scenarios. One possesses a simple transient characteristic, while the other possesses a distinct duty cycle. The losses obtained from the electromagnetic analysis are used as the input for the simple transient thermal analysis. During transient analysis involving the duty cycle, losses are assigned to certain operating conditions, such as changes in the operating speed of the motor. This study employs the Lumped Parameter Thermal Network (LPTN), as well as 3D and 2D FEA techniques to conduct thermal analysis. The findings were compared and subsequently given in the article. The findings produced from the LPTN and 3D FEA approaches demonstrate a strong correlation. The motor's maximum temperature is limited to 180 °C. The findings indicate that the highest temperature, both under static and transient conditions, is below the maximum attainable value.

Comparative Analysis of Transmission Housings to Evaluate Whining Noise Performance

A quite cabin is always a preferred choice of the customer. Powertrain acts as a source for many noise and vibration problems in a passenger car. Transmission plays a major role in modulating the power from engine to the drive train and is exposed to a high vibration and noise environments. Hence design of transmission for low vibration & noise is need of the hour. This paper attempts to perform a comparative study of 6 housings of different design of a two-wheel drive passenger car to evaluate the vibration performance and Noise radiation characteristics by using FEM (Finite Element Method) & BEM (Boundary Element Method) & finite element analysis techniques. The authors also try to put forward a layout comparison study for the housings and conclude what design is best suited for better NVH whine performance in view of vibrations & sound radiation. These indicative results from this paper can be referred by the design & analysis engineers during early product development of the transmission.
 Keywords: Transmission, Housings, Whining Noise, Bionic Design, NVH Analysis, Durability Analysis, Study of Housings, Housings NVH Analysis

Wheel-rail impact load due to the loss of sleeper-ballast interface

This paper presents a comprehensive study on the simulation and analysis of the loss of sleeper-ballast interfaces in railway systems. Through a combination of Multibody Dynamics (MBD) and Finite Element Analysis (FEA) techniques, accurate modeling and validation processes were employed to investigate the impact of interface loss on wheel-rail impact load. Various scenarios were explored, revealing significant findings: for fewer than 4 sleeper-ballast interface losses, a notable 30% increase in wheel-rail impact load was observed, while the rate of increase in wheel-rail impact load diminished for more than 4 sleepers. Furthermore, gap size emerged as a critical factor, with sizes between 0.2 mm and 1.6 mm leading to a load increase exceeding 65%. The study also highlighted the substantial influence of train speed on load dynamics, particularly evident at speeds up to 200 km/h, where loads escalated significantly, resulting in a 180% increase under adverse conditions. These findings emphasize the importance of considering various factors in maintaining railway infrastructure integrity and safety.

Simplified homogenization technique for nonlinear finite element analysis of in-plane loaded masonry walls

The present investigation focuses on the nonlinear modelling of masonry walls under in-plane loading. To conduct this macro-scale study, a homogenization technique is applied to derive the equivalent secant moduli according to damage and friction sliding at the micro scale level for both bed mortar joint and brick material constituents. In the homogenization process the representative unit cell of masonry panel with a regular arrangement is first defined. Then a simplified kinematical model is proposed to describe the behaviour of the homogenized unit-cell under combined axial and shear stresses. This is based on the cohesive model for pure mode I and II and by allowing for the Coulomb's friction law for bed joint and the scalar damage model is adopted for the brick material. In the first stage, the proposed homogenization technique is verified for various unit cell constituents at micro-scale level. In the second step, this homogenization procedure was incorporated into proposed in-house finite elements software. To achieve this end, a new beam finite element is formulated in the context of the fibre higher order shear deformation theory HSDT. Using the proposed finite elements model, a numerical investigation is conducted to check the validity of the proposed model against the available experimental and numerical investigations. This allowed for the study of the effect of the applied compressive load on the lateral ultimate load.

Enhancing Bone Implants: Magnesium-Doped Hydroxyapatite for Stronger, Bioactive, and Biocompatible Applications.

