Finite Element Analysis Research Articles

Mitigating Low-Speed Crawling and Jitter in Telescopic Hydraulic Cylinders through Stick-Slip Dynamics Analysis and Friction Reduction Strategies

Abstract This study investigates the mechanisms of jittering in telescopic cylinders and proposes effective mitigation strategies. The focus is on the dynamic behavior of hydraulic cylinders under low-speed conditions, particularly the stick-slip phenomenon. Through finite element analysis using Abaqus and tribological tests, the impact of various factors on the friction and wear properties of cylinder components is examined. Findings reveal that optimizing the average friction coefficient, stick-slip amplitude, and stick-slip time can significantly reduce jitter and creep in hydraulic cylinders. The results provide valuable insights for improving the performance and longevity of hydraulic systems in engineering machinery.

Ultimate Bearing Capacity of Bored Piles Determined Using Finite Element Analysis and Cubic Regression

Ultimate Bearing Capacity of Bored Piles Determined Using Finite Element Analysis and Cubic Regression

Developing a Virtual Model of the Rhesus Macaque Inner Ear

A virtual model of the rhesus macaque inner ear was created in the present study. Rhesus macaques have been valuable in cochlear research; however, their high cost prompts a need for alternative methods. Finite Element (FE) analysis offers a promising solution by enabling detailed simulations of the inner ear. This study employs FE analysis to create a virtual model of the rhesus macaque’s inner ear, reconstructed from MRI scans, to explore how cochlear implants (CIs) impact residual hearing loss. Harmonic-acoustic simulations of sound wave transmission indicate that CIs have minor effects on the displacement of the basilar membrane and thus minimally impact residual hearing loss post-implantation, but stiffening of the round window membrane worsens this effect. While the rhesus macaque FE model presented in this study shows some promise, its potential applications will require further validation through additional simulations and experimental studies.

Seismic Design of Underground Structures’ Vulnerability – Review.

This article examines the vulnerability of underground structures to seismic activity, with a particular focus on design and mitigation strategies. Underground buildings are essential to the development of modern infrastructure and must include tunnels, subway stations, and storage facilities. Because of its deep location, seismic design and earthquake performance are both more challenging. In this study of seismic susceptibility, topics such as ground motion characterization, soil-structure interaction, structural reaction, and failure mechanisms specific to underground structures are discussed. According to the paper, their susceptibility can be affected by geotechnical conditions, the kind of structures they have, and the construction methods that are used. The seismic stability design and analysis process involves measuring the dynamic response of subsurface structures to seismic loads. The goal is to keep earthquake and seismic forces from toppling structures in any way that is possible. Advanced analytical and numerical approaches are used in seismic stability design. Some examples of these methods are finite element analysis (FEA), discrete element modeling (DEM), and the boundary element method (BEM). In addition to that, it investigates contemporary methodologies for assessing seismic vulnerability as well as international design standards. In addition, seismic retrofitting and design advances for underground structures are analyzed and discussed in this paper. This document compiles and evaluates previous research to gain an understanding of the seismic susceptibility of subsurface structures and to promote more seismic engineering research on this extremely important topic.

Numerical Study of the Nonlinear Soil–Pile–Structure Interaction Effects on the Lateral Response of Marine Jetties

This study presents three-dimensional finite element analyses of two marine structures subjected to lateral loading to approximate environmental forces (e.g., wind, waves, currents, earthquakes). The first structure is a marine jetty supported by twenty-four piles, representative of an existing structure in Cyprus, while the second is a simplified four-pile marine structure. Soil–pile interaction is modelled using nonlinear p-y, τ-z, and q-z springs that are distributed along the piles, while steel plasticity is also considered. This study examines the relationship between failure modes, deformation modes, and plastic hinge locations with soil behaviour and soil reaction forces. It also aims at investigating the behaviour of the above structures in lateral loading and quantifying the consequences of unrealistic assumptions such as soil and steel linearity or tension-resistant q-z springs. The results indicate that such assumptions can lead to the wrong prediction of failure modes, plastic hinges, and critical elements while emphasising the crucial role of soil nonlinearity and axial pile–soil behaviour on the structural response. It is demonstrated that the dominant nonlinear sources relevant to this study, whether soil nonlinearity, plastic hinge formation, or a combination of the two, are primarily influenced by the axial capacity of soil–pile foundation systems, particularly their tensile component.

