Stability Of Plates Research Articles

On static and dynamic stability of bio-inspired composite plates under variable axial load

On static and dynamic stability of bio-inspired composite plates under variable axial load

A polyolefin separator reinforced inorganic/organic composite electrolyte for quasi-solid-state Lithium-sulfur batteries with high cycle stability and long lifespan

Lithium-sulfur (Li-S) batteries are considered a promising next-generation energy storage system due to the high energy density and the low cost. However, the severe shuttle effect of polysulfide and the security issue caused by organic liquid electrolyte and lithium metal anode have hindered their commercial application. Herein we achieved a polyolefin commercial separator reinforced inorganic/organic composite electrolyte (denoted as Com-LATP) via coating the polypropylene (PP) separator with the composite of polymethyl methacrylate/poly(vinylidene fluoride) (PMMA/PVDF) modified with Li1.3Al0.3Ti1.7(PO4)3 (LATP). The Com-LATP electrolyte (thickness: ∼30 um) exhibits remarkable tensile strength of 103 MPa, an ionic conductivity of 0.47·mS cm-1 with the Li+ transfer number of 0.45, which is beneficial for the uniform Li+ flux and the stable striping and plating of Li metal. The Li symmetrical batteries equipped with this Com-LATP exhibited stable cycling for over 350 h. Meanwhile, the Com-LATP electrolyte with the special dense structure can hinder the polysulfide diffusion. The developed quasi-solid-state lithium-sulfur batteries have demonstrated impressive cycling stability with an initial specific capacity of 1184.8 mA h g-1 at a discharge rate of 0.2 C, maintaining performance over 200 cycles. Additionally, they exhibited outstanding rate capability, retaining a reversible capacity of 710.4 mA h g-1 even at a higher discharge rate of 2 C. This research introduces an innovative structural design approach for high-performance quasi-solid-state Li-S batteries, which holds significant promise for advancing the commercialization of lithium-sulfur battery technology.

Angular stable plate fixation provides favorable biomechanical stability in simulated T-shaped acetabular fractures: a biomechanical study.

The treatment of acetabular fractures remains technically demanding. In the case of reduced bone quality or fracture morphology reducing the amount of bone available for fixation, locking plates should provide considerable advantages. The aim of the present study was to compare conventional and locking plate fixation. It was hypothesized that locking plate fixation provides less displacement and higher construct stiffness. A T-shaped acetabular fracture was simulated in 16 synthetic pelvic models. The fracture was addressed with a biplanar 10-hole 2-column plate buttressing the medial acetabular wall. Optical markers were attached to the fracture sites for motion tracking. Standardization of the acetabulum loading mechanism was performed using a unipolar hemiarthroplasty. The primary outcome measure was displacement at the fracture sites. The secondary outcome measure was the construct stiffness (N/mm). Fracture displacement was less in the group of angular stable implants compared with the group fixed with conventional non-locking implants. Under cyclic loading displacement was less in the group of locking plate fixation. No differences in mean initial axial stiffness were detected between locking plate fixation (407 N/mm) and conventional plating (308 N/mm, ∆ 99 N/mm, 95% confidence interval -48 to 245). We showed that locking plate fixation buttressing the medial acetabular wall achieved less fracture displacement but showed no differences in axial stiffness compared with conventional plating.

Cold Sintering Halide-in-Oxide Composite Solid-State Electrolytes with Enhanced Ionic Conductivity.

All-solid-state batteries (ASSBs) have attracted increasing attention for next-generation electrochemical energy storage due to their high energy density and enhanced safety, achieved through the use of nonflammable solid-state electrolytes (SSEs). Oxide-based SSEs, such as Li1.3Al0.3Ti1.7(PO4)3 (LATP), are notable for their high ionic conductivity and excellent chemical and electrochemical oxidation stability. Nevertheless, their brittle mechanical properties and poor interface contact with electrode materials necessitate high-temperature and long-duration sintering or postcalcination processes, limiting their processability for real-world applications. Additionally, the formation of secondary phases can detrimentally affect the ionic conductivity of LATP electrolytes. Emerging halide-based SSEs offer reliable deformation for practical processing while maintaining high ionic conductivity. In this work, we report a transient liquid-assisted cold sintering process to integrate oxide-based LATP as the matrix and halide-based Li3InCl6 as the conductive boundary phase into a halide-in-oxide ceramic composite electrolyte at a low processing temperature of 150 °C. This composite structure significantly reduces interface resistance, effectively addressing ion-transport depletion across the boundaries between LATP particles. Consequently, the cosintered LATP-Li3InCl6 composite SSE exhibits a high ionic conductivity of 1.4 × 10-4 S cm-1 at ambient temperature. Furthermore, the symmetric Li|LATP-Li3InCl6·nDMF|Li cell demonstrates stable stripping and plating processes for 1600 h at 55 °C (0.1 mA cm-2) and 1200 h at 100 °C (1 mA cm-2). This work represents the first demonstration of halide-oxide ceramic composite SSEs that combine the advantages of oxides and halides for high-performance SSBs.