Hydroxyapatite (HAp) with the chemical formula Ca10(PO4)6(OH)2 is an inorganic material that exhibits morphology and composition similar to those of human bone tissues, making it highly desirable for bone regeneration applications. As one of the most biocompatible materials currently in use, HAp has undergone numerous attempts to enhance its mechanical strength. This research focuses on investigating the influence of magnesium (Mg) incorporation on the structural and mechanical properties of synthesized magnesium-doped hydroxyapatite (MgHAp) samples. Apart from its biocompatibility, Mg possesses a density and elasticity comparable to those of human bone. Therefore, incorporating Mg into HAp can be pivotal for improving bone formation. Previous studies have not extensively explored the structural changes induced by Mg substitution in HAp, which motivated us to revisit this issue. Hydrothermal synthesis technique was used to synthesize MgHAp samples with varying molar concentrations (x = 0, 0.5, 1.0, and 1.5). Theoretical simulation of HAp and MgHAp for obtaining 3D structures has been done, and theoretical X-ray diffraction (XRD) data have been compared with the experimental XRD data. Rietveld analysis revealed the alteration and deviation of lattice parameters with an increase in the Mg content, which ultimately affect the structure as well the mechanical properties of prepared samples. The findings revealed an increase in compressive stress and fracture toughness as the Mg concentration in the composition increased. Furthermore, using a finite-element analysis technique and modeling of the mechanical testing data, the von Mises stress distribution and Young's modulus values were calculated, demonstrating the similarity of the prepared samples to human cortical bone. Biocompatibility assessments using NIH-3T3 fibroblast cells confirmed the biocompatible and bioactive nature of the synthesized samples. MgHAp exhibits great potential for biomedical applications in the dental, orthopedic, and tissue engineering research fields.

Enhancing fire‐resistant design of reinforced concrete beams by investigating the influence of reliability‐based analysis

AbstractA depth investigation into the impact of high temperatures on the load‐bearing capacity of reinforced concrete beams in the case of probabilistic design is presented in this paper, employing advanced finite element analysis techniques. This study addresses a critical knowledge gap in the design of fire‐resistant concrete structures, with specific emphasis on the function of concrete cover. The research aims to enhance the overall safety and reliability of concrete buildings under high temperature conditions by providing valuable insights into the behavior of reinforced concrete beams under thermal loading. The analysis incorporates reliability‐based modeling to account for uncertainties in temperature distribution within the beams. A validated finite element model is employed to simulate the performance of reinforced concrete beams at elevated temperatures. By considering various concrete cover thicknesses and heat distribution scenarios, the influence of these factors on the load‐bearing capacity is thoroughly examined. The results underscore the importance of augmenting the concrete cover to enhance the load‐carrying capacity of the beams. Furthermore, the study examines the impact of temperature distribution uncertainties, unveiling diverse load capacities associated with different configurations of concrete cover.

Numerical Simulation and Influence of Non-Gaussian Vibrations on Flexible Robotic Systems

Random vibration excitation is a standard method for obtaining the dynamic properties of aerospace structures and simulating loading conditions. Shaker-based random excitation and traditional finite element analysis techniques use random vibrations, assuming a Gaussian distribution of excitation impulse magnitudes. While Gaussian signals may sufficiently describe some vibrational environments, many real-world excitations have non-Gaussian distributions. These signals may contain vibrational impulses larger than those observed in a Gaussian signal and could cause damage if not considered. This paper examines the influence of non-Gaussian signals on flexible vs. rigid robotic architectures using NASA JPL’s Pop-Up Flat Folding Explorer Robot (PUFFER) and Cooperative Autonomous Distributed Robotic Explorer (CADRE). The results indicate that flexible systems can be significantly impacted by a non-Gaussian excitation profile and that neither a typical enveloping of a Gaussian excitation nor a superposition of the responses to a worst-case impulse load with the response to a Gaussian signal was sufficient to bound the response due to non-Gaussian excitation. The driving mechanism for increased sensitivity of flexible robotic systems appears to be inertial, and designers may consider shifting the relative flexibility of the system or its constraints to force particular deformation modes or designing hinge mechanisms with increased damping to minimize the influence of non-Gaussian signals on the response of a flexible robotic structure.

A Finite Element Modeling Approach for Analyzing the Cyclic Behavior of RC Frames

AbstractNumerous approaches and inputs for nonlinear finite element analysis used for modeling reinforced concrete systems under cyclic loads have been outlined. Practitioners usually take into account a number of significant factors when modeling, for example deciding upon the constitutive relations, the connection among concrete and steel reinforcement, and the mesh sensitivities, in order to accurately simulate the nonlinear response of reinforced concrete under cyclic loads. Therefore, it is essential to thoroughly assess popular modeling approaches and develop a reliable modeling approach with reliability, stability, and consistency. A modeling technique and practical guidelines for nonlinear finite element analysis of reinforced concrete frames subjected to cyclic loading are described in this study, taking into account the influence of parameters such as dilation angle, stiffness recovery, friction coefficient, and mesh sizes. The hysteretic force–displacement behavior and load-carrying capacity of reinforced concrete frames subjected to cyclic loading have been compared using numerical and experimental curves. Discrete fracture paths are specified in the model’s geometry to achieve an accurate depiction of the stress distribution and an adequate fit of the hysteretic behavior. The proposed modeling approach provides a precise representation of the stress distribution and hysteretic behavior while keeping computational costs reasonable.