Computational integration and experimental validation of a two-length scale model for accurate prediction of steels’ plastic behavior during phase transformation

Transformation plasticity, essential during solid–solid phase transitions, significantly impacts industrial processes like welding and quenching. Accurately simulating these procedures necessitates understanding thermal, metallurgical, and mechanical effects. Leblond et al.’s model offers a foundation, but refinement for mixed isotropic/kinematic hardening is crucial. We enhance this model by introducing characteristic length scales through nonlocal variables, illuminating plastic deformation mechanisms in both phases. Our work includes numerical implementation within a finite element analysis framework and practical applications to phase transformation scenarios involving A.508 cl. 3 and A533 low-alloy steels. Results affirm model robustness and efficiency in predicting phase transformation phenomena, benefiting industrial applications.

A chronological catalog of methods and solutions in the Space–Time Computational Flow Analysis: I. Finite element analysis

AbstractThe Space–Time Computational Flow Analysis (STCFA) started in 1990 with the inception of the Deforming-Spatial-Domain/Stabilized Space–Time (DSD/SST) method. The DSD/SST was introduced as a moving-mesh method for flows with moving boundaries and interfaces, which is a wide class of problems that includes fluid–particle interactions, fluid–structure interactions (FSI), and free-surface and multi-fluid flows. The first 3D computations were reported in 1992. The original DSD/SST method is now called “ST-SUPS,” reflecting its stabilization components. As the STCFA evolved, advanced mesh moving methods, FSI coupling methods, and problem-class-specific methods were introduced to increase its scope and the ST Variational Multiscale was introduced to upgrade its stabilization components to the VMS. Complementary general-purpose methods developed in the evolution of the STCFA include the ST Isogeometric Analysis (ST-IGA) and the ST Slip Interface (ST-SI) and ST Topology Change (ST-TC) methods. The ST-IGA delivers superior accuracy through IGA basis functions not only in space but also in time. The ST-SI enables high-fidelity moving-mesh computations even over meshes made of patches with nonmatching meshes at the interfaces between those patches. The ST-TC enables high-fidelity moving-mesh computations even in the presence of topology changes in the fluid mechanics domain, such as an actual contact between moving solid surfaces. The STCFA brought first-of-its-kind solutions in many classes of problems, ranging from fluid–particle interactions in particle-laden flows to FSI in parachute aerodynamics, flapping-wing aerodynamics of an actual locust to ventricle-valve-aorta flow analysis to car and tire aerodynamics with near-actual geometries, road contact, and tire deformation. With the success we see in so many classes of problems, we can conclude that the STCFA has reached a level of remarkable sophistication, scope, and practical value. We present a chronological catalog of the methods and solutions in the STCFA. In Part I of this two-part article, we focus on the methods and solutions in finite element analysis.

Biomechanical effects of FNS on femoral neck fractures based on different reduction quality: finite element analysis.

The femoral neck system (FNS) has been extensively studied and applied for the treatment of young patients with femoral neck fractures. The purpose of this study was to explore the biomechanical impact variations in reduction qualities on femoral neck fractures, considering factors such as tip-apex distance, the positioning of the bolt in the cortical corridor of the femoral neck, and bone mineral density. A randomly selected volunteer was recruited, whose clinical data on the femur were collected to establish finite element models for positive reduction, anatomical reduction, and negative reduction respectively. Based on the constructed models, different scenarios were established by varying the tip-apex distance, bone mineral density, and positioning of the bolt in the cortical corridor of the femoral neck. Under a vertical load of 2100N, the displacement and Von Mises stress (VMS) distribution of each group of models were evaluated through simulation testing. Under a load of 2100N, the maximum VMS values of the femoral neck system and femoral head was recorded during negative reduction, 968.85MPa and 80.09MPa respectively. In addition, factors influencing the negative reduction of FNS and the femoral head were identified to be the tip-apex distance > 10mm, the presence of osteoporosis, and the bolt positioned in the lower-middle to the third part of the cortical corridor of the femoral neck. The displacement and stress of negative reduction were greater than those of positive reduction and anatomical reduction when the tip-apex distance > 10mm, and the bolt was situated in the lower-middle to the third part of the cortical corridor of the femoral neck, and in the presence of osteoporosis. This means that we recommend positive repositioning over negative repositioning when anatomical repositioning is not clinically feasible.

