Apparent Deformation Research Articles

Indications and limitations of conservative and invasive treatment of the inflammatory shoulder joint and the shoulder girdle

An inflammatory rheumatic shoulder can be assessed as aforgotten joint. Apparent problems and deformities of the hands and feet are prioritized in the perception of rheumatic patients. In contrast, however, involvement of the shoulder joint in the context of an inflammatory rheumatic disease is very high with up to 85% [2]. Loss of shoulder function and pain can be well compensated for along time. This means that further diagnostics are only carried out when the joint is already destroyed and joint-preserving treatment options are obsolete. The various tools of evidence-based conservative treatment can be used to relieve pain and improve function. The cause of joint destruction, inflammatory synovitis, must be treated with medication or, if there is no response to basic immunomodulatory treatment, invasively. In order to contain further destruction of the joint, injections of glucocorticoids and radiosynoviorthesis are initially carried out. This should be followed by arthroscopic synovectomy of the shoulder joint due to better results, especially in early stages of destruction (LDE 0-3).

Characterizing Surface Deformation of the Earthquake-Induced Daguangbao Landslide by Combining Satellite- and Ground-Based InSAR.

The Daguangbao landslide (DGBL), triggered by the 2008 Wenchuan earthquake, is a rare instance of super-giant landslides globally. The post-earthquake evolution of the DGBL has garnered significant attention in recent years; however, its deformation patterns remain poorly characterized owing to the complex local topography. In this study, we present the first observations of the surface dynamics of DGBL by integrating satellite- and ground-based InSAR data complemented by kinematic interpretation using a LiDAR-derived Digital Surface Model (DSM). The results indicate that the maximum line-of-sight (LOS) displacement velocity obtained from satellite InSAR is approximately 80.9 mm/year between 1 January 2021, and 30 December 2023, with downslope displacement velocities ranging from -60.5 mm/year to 69.5 mm/year. Ground-based SAR (GB-SAR) enhances satellite observations by detecting localized apparent deformation at the rear edge of the landslide, with LOS displacement velocities reaching up to 1.5 mm/h. Our analysis suggests that steep and rugged terrain, combined with fragile and densely jointed lithology, are the primary factors contributing to the ongoing deformation of the landslide. The findings of this study demonstrate the effectiveness of combining satellite- and ground-based InSAR systems, highlighting their complementary role in interpreting complex landslide deformations.

Three Years Follow-Up of Single-Stage Correction with Modified Chula Technique for Frontoethmoidal Encephalomeningocele: The Advantage of The Teamwork Approach (A Case Report)

Backgrounds: The main objective of Frontoethmoidal encephalomeningocele (FE) treatment are neural morbidities defect correction and aesthetically pleasing looks. Staged procedures are used to be performed in Indonesia. This article aimed to reveal the result of FE correction through the single-stage modified Chula technique (ST-MCT) procedure in collaboration with the neurosurgery team. Case Reports: A rare case of 5 years old girl diagnosed with FE was reported in this study. The FE was slowly increased in size, causing apparent facial deformity and the appearance of telecanthus. An ST-MCT procedure in collaboration with the neurosurgery team was conducted to correct the defects. The IOD values, IPD values, postoperative complications, and anesthetic improvements were evaluated in this study. Result: The patient was well after the surgery, with no complications and short length of stay. There were noted improvement of ICD, IOD and IPD postoperative follow up. At three years after the surgery ICD= 29mm; IOD= 26mm; IPD= 52 mm (normal range). Summary: ST-MCT procedure conducted in collaboration with neurosurgery team had shown excellent correction of ICD, IOD, and IPD values, no complication, shorter length of stay, and minimal scars. It considers as the most proper technique to reach a good result of correction and aesthetically pleasing looks in FE cases.

The Evolution of Nanoscale Third Body Layer Revealed by Graphite Structural Superlubric Contact.

