Finite Element Analysis Model Research Articles

Biomechanical evaluation of different plunger size and plunger position on removing soft contact lenses and rigid gas permeable contact lenses.

To avoid risks of mucosal infection from contact lenses removal, a contact lens plunger is often used. Given various types of contact lens plungers available on the market, no study has yet been done on mechanical effects of the contact lens plunger on contact lens removal. Here, this study used finite element analysis to investigate the effects of plunger size and plunger position on the removal of soft and rigid gas permeable (RGP) contact lenses. First, we established finite element analysis models for the plunger, contact lens, cornea, and aqueous humor. The plunger is made of mostly silicone rubber, and the contact lenses are mainly made of soft and hard material. The part of the plunger used for removal was located either at the central or the edged position, with pulling 1 mm distance. The main parameters observation indicators of in this study were the reaction force at the fixed end of the cornea, aqueous humor, the von Mises stress of the plunger, the contact lenses, and the cornea. Results of this study showed that when a plunger of a larger diameter was used, the reaction force of the plunger was also larger, especially when applied to RGP lenses, which required a slightly larger force (∼0.27 N). Also, when removing a RGP lens from the edge, there was a greater stress at the edge of the contact lens (2.5799 MPa), and this caused a higher stress on both the cornea (0.0165 MPa) and the aqueous humor (0.00114 MPa). When using a plunger with a larger diameter to remove a RGP lens, although a larger force required, the relatively larger contact area likely reduced the stress on the cornea and aqueous humor, thereby reducing the risk of eye injury. In addition, when removing a RGP lens, the results of this study recommended it to be removed from the plunger edge, as that facilitated the removal of contact lens.

Parametric analysis on explosion resistance of composite with finite element and artificial neural network

To analyze the factors influencing the explosion resistance of composite laminates subjected to explosive blasts in air, a finite element analysis (FEA) model was utilized. The out-of-plane displacement of composite laminates under far-field airborne explosions could be accurately simulated based on the model. Additionally, an artificial neural network (ANN) model was established to train the data obtained from the FEA model, which allowed for accurate predictions of maximum deflection and its arrival time of laminates with varying parameters, such as impulse of blast, side length, thickness, and mechanical properties of laminates. The results highlighted that the thickness and side length of the composite laminates were critical factors affecting the deformation of laminates under explosive blasts. This research provided a valuable insight aimed at optimizing the design of composite structures to enhance their explosion resistance.

Effect of Post-Cured through Thickness Reinforcement on Disbonding Behavior in Skin-Stringer Configuration.

An experimental investigation of interlaminar toughness for post-cured through-thickness reinforcement (PTTR) skin-stringer sub-element is presented. The improvement in the crack resistance capability of skin-stringer samples was shown through experimental testing and finite element analysis (FEA) modeling. The performance of PTTR was evaluated on a pristine and initial-disbond of the skin-stringer specimen. A macro-scale pin-spring modeling approach was employed in FEA using a non-linear spring to capture the pin failure under the mixed-mode load. The experimental results showed a 15.5% and 20.9% increase in strength for the pristine-PTTR and initial-disbond PTTR specimens, respectively. The modeling approach accurately represents the overall structural response of PTTR laminate, including stiffness, adhesive strength, crack extension scenarios and progressive pin failure modes. This modeling approach can be beneficial for designing damage-tolerant structures by exploring various PTTR arrangements for achieving improved structural responses.

Study on the Effect of Burial Depth on Selection of Optimal Intensity Measures for Advanced Fragility Analysis of Horseshoe-Shaped Tunnels in Soft Soil

Seismic intensity measures (IMs) can directly affect the seismic risk assessment and the response characteristics of underground structures, especially when considering the key variable of burial depth. This means that the optimal seismic IMs must be selected to match the underground structure under different buried depth conditions. In the field of seismic engineering design, peak ground acceleration (PGA) is widely recognized as the optimal IM, especially in the seismic design code for aboveground structures. However, for the seismic evaluation of underground structures, the applicability and effectiveness still face certain doubts and discussions. In addition, the adverse effects of earthquakes on tunnels in soft soil are particularly prominent. This study aims to determine the optimal IMs applicable to different burial depths for horseshoe-shaped tunnels in soft soil using a nonlinear dynamic time history analysis method, and based on this, establish the seismic fragility curves that can accurately predict the probability of tunnel damage. The nonlinear finite element analysis model for the soil–tunnel interaction system was established. The effects of different burial depths on damage to horseshoe-shaped tunnels in soft soil were systematically studied. By adopting the incremental dynamic analysis (IDA) method and assessing the correlation, efficiency, practicality, and proficiency of the potential IMs, the optimal IMs were determined. The analysis indicates that PGA emerges as the optimal IM for shallow tunnels, whereas peak ground velocity (PGV) stands as the optimal IM for medium-depth tunnels. Furthermore, for deep tunnels, velocity spectral intensity (VSI) emerges as the optimal IM. Finally, the seismic fragility curves for horseshoe-shaped tunnels in soft soil were built. The proposed fragility curves can provide a quantitative tool for evaluating seismic disaster risk, and are of great significance for improving the overall seismic resistance and disaster resilience of society.

