The excavator bucket is a primary working component is a primary working component of heavy equipment that is subjected to repetitive static and dynamic loading during operation. Therefore, an adequate structural performance evaluation is required to ensure safety and operational reliability. This study evaluates the stress distribution, displacement, and safety factor of an excavator bucket structure using the Finite Element Method (FEM). A three-dimensional bucket model was developed using FEM-based numerical simulation software, with ASTM A36 structural steel assumed as the material. Static load variations of 196 N, 392 N, and 588 N (converted from 20 kg, 40 kg, and 60 kg using gravitational acceleration of 9.81 m/s²) were applied uniformly to the bucket, while fixed boundary conditions were imposed at the bucket–arm connection. The simulation results show that increasing load levels lead to a significant increase in Von Mises stress and maximum displacement, accompanied by a reduction in the safety factor. The results indicate that under load levels of 392 N and 588 N, the maximum Von Mises stress exceeds the yield strength of ASTM A36 steel (248.23 MPa), indicating plastic deformation and structurally unsafe conditions, the highest load condition indicates that the structure approaches a critical operating state. The results of this study provide a technical basis for evaluating and improving excavator bucket structural design to enhance safety and durability.

To investigate the relationship between the contact site and fracture patterns under static loading using finite element analysis (FEA). Although temporal bone fractures often lead to critical otologic complications, such as hearing loss and facial palsy, their mechanisms are not well understood. Two types of cranial models were developed: a "Simplified model" (S-model) using geometric approximations, and a "Precise model" (P-model) reconstructed from head CT images of a 40-year-old male. Static structural analysis was performed, and static loads were applied to the vertex, left temporal, and occipital regions. First, fracture initiation was estimated from the first principal shear stress, and then fracture propagation paths were predicted from the distribution of the vectors for the first principal stress distribution. S and P-models showed similar stress distribution patterns with some differences; thus, we used the S-model for general mechanical analysis and P-model for anatomically detailed evaluation. Under some loadings, high-stress concentrations were observed at both the contact site and temporal squama. Temporal loading induced stress distributions roughly similar to longitudinal fractures along the petrous ridge. Occipital loading resulted in stress concentration around the foramen magnum, suggesting a correlation with transverse fracture patterns. As an initial simulation effort, the results partially reproduced the clinical correlation between contact site and fracture orientation (longitudinal vs. transverse) under static analysis conditions. This mechanical approach provides a theoretical basis for predicting internal injuries from external trauma. Future refinements incorporating dynamic loading and internal structures are necessary to enhance diagnostic accuracy in emergency situations.

All ceramic dental crowns are widely used in posterior restorations; however, their long-term biomechanical performance remains limited by stiffness mismatch and inadequate stress distribution under functional loading. This study aims to evaluate the biomechanical behavior of zirconia-calcium silicate-silver hybrid crown materials under static and transient dynamic loading conditions and to identify optimal compositions using a multi criteria decision making framework. A three-dimensional finite element model of a crown and tooth with bone system was developed, incorporating nine hybrid compositions (C1-C9) with experimentally derived material properties. Static and transient dynamic loading were applied to simulate physiological mastication. Biomechanical outputs, including von Mises stress and total deformation, were integrated with mechanical properties (hardness, fracture toughness, and elastic modulus) using the TOPSIS method. Results showed that crown stress ranged from 7.46 to 9.78 MPa under static loading and increased to 7.54-10.46 MPa under dynamic conditions (3%-7% increase). Monolithic zirconia exhibited significantly higher stress (up to 19.32 MPa). The periodontal ligament demonstrated a stress reduction of approximately 25%-30% under dynamic loading, indicating its damping role. Deformation remained nearly constant (0.200 mm) across all materials. TOPSIS ranking identified C5 (Ci = 0.777) and C9 (Ci = 0.711) as optimal candidates. The findings demonstrate that hybrid compositions with balanced stiffness improve stress distribution and biomechanical compatibility. The integrated FEA-TOPSIS approach provides a robust framework for optimizing dental restorative materials under realistic loading conditions.

