Load Distribution Research Articles

Beyond support: exploring the dynamic and static biomechanical changes induced by preventive ankle taping: a novel cross-sectional study

Introduction In sports, 80% of all ankle injuries are sprains of the external compartment. Functional bandages are usually used preventively, specially in individuals with a history of lateral ankle injuries. To this day, the actual benefits of such taping remain unknown as important modifications are introduced in the ankle biomechanics. Objective The aim of the present study is to describe the biomechanical processes underlying these effects, such as modification during stance times, balance, contact surface and maximum and average pressures in the rearfoot, forefoot and midfoot, using a sprain preventive taping for the external ankle compartment. Methods An observational, analytic, cross-sectional study was designed. Data from static and dynamic plantar pressures with a pressure platform and balance data assessed with the Y Balance Test (YBT) were analysed in 50 participants (age = 21.00 ± 2.34 years, weight = 71.11 ± 13.12 kg, height = 1.75 ± 00.9 m, BMI = 22.94 ± 2.50 kg/m2, foot size = 41.60 ± 3.00) with and without preventive functional taping for lateral ankle sprain (LAS). Results A statistically significant decrease in YBT was observed in the taped participants toward anterior (p = 0.001) and posterolateral (p = 0.005) motion. On the static measures at the pressure platform, an increase in peak pressure at the midfoot (p = 0.001), a decrease in the maximum pressure in the forefoot (p = 0.003) and a decrease in the contact surface in the rearfoot (p = 0.003) were recorded. Dynamic measures at the pressure platform analysis showed a statistically significant decrease in contact surface at the rearfoot (p = 0.001), an increase in mean pressure in both the midfoot (p = 0.044) and forefoot (p = 0.001) and a significant decrease in velocity in the forefoot (p = 0.003). Conclusions In conclusion, we observed that ankle taping led to increased peak pressures in the midfoot and decreased maximum pressures in the forefoot, indicating a shift in load distribution within the plantar surface. Simultaneously, a significant reduction in the velocity at the forefoot during dynamic tasks suggests that taping may alter natural gait dynamics, potentially affecting movement efficiency and stride characteristics. In addition, the application of ankle taping significantly altered balance, as evidenced by a decrease of YBT scores anterior and posterolateral directions. Prophylactic taping in patients with no prior history of LAS is not recommended.

Improved primary stability and load transfer of a customized osseointegrated transfemoral prosthesis compared to a commercial one

BackgroundTransfemoral osseointegrated prostheses, like other uncemented prostheses experience the risk of aseptic loosening and post-operative periprosthetic fractures, with an incidence between 3% and 30%. To date, however, osseointegrated off-the-shelf prostheses are manufactured in a limited number of sizes, and some patients do not meet the strict eligibility criteria of commercial devices. A customized osseointegrated stem was developed and a pre-clinical in vitro investigation of the stem was performed, to evaluate its biomechanical performance.Materials and methodsSix human cadaveric femurs were implanted with commercial stems, while the six contralateral were implanted with customized stems. Three more femurs that did not meet the eligibility criteria for the commercial stems were implanted with the customized stems. Two different loading scenarios (compression-flexion, and torsion) were simulated to measure the primary implant stability and the load transfer. For both loading scenarios, the displacements of the implant with respect to the host bone, and the strains on the bone surface were measured using digital image correlation (DIC). To measure the pull-out force, a tensile force was applied to the prostheses.ResultsThe translational inducible micromotions during the compression-flexion test of the OsteoCustom stem were more than 4 times smaller than the commercial one (p < 0.05). The rotational inducible micromotions of the OsteoCustom stem were more than 3 times smaller than the commercial one (p < 0.05). Similar results were found from the torsional test. The full-field strain distribution of the commercial stem showed a slightly higher strain concentration near the stem tip (maximum principal strain = 1928±127 µɛ) than the OsteoCustom (maximum principal strain = 1758±130 µɛ). Similar results were found for the femurs that did not meet the eligibility criteria for the commercial stems and could be implanted with the OsteoCustom. No statistically significant difference was found in the extraction force between the two groups.Discussion and conclusionThese results support the hypothesis that the OsteoCustom stem can offer better primary stability and load distribution compared to commercial implants. The outcome highlighted the potential benefits of the OsteoCustom prosthesis, which is capable of including a wider range of femoral anatomies than the current standard.