Soft pads for robotic limbs: achieving human finger compliance via finite element optimization

Human fingers possess compliant contact interfaces with predetermined compliance properties. Replicating these compliance properties in robotic limbs, particularly anthropomorphic hands, can significantly impact grasp stability and contact area. To address the limitations of homogeneous layers of soft material commonly used in anthropomorphic hands, this paper proposes optimizing differentiated structures to design soft pads, which consist of a continuous external layer (skin) coupled with an internal layer featuring voids. To achieve the desired compliance properties replicating those of human fingers, the paper introduces five distinct patterns for differentiated structures, along with their corresponding finite element analysis (FEA) models. Subsequently, by formulating an appropriate optimization function, the shapes of these patterns have been optimized to match the compliance of the human finger, and it has been demonstrated that one of the proposed and optimized pads closely approximates this target through the proposed methodology. The results affirm that this approach offers an effective solution for designing soft pads whose behavior needs to be aligned with the compliance of a specific target.

Cracking modes and force dynamics in the insertion of neural probes into hydrogel brain phantom

Objective. The insertion of penetrating neural probes into the brain is crucial for advancing neuroscience, yet it involves various inherent risks. Prototype probes are typically inserted into hydrogel-based brain phantoms and the mechanical responses are analyzed in order to inform the insertion mechanics during in vivo implantation. However, the underlying mechanism of the insertion dynamics of neural probes in hydrogel brain phantoms, particularly the phenomenon of cracking, remains insufficiently understood. This knowledge gap leads to misinterpretations and discrepancies when comparing results obtained from phantom studies to those observed under the in vivo conditions. This study aims to elucidate the impact of probe sharpness and dimensions on the cracking mechanisms and insertion dynamics characterized during the insertion of probes in hydrogel phantoms. Approach. The insertion of dummy probes with different shank shapes defined by the tip angle, width, and thickness is systematically studied. The insertion-induced cracks in the transparent hydrogel were accentuated by an immiscible dye, tracked by in situ imaging, and the corresponding insertion force was recorded. Three-dimensional finite element analysis models were developed to obtain the contact stress between the probe tip and the phantom. Main results. The findings reveal a dual pattern: for sharp, slender probes, the insertion forces remain consistently low during the insertion process, owing to continuously propagating straight cracks that align with the insertion direction. In contrast, blunt, thick probes induce large forces that increase rapidly with escalating insertion depth, mainly due to the formation of branched crack with a conical cracking surface, and the subsequent internal compression. This interpretation challenges the traditional understanding that neglects the difference in the cracking modes and regards increased frictional force as the sole factor contributing to higher insertion forces. The critical probe sharpness factors separating straight and branched cracking is identified experimentally, and a preliminary explanation of the transition between the two cracking modes is derived from three-dimensional finite element analysis. Significance. This study presents, for the first time, the mechanism underlying two distinct cracking modes during the insertion of neural probes into hydrogel brain phantoms. The correlations between the cracking modes and the insertion force dynamics, as well as the effects of the probe sharpness were established, offering insights into the design of neural probes via phantom studies and informing future investigations into cracking phenomena in brain tissue during probe implantations.

Floor Vibrations of Steel-Framed Floor Systems Due to Rhythmic Activities—Case Study

Human induced vibrations on steel-framed floor systems can result in a wide variety of serviceability problems, ranging from discomfort of building occupants to damage of building components. Rhythmic activities, like aerobics, have the potential to cause significant floor vibrations owing to synchronized crowd movement. This article presents the results of a case study in which the susceptibility of a steel-framed floor system to structural vibrations was evaluated after an aerobic dance event caused damage to non-structural building components. The study assessed a floor supported by a system of long span trusses, which at one end were themselves supported by a two-story deep long span truss. This study consisted of collecting onsite vibration measurements and evaluating the floor system using a numerical model. The finite element analysis model was calibrated using results from field measured data. The numerical analysis results showed that estimated floor accelerations exceeded standard limits for different types of rhythmic activities, indicating that the floor system was susceptible to uncomfortable vibrations. Possible methods to improve the structural response of the floor and to address human discomfort are discussed.