Static performance and failure mechanisms of a rubber-stiffened steel plates with rapid-hardening concrete for sustainable bridge expansion joints retrofitting

Current methods and criteria for defining foot symmetry in biomechanical, clinical, and anthropometric assessments: A systematic review.

Stress-Based biomechanical modeling in hip dysplasia Surgery: A scoping review.

Experimental study on fatigue behavior of CFRP strengthened steel plates subjected to marine environment

Buried rigid box culverts are widely used in transportation and water structures and are often constructed beneath high embankments. Due to the stiffness contrast between the rigid structure and surrounding backfill soil, the soil column directly above the culvert experiences smaller settlement than adjacent soil columns, which may result in stress concentration and increased vertical pressure on the culvert. The induced trench installation (ITI) method was introduced to mitigate this problem by adopting a compressible inclusion above the structure to initiate positive soil arching and redistribute the loads away from the culvert. This study investigates the influence of expanded polystyrene (EPS) geofoam inclusion parameters on the structural behavior of buried rigid box culverts through a series of experimental tests. Eleven reduced-scale laboratory model tests were conducted, including one reference test without EPS and ten tests incorporating EPS inclusions with varying densities, thicknesses, widths, and installation locations. Static surface loading ranging from 20 to 140kPa was applied using a rigid footing system, while vertical pressures within the backfill were monitored using miniature pressure sensors installed above and beside the culvert. The results show that EPS inclusion significantly alters the load transfer mechanism within the backfill and promotes the development of positive soil arching. Among the investigated parameters, EPS thickness had the most pronounced influence on stress reduction, increasing the pressure reduction efficiency from approximately 50% to about 70% as the thickness increased from 2.5cm to 10cm. A lower EPS density also slightly enhanced stress reduction due to its higher compressibility. The findings demonstrate that properly configured EPS geofoam inclusions can effectively reduce vertical stresses acting on buried rigid culverts and improve their structural performance under embankment loading conditions.

The present study investigates the structural performance of uniformly tapered hollow roller (UTHR) and uniformly tapered layered hollow roller (UTLHR) bearings with varying hollowness levels using finite element analysis (FEA) and experimental validation. A comprehensive numerical investigation was conducted for hollowness levels ranging from 30% to 80% to evaluate maximum deflection, bending stress, von Mises stress, contact pressure, endurance-limit loading, and radial stiffness. The finite element results identified an optimum hollowness range of approximately 31-40%, where stress redistribution was achieved without excessive loss of stiffness. The analytical study predicted applied radial load of 30 kN, with a deviation of 0.1412%, which is validating the theoretical formulations. Moreover, simulations results realized reduced stress concentrations and optimized stiffness at optimum hollowness. The layered hollow roller configurations dominate over single hollow roller design in terms of lower contact pressure and improved stress distribution. The experimentally measured static failure loads were 53.01 kN and 76.17 kN for the UTHR and UTLHR bearings, respectively. The experimental results showed excellent agreement with the finite element predictions, with deviations below 2.5%. Accordingly, the effective similarities between the predicted and experimental results shows the reliability of the adopted modelling approach and highlights the structural advantages of layered hollow rollers within an optimized hollowness range.

Biomechanical evaluation of fixation techniques for isolated Letenneur Type I lateral Hoffa fractures: A cadaveric model.

The glenoid concavity and the compression applied by the rotator cuff (RC) are essential for glenohumeral stability (GHS). This study aimed to determine how different simulated rotator cuff tears (RCT) and the glenoid depth influence GHS. A Load and Shift sequence was performed with eight fresh-frozen cadaveric shoulders in a robotic-assisted setup. Differently configured static loading of the reinforced RC and deltoid muscle (DLT) simulated intact RC and anterior, superior, anterosuperior, posterosuperior, mass, and complete RC plus DLT tears. Anterior dislocation forces and their changes were determined as indicators of stability. The glenoid depth and Bony shoulder stability ratio (BSSR) were defined as indicators of concavity. To assess GHS, the maximal force (Favg), the maximal force increase (dFavg), and their mean deviations (ΔFmax, ΔdFmax) to the intact configuration during the sequence were evaluated. Simulated tears of the subscapularis tendon (SCP) (ΔFmax = 7.90N, ΔdFmax = 1.54N/mm) and simulated tears of the infraspinatus (ISP) + teres minor (TM) tendons (ΔFmax = 7.19N, ΔdFmax = 1.48N/mm) resulted in greater differences to the intact shoulder than simulated tears of the supraspinatus tendon (ΔFmax = 3.82N, ΔdFmax = 1.16N/mm). High correlations were observed between maximal force concerning glenoid depth (r = 0.81) and BSSR (r = 0.79). Simulated tears of the SCP or ISP + TM significantly affect the anterior GHS in this model. These findings highlight the importance of careful evaluation regarding the indication for surgical reconstruction in such configurations. Decreased glenoid concavity reduces the anterior GHS and should be considered in treatment algorithms for shoulder instability. Controlled Laboratory Study. IV.