Multi-Cloud Deployment with Kubernetes: Challenges, Strategies, and Performance Optimization

In this paper, the challenges, strategies, and techniques involved in the right use of Kubernetes to perform multi-cloud are summarised. Some of them are lack of coordination between different systems and domains, security concerns and costs and providing solutions in terms of how coordination might be most appropriate and how different kinds of automation might be most usefully employed. The following performance optimization techniques are also considered: as the concepts of resource management and load distribution. Keywords: Multiple Cloud Operating Model, Kubernetes Virtualization, Resource Optimization,

Design methodology for heavy-haul railway track foundations under 40-tonne axle loads

ABSTRACT Heavy haul railway, recognized for high capacity and efficiency, is gaining traction worldwide. However, heavier axle loads can accelerate track and foundation deterioration without robust structural design. This study proposes a practical design methodology for heavy-haul track foundations under 40-tonne axle loads. Short axle spacing was considered in analyzing train load distribution, revealing significant stress superposition on the subgrade. Based on general strength, deformation, and long-term stability, a standardized multi-axle load pattern (4Z1800/2400) is introduced to capture these effects. The recommended design ensures cumulative deformation remains within the subgrade “working zone” by integrating induced stress levels and fill materials, surpassing single-factor approaches. Long-term stability, indicated by cumulative deformation approaching slow convergence, serves as the control requirement. Proposed design solutions include: 1) roadbed thickness of 3.5 m, with subgrade reaction modulus (K30) ≥110 MPa/m below the roadbed; 2) lower roadbed of 2.3 m, K30 ≥130 MPa/m, with thickness adjustments as needed; 3) upper roadbed of 0.7 m using high-quality graded gravel. These measures effectively control deformation, thus ensuring the performance and longevity of heavy-haul track foundations under extreme axle loads. The outcomes support global heavy-haul development.

Tooth design and verification of face spline transmission in hub bearing

The hub bearing with face spline transmission is a new type of hub bearing. The design method and standards are lack. In this work, the geometric relationship of the tooth profile parameters and the meshing situation are derived for the hub bearing face spline. The outer diameter D, number of teeth Z, and face tooth profile angle φ are key design parameters. The verification conditions for preload, extrusion stress, tooth root bending stress, and shear stress are established based on strength theory and assumption of uniform load distribution. To validate the design, a case study is conducted on the hub bearing face spline in a certain vehicle model, with theoretical calculation and simulation of stress by using Finite Element Method. The present FEM results compare well with those of the literature data. Finally, through the incorporation the torque strength and durability tests of the face spline, the reliability of the design theory in this work is confirmed. The results indicates that, the tooth tip fillet r1 has a significant impact on the meshing area, the maximum principal stress near the tooth root is highest at the arc of the tooth root, proving that the selection of the dangerous section is appropriate. The work has value in promoting the development of automotive wheel hub bearings.

Controlling Engine Load Distribution in LNG Ship Propulsion Systems to Optimize Gas Emissions and Fuel Consumption

The increasing emphasis on environmental sustainability and stricter gas emissions regulations has made the optimization of fuel and emissions a crucial factor for marine propulsion systems. This paper investigates the potential to improve fuel efficiency and reduce emissions of LNG ship propulsion systems by using different load sharing strategies in Dual-Fuel Diesel-Electric (DFDE) propulsion systems. Using data collected from on-board cyclic measurements and an optimization model, the effects of different load sharing strategies for various types of fuel, such as HFO, MDO, and LNG, under different engine load conditions were investigated. The results of these strategies are compared with those of on-board power management systems (PMS), which evenly allocate power among the engines, irrespective of fuel usage and emission levels. The results show that load adjustments according to the optimization model can considerably increase fuel economy and contribute to the reduction of CO2 and NOx compared to standard practice at the equal load in different ship operating modes. Our approach introduces an innovative optimization concept that has been proven to improve fuel efficiency and reduce emissions beyond standard practices. This paper demonstrates the robustness of the model in balancing environmental and operational objectives and presents an effective approach for more sustainable and efficient ship operations. The results are in line with global sustainability efforts and provide valuable insights for future innovations in energy optimization and ship emission control.