Effects of structural parameters on the load distribution unevenness in CFRP hybrid bonded‐bolted joint

AbstractCarbon Fiber Reinforced Polymer (CFRP) Hybrid Bonded/Bolted (HBB) joint structures are distinguished for their superior jointing performance among current mechanical joint systems, making them a favored option for mechanical joints. These structures are characterized by many structural parameters, with the relationship between these parameters and jointing performance being notably complex. Additionally, the laminate's brittleness and the uneven distribution of bolt loads in multi‐bolt joint structures impair the overall jointing performance. To investigate the impact of structural parameters on the uneven load distribution within CFRP HBB joint structures and improve their jointing performance, a finite element analysis (FEA) model grounded in 3D Hashin failure criterion is developed. Validation of the model with experimental data confirmed the uneven load distribution among bolts in multi‐bolt joints. The study elucidated the influence of changes in structural parameters (overlap length, bolt‐hole spacing, and clearance fit) on the uneven load distribution and the connection strength of CFRP HBB joint structures. A negative correlation is found between the unevenness of load distribution and connection strength, offering insights for enhancing and researching connection strength in CFRP HBB joint structures.Highlights Developed a FEA model based on the 3D Hashin failure criterion for CFRP Bonded‐Bolted joints. Identified key factors affecting HBB joint load distribution and jointing performance. Evaluated the impact of overlap length, bolt‐hole spacing, and clearance fit on CFRP joints. Suggested design optimizations for enhancing the performance of HBB joints.

Vehicle Collision Analysis of the Reinforced Concrete Barriers Installed on Bridges Using Node-Independent Model

This paper focuses on improving vehicle collision simulations using finite element analysis (FEA) to examine interactions between reinforced concrete barriers and bridge decks. Three scenarios are explored: treating the barrier as a rigid body, analyzing reinforcement with a fixed base, and including the bridge deck’s cantilever portion beneath the barrier. Except for the rigid body model, a node-independent approach models the complex interactions between reinforcement and concrete in barriers on the bridge deck. This study evaluates barrier strength, occupant risk, and post-collision vehicle safety. Strength is assessed by examining stress in reinforcement and concrete, while occupant risk is measured using Theoretical Head Impact Velocity (THIV) and Post-impact Head Deceleration (PHD). Vehicle trajectory during collisions is also analyzed for stability. The results show significant differences in stress distribution and failure patterns when the bridge deck is considered compared to scenarios without it. Occupant risk evaluations suggest more flexible responses when the bridge deck is included. However, vehicle trajectory post-collision showed no significant differences across scenarios. These findings indicate that modeling efficiency varies based on evaluation criteria, suggesting a more realistic and effective approach for assessing barriers on bridges.

Residual Stress Homogenization of Hybrid Implants

Objectives: Hybrid implants commonly exhibit decreased corrosion resistance and fatigue due to differences in compressive residual stresses between the smooth and rough surfaces. The main objective of this study was to investigate the influence of an annealing heat treatment to reduce the residual stresses in hybrid implants. Methodology: Commercially pure titanium (CpTi) bars were heat-treated at 800 °C and different annealing times. Optical microscopy was used to analyze the resulting grain growth kinetics. Diffractometry was used to measure residual stress after heat treatment, corrosion resistance by open circuit potential (EOCP), corrosion potentials (ECORR), and corrosion currents (ICORR) of heat-treated samples, as well as fatigue behavior by creep testing. The von Mises distribution and the resulting microstrains in heat-treated hybrid implants and in cortical and trabecular bone were assessed by finite element analysis. The results of treated hybrid implants were compared to those of untreated hybrid implants and hybrid implants with a rough surface (shot-blasted). Results: The proposed heat treatment (800 °C for 30 min, followed by quenching in water at 20 °C) could successfully homogenize the residual stress difference between the two surfaces of the hybrid implant (−20.2 MPa). It provides better fatigue behavior and corrosion resistance (p ˂ 0.05, ANOVA). Stress distribution was significantly improved in the trabecular bone. Heat-treated hybrid implants performed worse than implants with a rough surface. Clinical significance: Annealing heat treatment can be used to improve the mechanical properties and corrosion resistance of hybrid surface implants by homogenizing residual stresses.

A comparative evaluation of the displacement and stress distribution of Kilroy spring, ballista spring and temporary anchorage devices during traction of palatally impacted canine using a 3 dimensional finite element analysis