Skill-Learning-Based Trajectory Planning for Robotic Vertebral Plate Cutting: Personalization Through Surgeon Technique Integration and Neural Network Prediction

In robotic-assisted laminectomy decompression, stable and precise vertebral plate cutting remains challenging due to manual dependency and the absence of adaptive skill-learning mechanisms. This paper presents an advanced robotic vertebral plate-cutting system that leverages patient-specific anatomical variations and replicates the surgeon’s cutting technique through a trajectory parameter prediction model. A spatial mapping relationship between artificial and patient vertebrae is first established, enabling the robot to mimic surgeon-defined trajectories with high accuracy. The robotic system’s trajectory planning begins with acquiring point cloud data of the vertebral plate, which undergoes preprocessing, Non-Uniform Rational B-Splines (NURBS) fitting, and parametric discretization. Using the processed data, a spatial mapping method translates the surgeon’s cutting path to the robotic coordinate system, with simulation validating the trajectory’s adherence to surgical requirements. To further enhance the accuracy and stability of trajectory planning, a Backpropagation(BP) neural network is implemented, providing predictive modeling for trajectory parameters. The analysis and training of the neural network confirm its effectiveness in capturing complex cutting trajectories. Finally, experimental validation, involving an artificial vertebral body model and cutting trials on patient vertebrae, demonstrates the proposed method’s capability to deliver enhanced cutting precision and stability. This skill-learning-based, personalized trajectory planning approach offers significant potential for improving the safety and quality of orthopedic robotic surgeries.

Palmar Plate Fixation in Scaphoid Nonunions—Surgical Technique and Review of the Literature

AbstractEven today, the treatment of scaphoid nonunions remains challenging for the treating hand surgeon. Considering the biomechanical principles of wrist kinematics, especially the three-dimensional movement of the scaphoid, it is evident that a single headless compression screw does not provide sufficient stability to counteract all these forces, particularly rotational forces. Palmar plate fixation was initially introduced as a salvage procedure after failed screw fixation. It ensures very high rotational stability but also supports correction of the humpback deformity, reconstruction of scaphoid length, and prevents bone graft extrusion. However, indications have since been extended to include primary nonunion treatment in cases with humpback deformity or comminuted fractures. Even in recalcitrant cases (substantial bone loss, prior surgery failure, avascular necrosis, or durations exceeding 2 years), high union rates and favorable functional outcomes have been reported. This article attempts to summarize the biomechanical principles, indications, surgical techniques, and results following palmar angular stable plate fixation in scaphoid nonunions.

Factors Influencing the Success of Non Vascularized Iliac Bone Graft for Mandibular Reconstruction: A Retrospective Study of 26 Cases

Objective: This study aimed to identify the prognostic factors influencing the success of nonvascularized iliac bone grafts for mandibular reconstruction. Methods: This was a retrospective cohort study conducted at a single center, involving 26 patients who underwent segmental mandibulectomy followed by nonvascularized iliac bone grafts between 2012 and 2022 at the Oral and Maxillofacial Surgery Unit, Buddhachinaraj Phitsanulok Hospital. Data were collected by reviewing electronic medical records and radiographic images. Patients who had received vascularized bone grafts or had a history of head and neck irradiation therapy were excluded from the study. The patients were classified into two groups: successful and failed. Success was defined as clinical and radiographic evidence of bone continuity, a graft resorption rate not exceeding 30% of the initial height, and no evidence of chronic infection for at least 6 months. Results: Successful bone grafting was achieved in 19 patients (73.1%). Multivariable risk difference regression analysis identified that the factors influencing graft incorporation were jaw immobilization using reconstruction plates with maxillomandibular fixation for at least 21 days (RD 63.0; 95% CI 33.1, 93.0; p<0.001) and long segmental block graft design (51.3%; 95% CI 16.9, 85.7; p<0.003). A clinically significant factor, although statistically insignificant, was the duration of plate stabilization, which should ideally range from 172 to 232 days prior to plate removal. The sample size constituted a limitation of this study. Conclusions: Nonvascularized bone grafting remains a viable option for reconstructing mandibular segmental defects. The factors influencing graft stability can help improve clinical outcomes.