A biomechanics-oriented study on the impact of AIGC on user interaction and ergonomics in visual communication design

This study investigates the biomechanical implications and ergonomic impacts of AI-generated content (AIGC) integration in visual communication design workflows. Through a comprehensive analysis of 23 professional designers in Chengdu, China, we examined the physical stress patterns, user interaction dynamics, and overall ergonomic outcomes when transitioning from traditional to AIGC-assisted design processes. The research employed a mixed-method approach combining quantitative biomechanical measurements with qualitative user experience assessments over 12 weeks. Results revealed significant reductions in muscle activity across key muscle groups, with the upper trapezius showing the most significant decrease (−3.6% MVC, p &lt; 0.001) during AIGC-assisted tasks. This change in muscle activity can be further linked to alterations in the body's postural stability and load distribution, which are core considerations in biomechanics. Movement efficiency metrics, which are inherently related to biomechanical performance, demonstrated a 27.9% reduction in task completion time (p &lt; 0.001) and a 33.3% decrease in design iterations. Quality assessment scores improved across all dimensions, with Creative Innovation showing the highest enhancement (+1.8 points, p &lt; 0.001). User satisfaction metrics indicated significant improvements, with consistent gains of 1.1 points (on a 5-point scale) across all measured dimensions (p &lt; 0.001). Notably, the study identified distinct adaptation patterns between novice and experienced users in terms of their biomechanical responses. Experienced users demonstrated significantly faster response times in AIGC prompt input (8.94 ± 1.87 s vs 18.62 ± 3.15 s, p &lt; 0.001), which can be associated with differences in their neuromuscular coordination and motor learning abilities. While AIGC integration initially increased certain types of errors (+51.2% in input errors), it led to substantial reductions in tool misuse (−40.4%) and design revisions (−39.9%). These findings suggest that AIGC integration can significantly reduce physical stress while improving design efficiency and quality outcomes, all of which are intertwined with the biomechanical functioning of the body during the design process. The research provides evidence-based recommendations for optimizing AIGC implementation in professional design workflows, taking into account the biomechanical and ergonomic factors that contribute to the overall well-being and creative productivity. This study has important implications for software development, workplace health policies, and the future direction of AI-assisted creative work, as it highlights the significance of considering biomechanics in the integration of advanced technologies within creative domains.

A coupled dynamics model for studying the outer ring fault characteristics and mechanisms of axle-box bearings in urban rail vehicles

With the rapid and large-scale development of urban rail transit in China, the operational safety of urban rail vehicles is highly concerned. The axle-box bearing, as the core component of vehicle bogies, directly determines the operational safety and quality of vehicles. To ensure the service performance of axle-box bearings, their fault characteristics should be monitored and diagnosed in time. A more realistic and in-depth understanding of fault characteristics is a prerequisite for fault diagnosis. Thus, a double-rows tapered roller bearing (DTRB)-vehicle-track coupled dynamic model was built via the co-simulation in this paper, which comprehensively considers a DTRB model with the localised outer ring raceway fault, as well as the flexibilities of the wheelset, axle-box, and bogie frame. Its correctness and rationality were verified by the theoretical comparison and the field test. The results indicate that the distribution of contact load is consistent with the theoretical value, the fault features of the outer ring raceway can be found in the periodic impulse of the roller-raceway contact load. The slip rates of rolling elements are less than 4.3 %. Compared with the field test, the fault order harmonics in the order spectrum of the simulation are closer to the theoretical fault characteristic order under variable and constant speed conditions, and the maximum error is only 0.37 %. Therefore, the proposed coupled dynamic is correct and can be employed to investigate the fault characteristics of axle-box bearings in urban rail vehicles.

Finite Element Analysis of Functionally Loaded Subperiosteal Implants Evaluated on a Realistic Model Reproducing Severe Atrophic Jaws.