Probabilistic Finite Element Analysis of Human Rib Biomechanics: A Framework for Improved Generalizability.

In dynamic impact events, thoracic injuries often involve rib fractures, which are closely related to injury severity. Previous studies have investigated the behavior of isolated ribs under impact loading conditions, but often neglected the variability in anatomical shape and tissue material properties. In this study, we used probabilistic finite element analysis and statistical shape modeling to investigate the effect of population-wide variability in rib cortical bone tissue mechanical properties and rib shape on the biomechanical response of the rib to impact loading. Using the probabilistic finite element analysis results, a response surface model was generated to rapidly investigate the biomechanical response of an isolated rib under dynamic anterior-posterior load given the variability in rib morphometry and tissue material properties. The response surface was used to generate pre-fracture force-displacement computational corridors for the overall population and a population sub-group of older mid-sized males. When compared to the experimental data, the computational mean response had a RMSE of 4.28N (peak force 94N) and 6.11N (peak force 116N) for the overall population and sub-group respectively, whereas the normalized area metric when comparing the experimental and computational corridors ranged from 3.32% to 22.65% for the population and 10.90% to 32.81% for the sub-group. Furthermore, probabilistic sensitivities were computed in which the contribution of uncertainty and variability of the parameters of interest was quantified. The study found that rib cortical bone elastic modulus, rib morphometry and cortical thickness are the random variables that produce the largest variability in the predicted force-displacement response. The proposed framework offers a novel approach for accounting biological variability in a representative population and has the potential to improve the generalizability of findings in biomechanical studies.

Applications of Finite Element Analysis in Endodontics: A Systematic Review and Meta-Analysis

ABSTRACT Background: Endodontics increasingly uses finite element analysis (FEA) to evaluate stress distribution, fracture resistance, and temperature changes in treated teeth. FEA’s endodontic uses, benefits, and drawbacks are examined in this systematic review and meta-analysis. Methods: A PubMed systematic search found relevant studies published up to January 2022. Original endodontic research articles utilizing FEA to quantify stress distribution, fracture resistance, or temperature changes in treated teeth were eligible. The systematic review comprised 30 publications, 15 of which were meta-analyzed. Data were extracted using a standard form, and the “Newcastle-Ottawa Scale (NOS)” for observational studies and the Cochrane risk of bias tool for randomized controlled trials assessed quality. Random-effects models calculated pooled effect sizes and 95% confidence intervals in RevMan 5.4 meta-analysis. Results: Meta-analysis shows FEA-guided endodontic treatment improves stress distribution (P < 0.001) and fracture resistance (P < 0.05) compared to conventional treatments. The temperature did not vary significantly (P = 0.12). Stress distribution had an effect size of 0.75 (95% CI: 0.65–0.85), fracture resistance 0.42 (95%: 0.12–0.72), and temperature variations -0.18. Conclusion: In conclusion, FEA is a valuable technique in endodontics for stress distribution study and fracture resistance testing. FEA models’ accuracy, dependability, and clinical applicability were questioned, underlining the need for more research and development to maximize their endodontics clinical use.

In situ interfacial evaluation of aramid/epoxy composites by interfacial stress transfer characteristics.

Interfacial bonding between aramid fibers and epoxy resin is crucial for the mechanical properties of fiber-reinforced epoxy composites. Interfacial stress transfer between resin and fibers bridges microscopic and macroscopic properties. Using micro-Raman spectroscopy for in situ stress measurement offers insights into interface bonding through assessment of interfacial stress transfer characteristics. This study measures stress distribution on loaded microdroplet sample surfaces, analyzes stress transfer at the interface, and proposes an evaluation method using finite element analysis (FEA). The results show that interfacial stress along the fiber decreases from the droplet's edge to center, indicating stress transfer between the fiber and matrix, as evidenced by the stress-dependent Raman shift of aramid fiber. The interface modulus (Eif), derived from the FEA model, effectively reflects interface bonding, with droplet shape influence removed in evaluations. The agreement between the proposed method and the transverse fiber bundle test confirms its applicability. The method offers a direct, non-destructive, and shape-independent way to evaluate the interface of aramid/epoxy composites.