Three-Layered Annular Plate Made of Functionally Graded Material Under a Static Temperature Field.

The presented problem considers the static temperature analysis of a three-layered, annular plate with heterogeneous facings made of material with radially variable parameters. They are defined by the accepted exponent functions. The plate is composed of thin metal facings and a thicker foam core. The plate is loaded with a flat temperature field with a gradient directed across the plate radius. Using the approximation finite-difference method, the eigen-value problem is solved in order to calculate the temperature differences between plate edges, which cause a loss of plate stability. Taking into account the different material and geometrical parameters, the critical temperature state parameters are evaluated. The meaning of the mixed system of parameters connected with the plate shape geometry, dimensions of the plate-transversal structure, and with the gradation of the material in the radial direction on the thermal response of the composite plate have been found. Numerous results of numerical calculations show the responses of the examined composite plate with facings made of the heterogeneously directed material.

The Rising Popularity of Growth Hormone Therapy and Ensuing Orthopedic Complications in the Pediatric Population: A Review.

The utilization of recombinant human growth hormone therapy in pediatric populations, originally approved to treat diseases of growth hormone deficiency, has expanded to encompass a broader range of indications, leading to a threefold increase in its utilization in the last two decades. However, concerns regarding its safety, particularly those that are orthopedic in nature, have grown alongside its increasing popularity. Growth hormone usage has been reported to predispose patients to a multitude of common orthopedic conditions, including carpal tunnel syndrome, Legg-Calve-Perthes disease, little league shoulder, Osgood-Schlatter disease, osteochondritis dissecans, scoliosis, Sever's disease, and slipped femoral capital epiphysis. The pathways by which growth hormone therapy can precipitate orthopedic pathology has been shown to be multifactorial, involving mechanisms such as hormonal changes, growth plate instability, rapid growth, and increased susceptibility to overuse injury. This review examines the orthopedic consequences of growth hormone therapy in pediatric patients by discussing these potential pathophysiologic mechanisms of injury and analyzing subsequent clinical manifestations. By examining processes underlying these complications, we highlight the need for orthopedic surveillance and management in children receiving GHT, particularly those with pre-existing musculoskeletal comorbidities or high levels of physical activity. Our findings underscore the importance of a multidisciplinary approach involving co-management by pediatricians, endocrinologists, and orthopedic surgeons to optimize safety and outcomes for these patients. Directions for future research include correlating pathophysiologic mechanisms to injury patterns, investigating long-term complications in recently approved growth hormone therapy indications, and informing clinical guidelines on the management of orthopedic injuries in this patient population.

Evaluation of the biomechanical effects and stability of titanium and carbon fiber-reinforced polyetheretherketone mini plates in Le Fort I advancement osteotomy fixation using finite element analysis

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

New insights into the crustal structures of the Arabian Plate and surrounding plates unveiled from the crustal thickness model and its implications for geodynamics

Geodynamics of the Arabian Peninsula is less understood as crustal structures are not well delineated due to uneven distribution and lack of seismic measurements and ground based geophysical data in the Arabian interior. To address this, we delineated crustal structures in the Arabian Peninsula through the creation of a crustal thickness model from the inversion of GOCO60s gravity field model, which revealed details on the underlying crustal structures. Our model revealed strong crustal thickness variations in the Zagros fold belt that indicates high deformational history and crustal reworked, which also reflect directional collisional events between the Arabian and Eurasian Plates, similar to the Himalaya type as the result of mantle processes. The resolved crustal structures also reveal a relatively slow rifting process on the southern end of the Red Sea than at the northern end, which resulted in the bulging of crust in the southern part of Zagros Fold Mountains. Further, folding and bulging of crustal structures is more intense near the Arabian Platform and slower on the Eurasian side, which could indicate a relatively stable Eurasian plate compared to the geodynamically active Arabian Plate. Overall improvement in our high-resolution crustal thickness model yields an improved representation of crustal structures over previously derived models of the Arabian Peninsula and the Surrounding plates that indicates a variation in the Proterozoic crust in Arabian Plate, possibly indicating a secular variation in the crustal structure.