In addition to static loads, structural glazing joints in glass and facade construction are increasingly exposed to dynamic and extraordinary loads such as earthquakes. Recent studies have highlighted a significant influence of the test frequency on the low-cycle fatigue (LCF) performance of structural adhesives, but a consistent modeling approach is still lacking. This study investigates the frequency-dependent fatigue behavior of structural glazing joints under seismic loading conditions. To evaluate the frequency influence in detail, 112 specimens were subjected to force- and displacement-controlled LCF tests. These two control modes represent different boundary conditions and failure mechanisms relevant to typical glass and facade constructions. For the displacement-controlled tests, specific failure criteria based on cyclic parameters were defined to ensure comparability. The results confirm a clear frequency dependency with higher frequencies leading to longer fatigue life until complete failure. To capture this effect, the conventional Basquin-type S-N approach was extended by incorporating the test frequency as an additional influencing factor. The modified model showed very good agreement with the experimental data across all configurations. These findings contribute to the understanding of the frequency -dependent fatigue failure mechanisms in structural glazing joints and support the improvement of design concepts under seismic loading.

Human skin efficiently perceives tactile stimuli through specialized mechanoreceptors strategically arranged around the papillary structure at the epidermis-dermis junction. Here, we demonstrate a cooperative self-powered multimodal tactile sensor that mimics both the spatial organization and mechanical functionality of Merkel discs (SA1) and Meissner corpuscles (RA1) within an artificial papillary architecture. The artificial Meissner sensor generates rapid-adapting responses under slip, while the Merkel sensor produces sustained slow-adapting outputs under static loading. The modulus contrast between a rigid epidermal layer and a soft dermal layer induces localized stress concentration and, importantly, mechanically filters incoming stimuli by selectively amplifying periodic components. This structural filtering enhances targeted stress delivery and signal amplification compared to sensors without papillary structure, resulting in over 1.5-fold improvement in pressure sensitivity for Merkel sensor and more than two orders of magnitude enhancement in amplitude with improved frequency-domain clarity for Meissner sensor. Combined with fingerprint-inspired microstructures and machine learning, the system achieves 97.5% classification accuracy across 12 fabric-shape combinations and enables tactile regeneration of embossed patterns. This bioinspired platform provides a structural strategy for enhancing multimodal tactile perception in electronic skin and robotics.

Faced with the challenges of high in-situ stress and elevated rockburst risk in isolated working faces within fold zones, this study takes an isolated working face in a specific coal mine as the engineering background. By integrating theoretical analysis, numerical simulation, and field practice, we investigated the evolutionary characteristics of overlying strata structure, clarified the variation law of mining-induced stress, revealed the rockburst mechanism of isolated working faces in fold zones of extra-thick coal seams, and established a dynamic risk identification model for the working face.The results show that when the minimum width of the coal pillar (95m) during mining in the fold zone is significantly larger than the critical width (36.5m), the overlying strata of the working face form a unique long-arm "F" structure. The cantilever effect of this structure causes the peak stress of the coal-rock mass in the working face advance area to increase to 42.1MPa, with a stress concentration factor of 2.34. The superposition of the high static load in the advance area and the intense dynamic load released by the fracturing of the "F" structure leads to a significant decrease in the minimum principal stress and a corresponding increase in the maximum principal stress. This pushes the coal-rock mass beyond its strength limit, ultimately triggering a rockburst.To address the limitation of low early-warning accuracy (81.4%) associated with traditional single-index methods, a multi-index collaborative identification model based on microseismic data was constructed. Utilizing a Back-Propagation (BP) neural network algorithm, the model adaptively optimizes the coupling weights of six key indicators: b-value (0.04), P(b)-value (0.009), ∆F-value (0.185), AC-value (0.218), EEM-value (0.256), and S-value (0.292). This realizes a paradigm shift from "single-index alarm" to "multi-index collaborative discrimination". Field validation demonstrates that the model improves the early-warning accuracy to 94.9%, significantly enhancing the capability for dynamic risk identification of rockbursts in the working face. The research conclusions provide a valuable reference for the safe mining of isolated working faces under similar geological and mining conditions.