The above study comprises a comparative evaluation of the displacement and stress distribution of Kilroy spring, Ballista spring and Temporary anchorage devices during traction of palatally impacted canine using a 3 dimensional finite element analysis. Palatally impacted canine is a common phenomenon occuring in around 8% of individuals. The Finite Element Analysis/Finite Element method (FEA/FEM) is the most intricate and dependable study that significantly revolutionized the world of dentistry and biomechanical research. Stresses and displacements can be precisely located using this type of numerical analysis. The orthodontist can better comprehend the physiological reactions that take place within the dentoalveolar complex because of the quantitative information it gives them. A Cone Beam Computed Tomography (CBCT)scan of the maxilla was obtained from a patient who reported to the Department of Orthodontics and Dentofacial Orthopaedics after he satisfied the inclusion and exclusion criterion. Finite element 3-D models of Kilroy spring, Ballista spring, Cantilever spring, miniscrew, lingual button, 0.022-inch-slot brackets, 0.019x0.025-inch SS archwire, stainless steel bands with molar tubes were constructed using a three-dimensional computer-aided design program (SolidWorks 2017; Solid Works K.K., Tokyo, Japan). All these components were imported and individually assembled in the ANSYS Software (Version 2021 R2, ANSYS, Canonsburg, Pa) and stress analysis was carried out. On the basis of this study following conclusion were drawn: The maximum amount of impacted canine displacement, with initial simulation, wasobserved with Kilroy spring followed by Ballista spring and miniscrew assisted Cantilever spring and the maximum amount of displacement of adjacent teeth i.e. lateral incisor and 1st premolar is observed with Ballista spring followed by kilroy spring and miniscrew assisted Cantilever spring. Furthurmore stress concentration on the canine is highest in case of ballista spring followed by Kilroy spring and miniscrew assisted Cantilever spring. Over all, miniscrew assisted Cantilever spring can be an efficient treatment option for traction of a palatally impacted canine.

Numerical FE Three-phasic Simulation to Predict the Effect of Air Voids on the Dynamic Modulus of Bituminous Composites

In this study, the mechanical performance of bituminous composites was predicted using an upscaling methodology that integrated both finite element analysis and analytical modeling. The FE approach was employed to incorporate intricate geometries and material characteristics. The dynamic modulus of the matrix and the elastic properties of aggregates served as inputs for the numerical models at various scales. This approach considers the distinctive attributes of the granular framework at each level. Furthermore, the investigation involved the influence of air void proportions on the composite's modulus. The numerical models encompassed the random incorporation of air voids within the matrix at varying levels. Notably, it was observed that at low frequencies air voids reduced the dynamic modulus of asphalt more than at high frequencies due to its effect on viscoelastic nature of the bituminous composite. Moreover, heightened temperatures intensified the impact of air void on the dynamic modulus of the asphalt mixture.

Fatigue Assessment of Copper‐Brazed Stainless‐Steel Joints for Plate Heat Exchangers

ABSTRACTCyclic pressures can cause fatigue failure in the brazed joints and plates of the plate heat exchangers (PHEs). This study examines the fatigue behavior of PHEs made from 316L and 304L steels brazed with copper foils employing strain‐controlled fatigue tests to explore if 304L could replace 316L in the existing production line for cost reduction. Fatigue tests were conducted at four different load levels with a stress ratio of zero and a frequency of 5 Hz. Finite Element Analysis was used to assess strain distribution and estimate PHE lifespan based on generated strain versus number of cycles to failure curves. The microstructural analysis revealed that copper diffuses more easily into 316L than 304L, and using 50 μm thick foil causes more defects compared with 100 μm foil. It was shown that 316L joints have a significantly increased fatigue life compared with 304L. Both 316L and 304L met the 15‐year lifetime requirement set by manufacturers.

Biomechanical impact of progressive meniscal extrusion on the knee joint: a finite element analysis.

While measuring meniscal extrusion quantitatively is an early risk factor for knee osteoarthritis (KOA), the biomechanics involved in this process are not well understood. This study aimed to investigate the effects of varying degrees of medial and lateral meniscal extrusion and their material softening on knee osteoarthritis progression. Finite element analysis (FEA) was utilized to simulate varying degrees of meniscal extrusion (1-5mm) in 72 knee joint models, representing progressive meniscal degeneration and material softening due to injury. Changes in von Mises stress of the cartilage and menisci and the load distribution on the tibial plateau's meniscus and cartilage were studied under balanced standing posture in both healthy and injured knees, and statistical analysis was performed using Spearman correlation. Compared to healthy knees, peak stress in medial compartment tissues increased by over 40% with 4mm of medial meniscus extrusion, and in lateral compartment tissues with 2mm of lateral meniscus extrusion. Meniscus extrusion reduced the contact load between the meniscus and femoral cartilage but increased it between the tibial and femoral cartilages, with a maximum increase up to fivefold. Spearman correlation analysis indicated that meniscal extrusion significantly affected peak stress and contact loads in the respective knee compartment (p < 0.001), with a lesser impact on the opposite compartment. Notably, medial meniscal extrusion also significantly increased peak stress in the lateral tibial cartilage (p < 0.05). The quantitative analysis revealed that meniscal extrusion significantly affected the biomechanics of soft tissues within the same compartment, with limited impact on the opposite side. Specifically, Medial extrusion beyond 4mm significantly affected the biomechanics of the medial compartment, while lateral extrusion over 2mm had a similar impact on the lateral compartment. Meniscal softening, without altering joint contact characteristics, primarily affected the biomechanics of the meniscus itself, with minimal impact on other soft tissues.