Does minimally invasive external fixation of proximal humerus fractures provide adequate stability? A biomechanical in vitro study

IntroductionProximal humerus fractures are usually treated with rigid angle-stable plates or nails. As an alternative, semi-rigid, minimally invasive systems have been developed for supportive fixation. A new system uses this principle with 2.5 mm partially threaded pins and external fixation.AimThis study aimed to compare the fracture stability of the fixator with an angular stable plate about whether the mechanical stability is sufficient for early postoperative mobilisation.Materials and methodsHuman proximal humeri (paired, female, age ≥ 60, n = 8) were cut to a 3-part fracture and treated with an external fixator (Galaxy Shoulder, Orthofix) or an angular stable plate (Philos, DePuy Synthes). A physiological load was simulated in vitro based on a 45° abduction motion. The load level was continuously increased from 10 to 320 N within 10,000 cycles simulating the loads during rehabilitation. This was followed by another 10,000 cycles at 320 N for fatigue testing. Fracture motion was recorded with a 3D camera. Fracture stability was evaluated at a partial load of 160 N and 240 N (simulating loads during early mobilisation).ResultsThe fracture motion at the lateral aspect was significantly (p < 0.034) larger for the fixator compared to the plate both for axial and for shear movements, while at the medial aspects fracture motions were similar. Both fixation systems adequately stabilized the lateral tubercle fragment with no significant differences between fixation techniques. The migration of the fixator pins (1.1 ± 1.0 mm) and valgus rotation of the head fragment were minimal (3.1 ± 2.0°). The maximum load level of 320 N was reached by all plate constructs and 3 fixator constructs.ConclusionOur results suggest that the external fixator system allows early but gentle postoperative mobilisation. More aggressive rehabilitation measures should be postponed after the healing of the fracture.

Study on the buckling behavior of aluminum alloy sheets - before and after repaired with composite patches

In this paper, the compressive buckling behavior of aluminum alloy plates with an elliptical hole of various sizes is investigated. In order to improve the stability of these thin plates, T700/QY8911 composite laminate is used as a patch to repair the hole. The study included an analysis of the critical and post-critical behaviour using experimental and numerical methods. Experiments focus on buckling loads, post-buckling behavior and the relationship between sizes of holes and buckling load. Meanwhile, the buckling load and buckling mode are determined by finite element analysis, using linear analysis of eigenvalue problems modes, and then, the nonlinear analysis of structures with initiated geometrically imperfection is carried out, studying its post-buckling behavior, damage behavior and transfer of load. The results show that the buckling load of the open-hole specimen is related to size of opening. The existence of patch has a significant influence on stress distribution, and the buckling capability of repaired specimens is noticeably improved to the plate without a hole. And the compression experimental results are consistent with the numerical results, revealing that the developed finite element model of the structure is correct.

Inkjet-Printed Silver Lithiophilic Sites on Copper Current Collectors: Tuning the Interfacial Electrochemistry for Anode-Free Lithium Batteries

Anode-free lithium batteries (AFLBs) present an opportunity to eliminate the need for conventional graphite electrodes or excess lithium–metal anodes, thus increasing the cell energy density and streamlining the manufacturing process. However, their attributed poor coulombic efficiency leads to rapid capacity decay, underscoring the importance of achieving stable plating and stripping of Li on the negative electrode for the success of this cell configuration. A promising approach is the utilization of lithiophilic coatings such as silver to mitigate the Li nucleation overpotential on the Cu current collector, thereby improving the process of Li plating/stripping. On the other hand, inkjet printing (IJP) emerges as a promising technique for electrode modification in the manufacturing process of lithium batteries, offering a fast and scalable technology capable of depositing both thin films and patterned structures. In this work, a Fujifilm Dimatix inkjet printer was used to deposit Ag sites on a Cu current collector, aiming to modulate the interfacial electrochemistry of the system. Samples were fabricated with varying areas of coverage and the electrochemical performance of the system was systematically evaluated from bare Cu (non-lithiophilic) to a designed pattern (partially lithiophilic) and the fully coated thin film case (lithiophilic). Increasing lithiophilicity resulted in lower charge transfer resistance, higher exchange current density and reduced Li nucleation overpotential (from 55.75 mV for bare Cu to 13.5 mV for the fully coated case). Enhanced half-cell cyclability and higher coulombic efficiency were also achieved (91.22% CE over 76 cycles for bare Cu, 97.01% CE over 250 cycles for the fully coated case), alongside more uniform lithium deposition and fewer macroscopic irregularities. Moreover, our observations demonstrated that surface patterning through inkjet printing could represent an innovative, easy and scalable strategy to provide preferential Li nucleation sites to guide the subsequent Li deposition.