Biomechanical Effect of Ankle Ligament Injury in AO Type 44B2.1 Lateral Malleolus Fractures After Lateral Plate Fixation: A Finite Element Analysis.

Distal fibula fractures at the ankle level are common and are usually accompanied by ligament injuries. This study aims to evaluate the effects of ankle ligament ruptures on ankle joints, fracture instability, and plate stress after distal fibula fracture fixed with a plate created by finite element analysis modeling and loading applied to ligament rupture models that may accompany this fracture. A finite element model consisting of three-dimensional fibula, tibia, foot bones, and ankle ligaments was designed to investigate the effects of ligament injuries accompanying plate-detected AO type 44B2.1 fractures on fracture detection, fixation material, and ankle joints. Then, the results were evaluated by modeling ligament rupture in six different ways. In the modeling where the deltoid and talofibular ligaments are broken together, instability is highest in the ankle (2.31 mm) and fracture line (0.15 mm). The rupture of the anterior and posterior tibiofibular ligaments associated with syndesmosis caused less instability in the fracture and ankle than the single-ligament rupture models of both the deltoid and talofibular ligaments. In the finite element modeling of AO type 44B2.1 fractures detected with plate, the importance and potential effects of often-overlooked ankle ligament injuries are pointed out. Note that when treating ankle injuries, the ankle should be treated as a whole, with both bone and soft tissue. In some cases, the fracture may represent the visible tip of the iceberg.

Analysis of structural dynamic response of vertical sound barriers under natural wind and vehicle induced pulsating wind effects

Abstract Aiming at the influence of natural wind and vehicle-induced pulsating wind on vertical sound barriers, a finite element plug-in panel sound barrier is established based on the finite element method for dynamic response analysis. This paper establishes a sound barrier finite element analysis model based on finite element analysis software. It takes the 8-span vertical sound barrier as the basic working condition to analyze the dynamic response analysis of the sound barrier structure under the action of natural wind of different grades, i.e., the influence of pressure and displacement; the dynamic response of the sound barrier structure with a natural wind speed of 7 grades or more. In addition, it analyzes the dynamic properties of the sound barrier structure caused by train-induced pulsating wind pressure at speeds of more than 200 km/h, i.e., the influence of pressure and displacement, and investigates the dynamic characteristics of different vehicles with different wind speeds, pressure, and displacement. Furthermore, the response of the vertical sound barrier at different vehicle speeds is also explored, and the results are compared to examine its dynamic response. The research findings show that the sound barrier structure does not resonate during the self-resonance analysis, but the vibration of adjacent sound barrier panels affects each other. As natural wind speeds increase, the displacement of the steel column endpoints of the vertical sound barrier gradually increases; along the length of the sound barrier, the change of the peak pressure at the top of the steel columns and the top of the unit plate shows a symmetrical trend, and the displacements of the steel columns and the top of the unit plate show a trend of gradual increase in the travelling direction, and they both increase at the end of the column. The displacement of the top of the steel column and the top of the unit plate both show a trend of gradual increase along the direction of the vehicle, and both reach the maximum value at the end of the steel column and the unit plate. With the increase in vehicle speed, the overall peak displacement value also increases synchronously.

Evaluation method of residual life of casing with corrosion defect in CO2 injection Wells

With the hot development of CCUS project in major oil fields, CO2 flooding technology is also developing continuously. CO2 flooding needs to transform old oil field Wells into CO2 Wells, and the residual life of casing with corrosion defects in old oil Wells needs to be evaluated. To solve this problem, the residual strength of casing with corrosion defects under the combined force is analyzed, and a finite element analysis model is established considering the material nonlinearity. It is found that the temperature difference and axial force will significantly reduce the residual strength of casing. The influence of corrosion rate and pitting pit radius on the residual life of CO2 injection well is discussed. It is found that well H can continue to serve for 13 years after CO2 injection. The research results can provide a theoretical basis for predicting the residual life of CO2 injection Wells in old wells, and ensure the normal production and operation of CO2 injection flooding development.

Finite element analysis and simplified envelope curve model for RC shear key under earthquake-tsunami actions

Coastal bridges are vulnerable to the compounded effects of earthquakes and subsequent tsunamis. Their limited lateral restraints can result in critical risks such as the deck unseating or overturning. To this end, reinforced concrete (RC) shear keys are often integrated to enhance the superstructure resilience. While previous studies have investigated their seismic performance, their effects under seismic-tsunami actions remains relatively unexplored yet. This study employed finite element (FE) analysis to examine shear key properties under such conditions, with emphasis on hysteretic curves, concrete damage, and strain evolution. The FE model was developed in accordance with precedent tests, and the modeling results were also compared with tests. A simplified envelope curve model was developed using both geometry and rebar configuration, with various damage states included to reckon their seismic damages after initial earthquakes. The proposed model was validated and aligned well with test results. Further, a framework was proposed to determine the envelope curve for bridges at different damage stages. This study aims to provide insights into the seismic-tsunami analysis on coastal bridges by considering their varying properties under seismic and tsunami actions.