AimUnderstanding the physical and physiological demands of female youth basketball is essential for optimizing training and performance monitoring. However, evidence describing match demands in elite U-19 female players, particularly in African contexts, remains limited. Existing profiles are largely derived from male or adult cohorts and may not accurately reflect youth competition. This study aimed to examine the physical and physiological demands of elite North African U-19 female basketball players, considering differences by playing position (guards, forwards, centers) and competitive level (national vs. international).MethodsThirty elite Tunisian U-19 female players (age 18.3 ± 0.2 years, height 1.78 ± 0.05 m, mass 82.9 ± 4.8 kg; 15 national-level, 15 international-level) were monitored during eight playoff games. Video-based time-motion analysis quantified activity frequency and duration across nine movement categories (standing, walking, jogging, running, sprinting, jumping, low/moderate/high-intensity shuffling). Physiological responses included heart rate (HR) monitoring (four intensity zones: <75%, 75–85%, 85–95%, >95% HRmax) and capillary [La] sampling. Two-way ANOVA (position × level) examined main and interaction effects.ResultsInternational-level players performed significantly more high-intensity activities than national-level players (224.0 ± 5.1 vs. 214.1 ± 5.4; p < 0.001, d = 1.95) and spent more time in maximal HR zones (16.1 ± 0.3% vs. 12.1 ± 0.3%; p < 0.001, d = 13.33), indicating greater fatigue resistance. Guards executed more high-intensity shuffling actions than forwards and centers (p < 0.001, η2 = 0.92), whereas centers performed more static high-intensity actions and exhibited higher [La] concentrations (5.22 ± 0.15 vs. 4.93 ± 0.13 and 4.64 ± 0.12 mmol L−1; p < 0.001, η2 = 0.76). High-intensity activity declined from the first to the fourth quarter in both groups (p < 0.001, η2 = 0.94), with a greater reduction in national-level players (37.0% decline) than international players (31.9% decline). Intra-observer reliability was excellent across all movement categories (ICC ≥ 0.91; CV ≤ 4.6%).ConclusionU-19 female basketball imposes distinct position-specific demands (guards: high-intensity lateral movements; centers: static exertions and elevated metabolic load) and competitive-level differences (international players: superior fatigue resistance). These findings provide the first quantitative profile of elite African female youth basketball, establishing reference benchmarks for position-specific conditioning and competitive-level progression assessment.