Implant-supported prosthetic rehabilitation for patients with severely atrophic jaws is challenging due to complex anatomical considerations and the limitations of conventional augmentation techniques. This study explores the potential of subperiosteal (juxta-osseous) implants as an alternative solution, using finite element analysis (FEA) to evaluate mechanical performance. Realistic jaw models, developed from radiographic data, are utilized to simulate various implant configurations and load scenarios. Results indicate that different screw placements, implant designs, and structural modifications can significantly influence stress distribution and biomechanical behavior. Upper and lower jaw models were assessed under multiple load conditions to determine optimal configurations. Findings suggest that strategic adjustments, such as adding posterior screws or altering implant connections, can enhance load distribution and reduce stress concentration, particularly in critical areas. Tensile loads in critical bone areas near cortical fixing screws exceeded 50 MPa under anterior loading, while configurations with larger load distributions reduced stress on both implant and bone. The study provides evidence-based insights into optimizing subperiosteal implant design to improve stability, longevity, and patient outcomes.

Correlation between Properties of Axle Load Distribution and Rigid Pavement Performance Measures

Correlation between Properties of Axle Load Distribution and Rigid Pavement Performance Measures

On the Boundary Conditions in Out-of-Plane Analysis of Thin Plates by the Finite Point Method

The finite point method (FPM) is a numerical, mesh-free technique for solving differential equations, particularly in fluid dynamics. While the FPM has been previously applied in solid mechanics to analyze plates under in-plane loading, there remains a notable scarcity of research exploring the out-of-plane analysis of elastic plates using this method. This study thoroughly investigates the elastic FPM analysis of thin plates subjected to transverse loadings, focusing specifically on various boundary conditions (BCs). Boundary conditions represent a significant challenge in the out-of-plane analysis of thin plates within the FPM framework. To address this challenge, the approach incorporates additional nodal points positioned close to each boundary node, supplementing the points distributed throughout the plate’s interior and along its edges. The strong form of the governing equation is employed for the interior points, while the analysis also includes the scenario of a plate resting on boundary columns. Both distributed and concentrated external loads are examined to provide a comprehensive understanding of the behavior under different loading conditions. Furthermore, the optimal placement of the extra boundary nodes is briefly discussed, alongside a focus on the number of nodes within the finite point clouds. An appropriate range for this number is proposed, although the determination of the optimal distance for the extra boundary nodes and the ideal number of cloud points is earmarked for future research. The contribution of this work is to enhance the understanding of the FPM in the context of thin plates, particularly concerning the critical influence of boundary conditions.

Non-Stationary Wind Loading Identification for Large Transmission Tower Based on Dynamic Finite-Element Model Updating

An effective approach to deal with the structural failures of transmission towers in tornadic events is to develop good structural health monitoring (SHM) systems for them. However, the strategy for SHM of transmission towers against tornados should be different from the conventional atmospheric boundary layer (ABL) winds oriented ones, as the non-stationary nature of the tornados significantly differentiates them from the ABL winds. To satisfy the need of obtaining the highly time-varying whole-field stress on the structure in the course of the tornadic event for effective SHM, an innovative transient tornadic load distribution identification method is proposed for use, which is based on the field structural mode shape measurement and dynamic finite-element (FE) model updating. Via a numerical case study, it is noted that good effectiveness is achieved for the new load distribution identification method. Employing the Modal Assurance Criteria based FE model updating technique, the new method has the advantage of being easily embraced in practical SHM systems. It is found that when the transient tornadic velocity profile to be identified is noticeably different from the mode shape of the structure without undertaking external loads, the identified load pattern is very accurate for the new approach.

Numerical modeling of clamp load relaxation of plastic nuts under varying moisture and fiber contents

Abstract This study presents a numerical approach using a 3D finite element model to quantify the remaining clamp load of a plastic nut joint after a specific time. The viscoelastic relaxation of a thermoplastic nut, which is predominantly screwed on a welding stud, is described by a material card using Prony Series. Prony Series are derived from experimental dynamical mechanical analysis with different moisture and fiber contents of the thermoplastic. Since plastic nuts usually do not have preformed threads, the increased temperatures and resulting stresses from the thread-forming process are considered in the simulation. An FE model is created and verified by substrate stress relaxation tests. Experimental clamp load measurements with miniature compression load cells verify the clamp load prediction and show a good agreement. The developed model is used to analyze the clamp load distribution within the threads and reveals an almost even distribution within the threads.