Revealing the evolution of nanoscale third bodies confined between sliding surfaces is essential to understanding the friction and electrical properties for solid contacts. Here, with graphite/graphite contacts in structural superlubricity, a state of no wear and ultralow friction, we in situ reveal the morphological evolution of a third body layer introduced by air through measuring friction and conductance during cyclic hold-slide tests. The directional transport of confined molecules causes apparent elastic deformation of the third body layer, leading to local graphite/graphite direct contact. Together with a proposed quantum tunneling effective thickness (deff) model, a constant volume of third bodies with a sub-nm thickness is observed. Our work provides a feasible approach to investigate the kinetics of substances under nanoscale confinement.

Study on roadway roof deformation and coal pillar energy accumulation instability

To address coal pillar instability, the study focuses on the 3−1 coal seam coal pillar at Nanliang Coal Mine. It analyzes the bending deformation energy of the main roof and the pre-yield elastic energy of the coal pillar’s elastic zone through theoretical analysis, similar simulation, and field measurements. The formula for the bending elastic energy of the main roof is derived by establishing the mechanical model of the roadway’s main roof near the goaf side. Based on the side abutment stress distribution of the coal pillar, the calculation of the pre-yield elastic energy distribution along the width direction of the coal pillar’s elastic zone is conducted, leading to the derivation of the instability energy criterion for the coal pillar. The range analysis method is used to analyze the influencing factors and distribution patterns of the bending elastic energy of the main roof and the pre-yield elastic energy of the coal pillar’s elastic zone. Findings indicate that the main roof’s tensile strength is the primary factor influencing bending elastic energy. Higher tensile strength of the main roof, and smaller load, larger thickness and elastic modulus on the overlying strata, lead to higher bending elastic energy in the main roof. The internal friction angle, width of the coal pillar, and elastic modulus of the coal seam notably impact the pre-yield elastic energy of the coal pillar’s elastic zone. A larger internal friction angle and coal pillar width, along with a smaller elastic modulus, result in higher pre-yield elastic energy in the coal pillar’s elastic zone. Using the working face of 3−1 coal seam in Nanliang Coal Mine as the engineering context, the study calculates the minimum coal pillar width required for stability. Physical simulations and field monitoring demonstrate that with a 9 m—wide coal pillar, there is no apparent deformation or failure in the surrounding rock of the roadway, indicating good internal rock stability.

Hot deformation behavior of an ignition resistance Mg–6Zn-0.6Zr-1.2Ca magnesium alloy

The addition of Ca could enhance the ignition point of magnesium alloys but impairing their workability, so it is essential to study the hot deformation behavior of new Ca-containing ignition resistance magnesium alloys. The hot deformation behavior of a new ignition resistance Mg–6Zn-0.6Zr-1.2Ca alloy was investigated by compression experiment in the temperature range of 240 °C–360 °C, strain rates of 10−3 s−1-1 s−1 and height reduction of 10%–60%. The true stress-strain curves show that flow stress decreases as the deformation temperature increases or the strain rate decreases. Microstructure analysis shows that higher temperatures and lower strain rates are favorable for DRX, while higher strain rates promote the fragmentation of the Ca2Mg6Zn3 phase. Meanwhile, the existence of Ca2Mg6Zn3 phase make the DRX process be dominated by the particle-induced subgrain nucleation mechanism. By superposition of the power dissipation map and the instability map, a hot processing map of true strain of 0.6 is generated. According to analyses on the processing map and microstructure evolution, the instability of processing map can be attributed to the greater dislocation motion resistances, insufficient DRX, and Ca2Mg6Zn3 phase with low-melting point. Conversely, the optimal processing parameters for the alloy were determined as 280–360 °C/0.001–0.01 s−1 in safe zone with a high η above 0.3, which can be due to the apparent DRX and good deformation coordination.