Comprehensive Biomechanical Characterization of the Flexible Cat Spine via Finite Element Analysis, Experimental Observations, and Morphological Insights

Comprehensive Biomechanical Characterization of the Flexible Cat Spine via Finite Element Analysis, Experimental Observations, and Morphological Insights

Evaluation of the Biomechanical Effects and Stability of Titanium and Carbon Fiber-Reinforced Polyetheretherketone Mini Plates in Le Fort I Advancement Osteotomy Fixation Using Finite Element Analysis.

This study aimed to investigate the biomechanical properties of 60% carbon fiber-reinforced polyetheretherketone (Cfr-PEEK), which exhibits high mechanical strength and can address the limitations of titanium mini plates used in Le Fort I osteotomy. Models were created using the FEA method based on tomography images of adult individuals. A 5 mm maxillary advancement was applied to the models following Le Fort I osteotomy. Mini plates made of titanium and 60% Cfr-PEEK were used. Support was provided by the nasomaxillary and zygomaticomaxillary buttresses to fix a total of four L-shaped mini plates. Oblique loads of 125 N, directed from palatal to buccal, and a total of 250 N compression loads were applied to the central fossa of the premolar and molar teeth in the maxillary model at a 30° angle relative to the long axis of the teeth. Displacement values at the osteotomy line, Von Mises stresses in the mini plate-screws, and principal stresses in the bone were compared. Examination of stress values in the fixation systems of the models revealed higher stress values in the Cfr-PEEK model compared to the titanium model. However, these stresses did not reach levels that would deform the Cfr-PEEK fixation systems. Stress and displacement values in the bone were lower in the Cfr-PEEK model compared to the titanium model. According to the findings of our study, Cfr-PEEK represents a viable alternative to titanium for mini plate material in Le Fort I osteotomy, offering biomechanical advantages.

Computer-aided diagnosis for China-Japan Friendship Hospital classification of necrotic femurs using statistical shape and appearance model based on CT scans.

The purpose of this study is to quantify the three-dimensional (3D) structural morphology, bone mineral density (BMD) distribution, and mechanical properties of different China-Japan Friendship Hospital (CJFH) classification types and assist clinicians in classifying necrotic femurs accurately. In this study, 41 cases were classified as types L2 and L3 based on CT images. Then, 3D Statistical Shape and Appearance Models (SSM and SAM) were established, and 80 principal component (PC) modes were extracted from the SSM and SAM as the candidate features. The bone strength of each case was also calculated as the candidate feature using finite element analysis (FEA). Support vector machine (SVM) and Extreme Gradient Boosting (XGBoost) were used to establish 10 machine learning models. Feature selection methods were used to screen the candidate features. The performance of each model was evaluated based on sensitivity, specificity, accuracy, and the area under the receiver operating characteristic (ROC) curve. This resulted in a SVM model for CJFH classification with the performance: accuracy of 87.5%, sensitivity of 85.0%, specificity of 76.0%, and AUC of 94.2%. This study provided effective machine learning models for assisting in diagnosing CJFH types, increasing the objectivity of the diagnosis. They may have great potential for application in clinical assessments of CJFH classification.

Analysis of Tire-Road Interaction: A Literature Review

This paper presents a comprehensive literature review of the most popular and recent work on passenger and truck tires. Previous papers discuss a huge amount of work on the modeling of passenger car tires using finite element analysis. In addition, recent works on tire–road interaction and the validation of tires using experimental measurements have been described. Moreover, the history of the tire-road contact algorithms is explained. In addition, friction modeling that is implemented in tire–road interaction applications are discussed. Also, a summary of current state-of-the-art research work definitions and requirements of the tread rubber compound are covered from previous studies using various literature reviews and hyper-viscoelastic material models that are implemented for the tread top and the tread base rubber compound. Furthermore, the effect of tire temperature from previous works is presented here. Finally, this literature review also highlights the shortcomings of recent research work and describes the areas lacking in the literature.

Asymptotic-preserving finite element analysis of Westervelt-type wave equations

Asymptotic-preserving finite element analysis of Westervelt-type wave equations