Total sacrectomy is now a standard curative procedure for primary malignant sacral tumours. Reconstruction, however, remains demanding because of the complex regional anatomy and unique biomechanical environment. Several spinopelvic reconstruction techniques have been reported, all yielding satisfactory functional outcomes. This study aims to evaluate both the clinical outcomes and the biomechanical behavior of a modified spinopelvic fixation construct, which incorporates a novel three-dimensional-printed component following total sacrectomy. We conducted a retrospective cohort study of 12 consecutive patients (4 men, 8 women; mean age 38 years, range 17-61 years) treated between 2021 and 2024. Eleven patients with primary malignant sacral tumours underwent total en-bloc sacrectomy, and one patient with a giant-cell tumour (GCT) underwent piecemeal resection. All patients received modified spinopelvic reconstruction. Tumour extent was L5-S5 in two patients with recurrent malignant peripheral nerve sheath tumour (MPNST), S1-S5 in eight patients with primary malignancies, S1-S5 in the patient with GCT, and S1-S5 with extension into pelvic zones I/IV in one patient with osteosarcoma. Operative time, oncological outcomes, functional outcomes, complications, and implant status were all reviewed. A finite-element analysis was performed to evaluate the biomechanical behaviour of the novel construct and to compare it with previously described reconstruction models. All 12 patients had a confirmed histological diagnosis before surgery. Three osteosarcoma and four malignant peripheral nerve sheath tumour (MPNST) patients received neoadjuvant and postoperative chemotherapy; one giant-cell tumour (GCT) patient was treated with denosumab. Mean operative time was 11.5h (range 7.5-15h) and mean intra-operative blood loss was 2,616ml (range 1,200-4,000ml). During follow-up, local recurrence was detected in two chordoma cases. Functionally, S1-S5 root transection caused sphincter disturbance in 11 patients; two of these also sacrificed a unilateral L5 root, yet none required colostomy or chronic catheterisation. Nine patients lost dorsiflexion strength. At the latest follow-up, 10 patients could walk independently, and 2 required assistive devices. No major perioperative complications were observed; three patients experienced wound healing complications, which were successfully managed with simple debridement, suturing, and negative pressure wound therapy. Only one overweight patient experienced unilateral iliac screw failure without further revision; the remaining 11 patients had no mechanical complications. Finite-element analysis suggested that the current reconstruction may have favorable load-bearing capacity and stability characteristics compared with previously described models. The modified spinopelvic fixation with the fifth rod and 3D-printing element represents a potential option for anterior column reconstruction after total sacrectomy, with preliminary evidence of satisfactory clinical outcomes in non-overweight patients. Finite-element analysis suggests that the construct may possess adequate stiffness and stability characteristics that could contribute to preventing pelvic-spinal collapse, though these biomechanical findings require further clinical validation. Stress values from the finite-element model indicate a theoretically low risk of implant fracture under static loading or fatigue conditions, but long-term follow-up is necessary to confirm implant durability and exclude late complications such as loosening or breakage.

Türkiye is home to numerous historical masonry structures that reflect its rich cultural heritage. Understanding the structural behavior of such buildings under various loading conditions is crucial for identifying damage mechanisms and supporting effective conservation strategies. While previous studies have primarily focused on the effects of earthquakes, the impact of continuous vertical loads, such as gravity and snow, has been relatively overlooked. This study investigates the structural behavior of the St. Bartholomeus Church under static and dynamic loading conditions. After conducting material characterization and structural assessments, three-dimensional finite element model was developed using SAP2000 v20 and ANSYS v19 to identify the difference in the results. The structure was analyzed under its own weight, snow load, and seismic excitations to evaluate its response and identify potential sources of damage. The results indicate that the structure exhibits significant tensile and shear stress concentrations even under its own weight. When snow loads are included, these stress levels increase significantly, particularly in the roof and west wall. This suggests that damage could initiate under vertical loading conditions. Seismic effects could further exacerbate these effects and contribute to the progression of damage. These findings indicate that dead and snow loads can significantly contribute to the deterioration of abandoned historical masonry structures, and that these factors must be considered alongside seismic effects in structural assessments. Accordingly, structural reinforcement measures may be necessary to enhance stability and resilience, particularly in the event of a future earthquake.

Tooth-supported fixed partial dentures (FPDs) exhibit complex biomechanical behaviour because occlusal loads are transferred through the periodontal ligament (PDL) and heterogeneous mandibular bone. This pilot study aimed to develop a patient-specific NURBS-based finite element analysis (FEA) workflow for anatomically realistic mandibular reconstruction and to evaluate the biomechanical effect of geometric simplification in tooth-supported FPD simulations. Cone beam computed tomography data from a single subject were segmented and reconstructed into a layered three-dimensional model of the mandible and dentition, including cortical bone, cancellous bone, teeth, and PDL. A high-fidelity reference model (V0) and four simplified variants (V1-V4) were analysed under static 500 N loads applied at 0° and 30°. The reference model yielded a maximum von Mises stress of 507 MPa and a peak displacement of 0.74 mm, with stress concentrations consistently localised at the retainer-pontic connector region. Inclusion of the PDL markedly affected the mechanical response, doubling denture displacement in simplified comparative models. Among the simplified configurations, V4, which preserved cortical morphology and PDL representation while omitting detailed trabecular architecture, showed the closest agreement with the reference model, with mean deviations of 6.1% and 5.8% under the two loading conditions, respectively. These findings suggest that patient-specific NURBS-FEA modelling provides a robust framework for biomechanical assessment of tooth-supported FPDs, while controlled simplification may improve computational efficiency without substantially compromising accuracy under static loading conditions.