Evaluating the Mechanical Strength of Three Dimensionally (3D) Printed Implants in Septorhinoplasty through Finite Element Analysis (FEA).

Autologous nasoseptal cartilage grafts are used to correct nasal asymmetry and deviation in rhinoplasty, but patients who have undergone multiple surgeries may have limited autologous cartilage tissue available. 3D-printed L-strut implants may address these challenges in the future, but their mechanical strength is understudied. Silk fibroin-gelatin (SFG), polycaprolactone (PCL), and polylactide (PLA) are bio-inks known for their strength. We present Finite Element Analysis (FEA) models comparing the mechanical strength of 3D-printed SFG, PCL, and PLA implants with nasoseptal cartilage grafts when autologous or allografts are not available. FEA models compared the stress and deformation responses of 3D-printed solid and scaffold implant replacements to cartilage. To simulate a daily force from overlying soft tissue, a unidirectional load was applied at the "keystone" region given its structural role and compared with native cartilaginous properties. 3D-printed solid SFG, PCL, and PLA and scaffold PCL and PLA models demonstrated lower deformations compared to cartilage. Solid SFG balanced strength and flexibility. The maximum stress was below all materials' yield stresses suggesting their deformations are unlikely permanent under a daily load. Our FEA models suggest that 3D-printed L-strut implants carry promising mechanical strength. Solid SFG's results mimicked cartilage's mechanical behavior. Thus, scaffold SFG merits further geometric optimization for potential use for cartilage substitution. 3D-printed septal cartilage replacement implants can potentially enhance surgical management of patients who lack available donor cartilage in select settings. Computational simulations can evaluate 3D-printed implant strength and their potential to replace septal cartilage in septorhinoplasty.

Performance-based design of environmental parameters for offshore wind turbine foundations

Taking into account the coupling effects of wind, wave, and current on offshore wind turbines (OWTs), a combined approach utilizing non-linear finite element analysis (FEA), back propagation neural network (BPNN), and probabilistic statistical methodology (PSM) is proposed for accurate environmental parameter estimation in OWT foundation design. The structural bearing performances of OWT foundations are precisely predicted through a combination of FEA and BPNN models, and then serve as constraints for probabilistic statistical analysis. Furthermore, for PSM, a robust multivariate joint probability distribution is constructed leveraging copula functions, which not only maximizes marginal information but also effectively captures the intricate dependencies among ocean environmental parameters. Subsequently, the proposed models, along with traditional univariate analysis, are utilized to estimate the return values of diverse load combinations. The results indicate that, for a given return period, the conditional probability model yields lower wave heights and current velocities compared to univariate analysis, while the joint probability model results in lower values for all ocean parameters, making both approaches more suitable for OWT foundation design. This coupled approach presents a more rational and cost-effective solution compared to univariate analysis, potentially resulting in decreased investment costs.

Numerical investigation of plastic hinge length and lateral displacement capacity in precast concrete columns reinforced with SFCBs

Basalt fiber-reinforced polymer (BFRP) presents several advantages, including a moderate elastic modulus, cost-effectiveness, and a substantial fracture strain. A steel-FRP composite bar (SFCB) is a composite bar consisting of an inner steel bar and outer longitudinal BFRP, and it offers favorable initial modulus, high durability, and controllable post-yield stiffness. This study aims to address the issue associated with poor corrosion resistance, connection defects, and low integrity in traditional precast concrete columns with grouted sleeves (PCC-GSs) by employing bond- and post-yield-controlled precast concrete columns reinforced with SFCBs (PCC-SFs). The 3D finite element analysis (FEA) modeling was validated by comparing the results with those of six PCC-SFs and three precast reinforced concrete (RC) columns obtained from the experiment. The results encompass failure modes, load-displacement responses, strain distributions of SFCBs, and section curvature along the columns. The predicted errors for the peak load of S10B85–1P, S10B85–2P, and S10B85–3P are 6.4%, 0.1%, and 1.9%, with a mean error of 2.8%. The predicted errors for the ultimate deformation of S10B85-3PL and ST10B85–3P are within 20%, with a value of 6.0% and 18.7%. Subsequently, a series of FEA models were developed to analyze the effects of various on the development mechanism of plastic hinge length (PHL) for the PCC-SFs under lateral loading. The parameters included the post-yield stiffness ratio, equal-stiffness reinforcement ratio, axial force ratio, concrete strength, and bond strength. The longest plastic hinge length can reach 1.91D (D is the width of the column). An adjusted prediction model for the equivalent PHL in PCC-SFs was proposed and evaluated following a discussion of existing empirical models. Finally, the study explored the effects of these parameters on the load-displacement response, and the rationality of Priestley's shear-strength degradation model in PCC-SFs was validated. Based on the CEN model, an improved prediction model of the total chord rotation capacity was proposed.