The role of SOL plasma in the confinement of NBI fast ions in W7-X

Abstract The impact of the SOL (Scrape-Off Layer) plasma on deposition, confinement and losses of NBI fast ions was investigated in W7-X plasma. The effect of SOL width, density, temperature profiles, radial electric field, and charge-exchange reactions (CX) was explored. Ionization and slowing down partly counterbalance each other, as slowing down in cold SOL plasma compensates for ionization effects in radially decaying model profiles. However, the effect of SOL plasma on more vulnerable steel components is mitigating over wide range&amp;#xD;of different profiles as for those components the collisionality effect overrules the effect of SOL on ionization. Also, the effect of radial electric field is mitigating for steel components for experimentally observed direction of the field. Effect of CX reactions is shown to lead to widely spread low power load distribution with no clear effect on peak load. Statistical challenges caused by hugely varying triangle sizes in discretization of wall are discussed.

Intelligent Saturation Power Limit Load Distribution Algorithm (ISPLLDA) for Cooperative Manipulators Applications

Cooperative manipulators face challenges related to an inadequate distribution of external loads and a decrease in Dynamic Load Carrying Capacity (DLCC). Understanding the impact of optimal load distribution on power consumption, load carrying capacity, and gripper error is crucial. This paper presents the Intelligent Saturation Power Limit Load Distribution Algorithm (ISPLLDA), a novel method that achieves optimal external load distribution. ISPLLDA dynamically distributes the external load among manipulators based on torque-bearing capacity and actuator position. Additionally, nonlinearity in system dynamics introduces uncertainties, leading to incorrect DLCC evaluation, increased error, and higher actuator power consumption. To address this, a Radial Basis Function Neural Network (RBFNN) accurately determines actuator saturation limits in the presence of uncertainty, enabling correct estimation of system dynamics and external disturbances. ISPLLDA ensures near-simultaneous saturation of all manipulators' actuators, maximizing their capacity utilization. The proposed method is validated through simulations and experimental tests on cooperative manipulators. Results demonstrate a 17% increase in load-carrying capacity, as well as more than 35% improvement in error and torque indexes compared to the Lagrange multipliers method.

A Comparative Finite Element Analysis of Titanium, Autogenous Bone, and Polyetheretherketone (PEEK)-Based Solutions for Mandibular Reconstruction.

A digital model of the mandible was created from CBCT data and optimized for FEA. Three reconstruction scenarios were simulated: fixation with a titanium plate, reconstruction with an autogenous fibular graft stabilized with the same titanium plate, and fixation with a customized PEEK plate. Various plate thicknesses were analyzed to determine the stress and deformation patterns under masticatory loads. Titanium plates provided superior mechanical stability but showed stress concentrations near screw fixation points. The addition of autogenous bone grafts reduced stress on the plate and improved structural integrity. PEEK plates exhibited reduced stress shielding and better load distribution, but thinner designs were prone to deformation. Minimum recommended thicknesses of 1.2 mm for titanium plates and 1.8 mm for PEEK plates were identified by FEA. This study highlights the importance of material selection and patient-specific design in mandibular reconstruction. Autogenous bone grafts combined with titanium plates demonstrated the best biomechanical outcomes, while PEEK plates offer a promising alternative, particularly for patients where grafting is contraindicated.

Load Sensitivity Correlation Factor-Based Steady-State Power Flow Allocation Method for Independent DC Bus Structure Multiport Power Electronic Transformer