Pt-Ta microhotplate with low resistance temperature coefficient and low resistance drift

Micro thermal plates are widely used in various sensors in the aerospace and automotive fields. With the reduction of chip size and the development of MEMS, micro thermal plates are also moving towards integration. The device failure caused by the Pt film at high temperatures seriously affects the stability of the sensor, and degradation determines the sensor's operating temperature and service life. In this paper, Pt, Pt-Ta, and Pt-Pd microcalorimetric plates were prepared and analyzed for their sintering behavior, microstructure, electrical properties, and high-temperature stability using co-firing of resistors and alumina substrates. The film layers prepared by co-firing were better matched to the alumina substrate, and the sintered network of the film layers was better. The Pt-10 %Ta microthermal plate has a 46 % lower resistance temperature coefficient TCR compared to the Pt microthermal plate, and the resistance drift at 800°C is reduced to 2.11 %/Day. And even at 1100°C, the Pt-Ta system also has a very low resistance drift −12 %/Day (Pt26.6 % /Day and Pt-Pd35.18 %/Day) with improved high temperature stability. The addition of Ta allows the membrane layer to have fewer voids at high temperatures, reinforcing the high temperature characteristics of the resistance thermometer. It improves the stability and accuracy of the heating plate in high temperature gas sensor applications.

Finite element analysis and optimization studies on tibia implant of SS 316L steel and Ti6Al4V alloy

Tibial fractures account for approximately 15% of all fractures, typically resulting from high-energy trauma. A critical surgical approach to treat these fractures involves the fixation of the tibia using a plate with minimally invasive osteosynthesis. The selection and fixation of the implant plate are vital for stabilizing the fracture. This selection is highly dependent on the plate's stability, which is influenced by factors like the stresses generated in the plate due to the load on the bone, as well as the plate's length, thickness, and number of screw holes. Minimizing these stresses is essential to reduce the risk of implant failure, ensuring optimal stress distribution and promoting faster, more effective bone healing. In the present work, the finite element and statistical approach was used to optimize the geometrical parameters of the implant plate made of SS 316L steel and Ti6Al4V alloy. A 3D finite element model was developed for analyzing the stresses and deformation, and implant plates were manufactured to validate the results with the help of an experiment conducted on the universal testing machine. A strong correlation was observed between the experimental and predicted results, with an average error of 8.6% and 8.55% for SS316L and Ti6Al4V alloy, respectively. Further, using the signal-to-noise ratio for the minimum stress condition was applied to identify the optimum parameters of the plate. Finally, regression models were developed to predict the stresses generated in SS316L and Ti6Al4V alloy plates with different input conditions. The statistical model helps us to develop the relation between different geometrical parameters of the Tibia implant plate. As determined by the present work, the parameter most influencing is implant plate length. This outcome will be used to select the implant for a specific patient, resulting in a reduction in implant failure post-surgery.

Accelerating Lithium Deposition Kinetics Via Lithiophilic Ag‐Decorated Graphitic Carbon Nitride Spheres for Stable Lithium Metal Anode

This study presents a novel Li metal host material with a unique hollow nano‐spherical structure that incorporates Ag nano‐seeds into a graphitic carbon nitride (g‐C3N4) shell layer, referred to as g‐C3N4@Ag hollow spheres. The g‐C3N4@Ag spheres provide a managed internal site for Li metal encapsulation and promote stable Li plating. The g‐C3N4 spheres are uniformly coated using polydopamine, which has an adhesive nature, to enhance lithium plating/stripping stability. The strategic presence of Ag nano‐seeds eliminates the nucleation barrier, properly directing Li growth within the hollow spheres. This design facilitates highly reversible and consistent lithium deposition, offering a promising direction for the production of high‐performance lithium metal anodes. These well‐designed g‐C3N4@Ag hollow spheres ensure stable Li plating/stripping kinetics over more than 500 cycles with a high coulombic efficiency of over 97%. Furthermore, a full cell made using LiNi0.90Co0.07Mn0.03O2 and Li‐g‐C3N4@Ag host electrodes demonstrated highly competitive performance over 200 cycles, providing a guide for the implementation of this technology in advanced lithium metal batteries.