Distal Tibial Dome Osteotomy With Ilizarov Fixation in Correction of Ankle Deformity Resulting From Malunited Ankle Fusion

Background: Distal tibial osteotomy is used in the treatment of ankle deformities. Many methods of fixation of this osteotomy were described, including plates, pins, and ilizarov. Dome osteotomy is a cylindrical osteotomy with no bone loss, with the axis of bone is rotated around the center of the circle. We conducted a case series of treatment of ankle deformity due to malunited ankle fusion with distal tibial dome osteotomy. Methods: Eight patients with a history of poliomyelitis with ankle deformity due to a malunited ankle fusion underwent distal tibial dome osteotomy with ilizarov fixation for deformity correction. Postoperative follow up was done up to 12 months postoperatively. We intended to follow up the union of the osteotomy, the axis of the limb, the external clinical appearance, and patient satisfaction. Results: Deformity correction was achieved in all patients regarding the clinical alignment, with no apparent clinical residual deformity in coronal, sagittal plane, or rotational deformity, the limb was cosmetically straight with a plantigrade foot satisfactory to the patients with improving quality of gait. The osteotomy fully united in all patients in a period of 8 to 11 weeks with an average of 9.3 weeks, after which frame was removed. No patient had nonunion or delayed union of the osteotomy. Three patients had pin tract infection during the period of the fixator which was treated by local dressings and antibiotics. Conclusion: Distal tibial focal dome osteotomy fixed by ilizarov is an effective treatment option in malunited ankle fusion deformities.

Biomechanical Evaluation of a Locally Manufactured Modular External Fixator for Tibial Shaft Fractures

Background: Modular external fixations used in the Philippines are manufactured abroad, leading to high costs and limited availability, making them unaffordable for most Filipino patients. The reliability of some external fixators is limited because not all have undergone biomechanical testing. Objective: This study aims to determine the biomechanical stability of locally manufactured modular external fixator clamps (iFIX) versus commercially available fixators (Roger-Anderson) for tibial shaft fractures. Methodology: The biomechanical stability (stiffness, yield, ultimate strength) under loading of the local prototypes compared with the commercially available fixators. Result: No slippage was observed in all rods, pins, and clamps in all groups. No bending occurred in any rods or pins in all groups. There was also no apparent deformation of the internal threading of the pins within the tibial analogs. The commercial fixator group’s ultimate load to failure up was double (110.57% difference) that of the local prototype. Conclusion: The differences in the biomechanical performance between the iFIX and Roger-Anderson clamps may be attributed to variations in clamp material composition. The iFIX fixator exhibited lower stiffness but did not display deformation under axial loading, component displaced slippage, or thread loosening, making it comparable to the commercial fixator.

ANTISAPROLEGNIA ACTIVITY OF METHANOLIC EXTRACT OF ZINGIBER OFFICINALE IN BUNNEI (BARBUS SHARPEYI) HATCHERY

Usage of chemicals such as malachite green to disinfect fish eggs in aquaculture has been banned in many countries around the world due to its environmental negative impact. This study aimed to evaluate the Zingiber officinale rhizomes extract as an antifungal agent during incubation period of Bunnei eggs and comparison of its effects with malachite green. For this purpose 24 hours after fertilization, methanolic extract of Zingiber officinale rhizomes in four groups with a concentration of 500, 750, 1000, and 1250 mg/L and three replications per concentration in a (10 minute) bath every 12 hours and malachite green group with a concentration of 0.1 mg/L for (6 minutes) bath was used twice a day and control group without antifungal agents under the same physiochemical conditions as other treatments were tested. The present study showed that the highest percentage of fungal infection was 41.82±0.5 % for the control group and the lowest 0.3±0.5 % was obtained for the treatment of 1250 mg/L of Zingiber officinale rhizomes. Also, the results showed that there were significant differences between treatments of different concentrates of Zingiber officinale rhizomes and with malachite green group in fungal infection, percentage of fertilization and survival do not exist (P>0.05.) No apparent deformity and abnormality were observed in the hatched larvae of Bunnei, so the extract of Zingiber officinale rhizomes with concentration 500 mg /L can be used to disinfect Bunnei eggs during Incubation period and safe material for humans and the environment.