The independent DC bus structure multiport power electronic transformer (IDBS-MPET) is a novel power electronic transformer designed to integrate multiple DC sources and DC loads. Due to the configuration of DC ports, which are directly constructed by the parallel connection of dual active bridge (DAB) converters, the distribution of DC sources and DC loads among the three phases becomes unbalanced. In cases where the load power at certain ports is too high, this imbalance may lead to the over-modulation of the front-end H-bridge (HB). Since the output power at a certain port in the IDBS-MPET is constrained by the loads at other ports, this paper proposes a multiport steady-state power flow allocation method. This method establishes the load sensitivity correlation factor to enable all the ports to adjust power cooperatively based on it. By applying the proposed steady-state power flow allocation method, iterative calculations continuously update the priority of all the ports and their load sensitivity correlation factors. This process ensures that the power flow converges to a steady-state solution. Simulation results for two different IDBS-MPETs demonstrate that the power flow at all the ports effectively meets load requirements, while the front-end HB avoids over-modulation, ensuring the safe and stable operation of the IDBS-MPET. The results validate the effectiveness of the proposed steady-state power flow allocation method.

Development of a Finite Element Model of the Human Wrist Joint with Radial and Ulnar Axial Force Distribution and Radiocarpal Contact Validation.

This study presents a comprehensive finite element model for the human wrist, constructed from a CT scan of a 68-year-old male (type I wrist). This model intricately captures the bone and soft tissue geometries to study the biomechanics of wrist axial loading through tendon-driven simulations and grasping biomechanics using metacarpal loads. Validation is carried out by assessing the radial and ulnar axial loading distribution, radiocarpal articulation contact patterns, and other standard finite element metrics. The results show radial transmission of the load, consistent with results from wrist finite element models conducted in the last decade and other experimental studies. Our results confirm the model's efficacy in reproducing key known biomechanical aspects, laying the groundwork for future investigations into ongoing wrist biomechanics challenges and pathology mechanism studies.

Non-Linear Biomechanical Evaluation and Comparison in the Assessment of Three Different Piece Dental Implant Systems for the Molar Region: A Finite Element Study.

The widely available options of different manufacturers in dental implant systems have complicated the selection criteria process for periodontists, necessitating careful consideration of various factors when selecting suitable solutions for individual patient needs. Optimal implant selection requires careful consideration of the patient-specific factors, implant design, and surgical technique. Understanding the biomechanical behavior of implant-tissue interactions is crucial for achieving successful and long-lasting implant therapy. To adequately address this issue and improve the rigorous selection criteria from a biomechanically numerical approach, this research aims to analyze the stress distribution fields, strain patterns, and load transfer displacements within the implant system and the implant-biological interface (gingival and bony tissues) of titanium three-piece to two-one-piece ceramic implant systems. Thus, three different commercially available dental implants designed to be placed in the jaw molar region were considered for evaluation through the finite element method under both oblique and occlusal loading conditions. The results have exhibited an increasing trend to highlight the outstanding behavior of two-piece ceramic implants to dissipate the stress distribution better (6 and 2 times lower than the three- and one-piece systems under occlusal loads and almost 5 and 1.3 times more efficient for oblique loading, respectively), minimize peak stress values (below 100 MPa), and reduce strain peak patterns compared with the other two evaluated designs. On the other hand, the effects generated in biological tissues are strongly associated with implant geometry features. This biomechanical approach could provide a promising strategy for predicting micro-strains and micromotion in implant system pieces and geometries. Hence, these findings contribute to a deeper understanding of the biomechanics spectrum in the behavior of dental implant systems and emphasize the importance of carefully selecting appropriate material systems for accurate patient-specific biomechanical performance.

Measurement method of uneven load coefficient for planetary gear trains

The pivotal technical attribute of planetary gear trains lies in their load distribution characteristics. While theoretical studies on planetary gear trains are well-developed, experimental methodologies for accurately measuring uneven load coefficients are lacking. This paper introduces a novel experimental approach that utilizes fan-shaped segmentation of the sun gear to measure these coefficients effectively. Initially, leveraging the kinematic and architectural peculiarities of these systems, the sun gear is meticulously segmented into fan-shaped sections. Subsequently, using planetary gear trains with five and six planetary gears as examples, the experimental protocol comprehensively encompasses sun gear preparation, strain gauge installation, gear wiring, data acquisition, and subsequent processing. Ultimately, the study delves into the influence of torque, rotational velocity, and the count of planetary trains on the uneven load distribution coefficient, thereby furnishing both theoretical and practical insights to underpin the design of planetary gear trains for enhanced operational stability.