Determinants of Maximum Magnetic Anomaly Detection Distance.

The maximum detection distance is usually the primary concern of magnetic anomaly detection (MAD). Intuition tells us that larger object size, stronger magnetization and finer measurement resolution guarantee a further detectable distance. However, the quantitative relationship between detection distance and the above determinants is seldom studied. In this work, unmanned aerial vehicle-based MAD field experiments are conducted on cargo vessels and NdFeB magnets as typical magnetic objects to give a set of visualized magnetic field flux density images. Isometric finite element models are established, calibrated and analyzed according to the experiment configuration. A maximum detectable distance map as a function of target size and measurement resolution is then obtained from parametric sweeping on an experimentally calibrated finite element analysis model. We find that the logarithm of detectable distance is positively proportional to the logarithm of object size while negatively proportional to the logarithm of resolution, within the ranges of 1 m~500 m and 1 pT~1 μT, respectively. A three-parameter empirical formula (namely distance-size-resolution logarithmic relationship) is firstly developed to determine the most economic sensor configuration for a given detection task, to estimate the maximum detection distance for a given magnetic sensor and object, or to evaluate minimum detectable object size at a given magnetic anomaly detection scenario.

Constructing a Microdiffusion-Seepage-Stress Multifield Coupling Model for Nanopore Gas.

Existing research is difficult to fully capture the correlation between gas molecules and pore wall interactions, multiphase flow, and stress distribution in nanopores. Taking gas as an example, a microscopic model was constructed. At the same time, diffusion, seepage, and stress were considered to accurately predict and manage gas transport in nanopores. First, molecular dynamics (MD) simulation methods were adopted to simulate the motion trajectories and interactions of gas molecules in nanopores. Second, a multiscale model was established based on continuum mechanics to consider the interaction between pore walls and gas molecules, and a diffusion equation was established to describe the diffusion process of gas molecules in pores. Then, finite element analysis and porous media models were used to simulate the seepage behavior of gas in the nanopores. Finally, the stress distribution in the pores was analyzed, and the influence of the interaction between the pore wall and gas molecules on stress was considered. The multifield coupling model was experimentally evaluated from three aspects: diffusion coefficient, seepage behavior, and stress distribution. The root-mean-square error (RMSE) and mean absolute error (MAE) of the model in different testing directions were calculated using different simulation tools, such as COMSOL, ANSYS, OpenFOAM, and CFX. The mean values of RMSE and MAE were lower than 0.20 and 0.17, respectively. The constructed model can comprehensively describe gas transmission within nanopores, improving the management accuracy and efficiency.

Biomechanical Analysis of Orthodontic Miniscrew-Assisted Rapid Palatal Expansion on Dental and Bone Tissues: A Finite-Element Study

Abstract This study aims to delineate the biomechanical responses in both soft and hard tissues, alongside the interactions within the surrounding bone of a human skull subjected to clinical loadings generated by a miniscrew-assisted rapid palatal expansion (MARPE) device. Cone-beam computed tomography (CBCT) scans of a 20-year-old female skull were segmented. The skull bones were meticulously modeled to reconstruct a comprehensive three-dimensional (3D) model for finite-element analysis (FEA). A displacement of 0.125 mm was applied on each side (0.25 mm total) of the MARPE device to simulate one complete turn of the jackscrew. The outcomes revealed that the miniscrews experienced a maximum equivalent von Mises stress of 264.91 MPa. Notably, the separation of the midpalatal suture exhibited a quasi-parallel deformation with an average displacement of 0.247 mm and a standard deviation of 0.006,67 mm. The ratio of the rotational angle to the lateral displacement of the zygomaticomaxillary complex was 0.6436 degree/mm. No fracture of miniscrews was observed during the activation of one turn per day.