Complex craniocervical malformations pose significant challenges to surgical fixation. The biomechanical advantage of occipital plate fixation versus short-lever modified C1 lateral mass screw fixation remains controversial, and finite element analysis (FEA) is a reliable tool for implant performance evaluation. To compare biomechanical characteristics of occipital plate fixation and modified C1 lateral mass screw fixation in AOZ-BI and AOZ-AAD models via FEA, and guide surgical decision-making. A validated healthy occipito-atlantoaxial (C0-C2) FEA model was established using CT data. Two pathological models were constructed: AOZ-BI (Group A, atlantoaxial distance [ADI] < 5mm) and AOZ-AAD (Group B, ADI ≥ 5mm with transverse ligament dysfunction), each divided into occipital plate and modified C1 lateral mass screw subgroups. Static loads (40N preload + 1.5N·m torque) simulated flexion (Fe), extension (Ex), lateral bending (LB), and axial rotation (AR). C1-C2 range of motion (ROM) and screw-rod peak Von Mises stress (PVMS) were measured. Modified C1 lateral mass screw fixation reduced C1-C2 ROM by 19.67% (flexion-extension) to 48.51% (lateral bending) compared with occipital plate fixation. In flexion/extension/axial rotation, C1 lateral mass screw fixation increased screw-rod peak Von Mises stress (PVMS) by 51.17%-131.37% in the AOZ-BI group and 36.51%-56.02% in the AOZ-AAD group; in lateral bending, PVMS decreased by 19.46% in the AOZ-BI group but increased by 5.24% in the AOZ-AAD group. occipital plate fixation consistently had higher ROM (Group B highest) but lower PVMS. Modified C1 lateral mass screw fixation provides superior C1-C2 stability for AOZ-associated BI-AAD but increases implant stress in Fe/Ex/AR. Occipital plate fixation is less stable but reduces stress. Clinically, C1 lateral mass screw is preferred for AOZ-BI; AOZ-AAD requires balancing stability and stress risk. Occipital plate suits patients with severe C1 lateral mass hypoplasia. FEA effectively evaluates craniocervical fixation biomechanics.

Restoration of root canal-treated teeth presenting with apical lesions requires careful selection of post-materials because their mechanical properties influence stress transfer within dental and supporting structures. This study aimed to evaluate, using finite element analysis, stress distribution patterns in a mandibular premolar with root canal treatment and an apical lesion restored with fiber, cast metal, or zirconia post systems supporting a three-unit bridge under occlusal loading. Four 3D finite element models were developed: a healthy premolar reference model and three lesioned premolar models restored with fiber, cast metal, or zirconia posts integrated into a three-unit fixed prosthesis. A static occlusal load of 300 N was applied at 45 degrees to the long axis of the tooth on the lingual incline of the buccal cusp. Deformation behavior and equivalent stress (von Mises) distributions were computed across dental tissues, prosthetic components, and surrounding bone structures. Occlusal loading generated consistent stress concentration patterns across models, predominantly in the buccal cervical region, the load-application cusp, and the cervical and middle thirds of the root, with intensified stresses at prosthetic connector regions. Posts with higher elastic moduli retained stresses within the post structure and reduced transmission to dentine, whereas fiber posts promoted more homogeneous stress distribution into surrounding dental tissues. These findings indicate that elastic compatibility influences load transfer pathways within structurally compromised abutment teeth. Within the limitations of this computational study, higher-modulus post systems localized stresses within the post, whereas lower-modulus fiber posts redistributed stresses to dentine, demonstrating that post-material selection significantly affects biomechanical response in lesioned teeth supporting fixed prostheses.