Pantarsal arthrodesis stabilized with circular external skeletal fixators in 8 dogs (2010-2022).

To report the surgical technique, complications, and outcomes of 8 dogs that underwent a unilateral pantarsal arthrodesis stabilized using a circular external skeletal fixator (CESF) construct for the treatment of uni- or multilevel tarsal instability. 8 dogs. Medical records from 2010 to 2023 from 2 small animal hospitals were retrospectively reviewed for dogs undergoing pantarsal arthrodeses stabilized with CESF. Data collected for each dog included signalment, injury etiology, construct configuration, radiographic imaging, antimicrobial use, complications, length of time until construct removal, and outcome based on clinical evaluation by the owner and veterinary surgeon. 8 dogs met the requirements of inclusion for the study. Dogs had a mean age of 5.5 years (range, 0.42 to 13 years) and weight of 15.1 kg (range, 2.5 to 26.4 kg). Angulated 3- and 4-ring constructs were used in 5 and 3 dogs, respectively, with or without hybridization. Tarsi were stabilized with a mean angle of extension of 124.8° (range, 111.5° to 136.5°). Fixator removal was performed at a mean time of 11.3 weeks (range, 6 to 16 weeks). Complications developed in 4 dogs, 2 of which had poor clinical outcomes despite additional interventions, including recurrent digit trauma and poor limb use postoperatively. Six dogs had excellent outcomes. A CESF may be considered as an alternative to plate stabilization when performing a pantarsal arthrodesis. This fixation requires rigorous postoperative care but obviates the need for supplemental postoperative coaptation.

CONSTRUCTION OF THE RAILWAY TRACK OF UKRAINE AND PROSPECTS FOR THEIR IMPROVEMENT

The goal. The process of improving the design of the railway track requires a detailed study of the history of the development of its structural elements, methods of combination, interconnections and limits of mutual influence. Modern track designs are the result of many years of hard work by scientists and long operational tests. Some designs were inventions at the time, some were breakthrough technologies, some remained just ideas, and some have existed for more than a century. The study of the history of the development of railway track structures and modern existing structures in operation made it possible to identify a promising direction for improvement and further development, taking into account the existing problems on the mainline transport tracks and industrial enterprise tracks. Reinforced concrete sleepers and intermediate fasteners that allow for track gauge adjustment are the railroad track structure that should be improved in the coming years. Improving railroad track design is a continuous process in the development of rail transport. Recently, new track designs have been introduced on Ukrainian railways. As a rule, the problems of track facilities are first considered and technical tasks are formulated. Then, a public discussion is held in the scientific and practical environment and an appropriate development strategy is born. Such a strategy is reviewed and approved at scientific and technical meetings and specialized commissions. This article aims to identify promising areas for improving the track design and solving the problems of installing and operating a continuous track by analyzing existing designs and world experience of railways. Methods. Methods of scientific analysis and synthesis of track development design, methods of analytical geometry. Results. Based on the analysis of the history of the development of the railroad track structure and modern designs, a promising direction of improvement is proposed. A promising railroad track structure is defined as a reinforced concrete sleeper and fasteners capable of forming an adjustable track gauge of up to 1545 mm. At the same time, it is necessary that the new design has sufficient stability of the jointless track plates. Practical significance. The application of the proposed structure within small radius curves, provided that the results of trial operation and testing of the established procedure are positive, will reduce the operating costs associated with the current maintenance of the tracks, expand the scope of laying of the jointless track and use reinforced concrete sleepers in small radius curves at industrial enterprises.

The Design and Validation of a High-Precision Angular Vibration Calibration System Based on a Laser Vibrometer.

This paper presents the design and validation of a high-precision angular vibration calibration system based on a laser vibrometer, aimed at meeting the high-precision requirements for measuring small angular vibrations. The system primarily consists of a self-driving angular vibration platform and a laser vibrometer. The platform is isolated from ground interference via an air-floating platform and uses a split-type motor to control the platform, generating specific angular vibrations. Detailed simulations of the platform's modal characteristics and the stability of the spring plates were conducted using the finite element analysis software ANSYS 11. Moreover, fundamental frequency testing and measurement accuracy testing were conducted on the system. Experimental results demonstrate that the system has a fundamental frequency of 2.69 Hz and a maximum measurement error of 0.00172″, confirming the system's effectiveness in dynamic characteristics, stability, and measurement accuracy. This research provides essential technical support for high-precision angular vibration control in spacecraft.