Symmetric laminates for enhanced tire durability: A numerical study on belt edge separation

Tire failure due to belt edge separation is a common issue caused by various factors such as adhesion loss, high heat generation, and interlaminar shear. This research paper focuses on studying the phenomenon of belt edge separation in tires by investigating the effect of belt lay arrangement on this failure mode. The study examines two types of belt arrangements, namely Symmetric and Asymmetric, in both four belt and three belt package configurations, using advanced finite element analysis (FEA) techniques. MSC-MARC commercial Finite Element software is employed to conduct FE analysis on an 11R22.5 tire model under steady-state rolling conditions. Through numerical simulations, the study reveals that the symmetric belt arrangement, irrespective of the belt package configuration (four belt or three belt), minimizes strain energy density, principal strains, and principal stresses in the belt edge region compared to the asymmetric arrangement. Interestingly, the asymmetric arrangement is commonly used by tire companies for Truck Bus Radial (TBR) tires. Based on the findings of numerical simulations, this research paper proposes a new three belt package configuration that effectively utilizes the symmetric belt lay arrangement as a potential solution to reduce belt edge separation in TBR tires.

Design, Analysis, and Optimization of Off-Highway Rear Dump Truck Chassis Frame Rail Profile Using Design Exploration and Finite Element Analysis Technique

<div>During mining material hauling, the chassis frame structure of rear dump trucks is subjected to fatigue loading due to uneven road conditions. This loading often leads to crack propagation in the frame rails, necessitating the determination of stresses in the critical zone during the design stage to ensure structural integrity. In this study, a computer-aided engineering (CAE) methodology is employed to size and select the rectangular profile cross section of the chassis frame rail. A detailed design investigation of the chassis frame is conducted to assess its load resistance, structural flexibility, and weld joint fatigue life under critical stresses arising from combined bending and torsion loads. The optimization process aims to determine the optimal rail size and material thickness, striking a balance between minimizing mass and maximizing structural reliability. By achieving this, the risk of major structural failures during the transportation of large payloads can be significantly reduced. To address the demand for extended structural life and reduced chassis frame weight, the frame rail cross section is optimized using a multi-objective genetic algorithm (MOGA) implemented within the ANSYS software package. This optimization process is facilitated by utilizing design exploration studies and finite element analysis (FEA) techniques to understand how stress affects the chassis frame of a vehicle when it is subjected to combined bending and torsion load case. To do this, the research study used a combination of analytical calculations, mathematical modeling, and design exploration studies.</div> <div>The research findings highlight the effectiveness of combining empirical approaches with modern CAE tools, enabling engineers to design and analyze complex structures with optimized sizes and weights suitable for off-highway mining applications.</div> <div>Through the utilization of this integrated approach, significant advancements can be made in enhancing the structural performance and efficiency of chassis frame structures in the demanding off-highway mining industry.</div>

Gravity unloading of a very large spaceborne monolithic SiC mirror.

We formulated a gravity unloading strategy for a monolithic silicon carbide (SiC) mirror with a Φ3m aperture in space. Employing the finite element analysis (FEA) technique, a rapid solution analytical approach for determining optimal support forces during gravity unloading is introduced. This method demonstrates enhanced efficiency and accuracy compared to conventional approaches. A quantitative evaluation methodology for the gravity release error, grounded in the minimum-energy mode, is delineated. The adverse impacts could be expeditiously computed by assessing the maximum deflection of minimum-energy modes generated by various errors. The analytical findings revealed that compliance with the stipulated gravity release error criterion of less than 6 nm (root-mean-square) necessitated the gravity unloading force error to fall within the range of ±0.1N. Additionally, the gravity unloading support position error was required to be within Φ0.5m m, and the measurement error pertaining to the rib thickness of the actual mirror blank had to be within ±0.02m m.

Simulation of Design Optimization and Performance of CoCrMo Acetabular Hip Prosthesis Implants on Climbing Stairs Activity Using Finite Element Method

Damage or a loss of strength in this hip joint can occur as a result of calcification, aging, the development of illnesses such as osteoporosis, arthritis, and bone cancer, and it can also be permanently destroyed by accidents. As a result, an artificial hip prosthesis can be implanted to prevent undesirable outcomes. Throughout the jumping, running, and walking cycles, the hip joint is the most essential load-bearing and shock-absorbing component in the lower half body. As a result, using a finite element analysis technique, this work simulates the design of an Artificial Hip Joint with holes and thickness as variables, using CoCrMo acetabular implant material. ANSYS 19.1 software with transient structural characteristics will be used to simulate providing the load with the activity of climbing stairs. According to the findings of this study, the acetabular design with a thickness of 3 mm and 5 holes is the most optimal. This is due to the design's distribution of stress, strain, and total deformation being the most ideal and having a relatively low weight with appropriate usage period and safety factor forecasts.