Tunable afterglow for mechanical self-monitoring 3D printing structures

Self-monitoring materials have promising applications in structural health monitoring. However, developing organic afterglow materials for self-monitoring is a highly intriguing yet challenging task. Herein, we design two organic molecules with a twisted donor-acceptor-acceptor’ configuration and achieve dual-emissive afterglow with tunable lifetimes (86.1–287.7 ms) by doping into various matrices. Based on a photosensitive resin, a series of complex structures are prepared using 3D printing technology. They exhibit tunable afterglow lifetime and Young’s Modulus by manipulating the photocuring time and humidity level. With sufficient photocuring or in dry conditions, a long-lived bright green afterglow without apparent deformation under external loading is realized. We demonstrate that the mechanical properties of complex 3D printing structures can be well monitored by controlling the photocuring time and humidity, and quantitively manifested by afterglow lifetimes. This work casts opportunities for constructing flexible 3D printing devices that can achieve sensing and real-time mechanical detection.

Wettability and adhesion of nanotubes applied to the surface of titanium implants by anodic oxidation.

The aim of this study was to evaluate the wettability and adhesion of self-organized TiO2 nanotubes formed on the surface of 8 commercially pure titanium (CP-Ti) disks and 12 dental implants (n = 12) by anodization in a glycerol-H2O (50-50 v/v) electrolyte containing NH4F. Two disk specimens were not submitted to anodization (controls). The nanotubes thus obtained had average dimensions of 50 nm in diameter by 900 nm in length. The treated disk specimens were stored for 2, 14 and 35 days (n = 2), and the wettability of their surfaces was evaluated with a goniometer at the end of each storing period. The adhesion of nanotubes to titanium was evaluated by field emission scanning electron microscopy after subjecting the 12 implants to a simulation of clinical stress in two-part synthetic bone blocks. After installing the implants with the application of an insertion torque, the two halves of the block were separated, and the implants were removed. The nanotubes remained adhered to the substrate, with no apparent deformation. The contact angles after 14 days and 35 days were 16.47° and 17.97°, respectively, values significantly higher than that observed at 2 days, which was 9.24° (p < 0.05). It was concluded that the method of anodic oxidation tested promoted the formation of a surface suitable for clinical use, containing nanotubes with levels of wettability and adhesion to titanium compatible with those obtained by other methods found in the literature. The wettability, however, did not prove stable over the tested storage periods.

Effect of burnt tire-ash (water-soluble fraction) on blood and histopathological markers in Clarias gariepinus

Aquatic habitats serve as pollutant reservoirs and experience massive pollution disasters due to anthropogenic pressure. The effect of the Water-Soluble Fraction (WSF) of burnt tire ash (BTA) was investigated on Clarias gariepinus juvenile using blood biomarkers as well as liver and gill histology. The model fish were exposed to 5 % (0.56 g/L), 10 % (1.12 g/L) and 20 % (2.24 g/L) of 96-hr LC50 (11.2 g/L) value of BTA sub-chronic doses during the experiment. Hematological indices, the liver, and gill histology were studied throughout the 28-day exposure study, which was followed by a 14-day post-exposure trial. The studies revealed that BTA-exposed fish had reduced red blood cells, packed cell volume, and hemoglobin levels with time, whereas white blood cells and leukocyte numbers increased. Concentration-dependent histopathologic abnormalities such as hyperplasia, telangiectasis, hemorrhage, desquamation, lamellar edema, and vacuolation were observed in the gill of the affected fish, in contrast to the control. Likewise, the presence of histopathologic abnormalities in the liver of BTA-exposed fish, such as vacuolar degeneration, hyperplasia, dilated portal vein, pyknotic nucleus formations, hypertrophy hepatocytes, and aggregated macrophages, was concentration-dependent. Following apparent histologic deformities that persisted in the tissues after recovery, healing from BTA exposure was only partial. C. gariepinus is an essential bioindicator of burnt tire ash’s ecotoxicological impact. Point and non-point traces of burnt-tire ash to the aquatic systems may harm aquatic animal species, thus necessitating preventative actions.

Revealing the microstructure evolution, deformation behavior and tensile properties of AZ31/AM60 dissimilar Mg alloy joints under different welding technologies

In this work, friction stir welding (FSW) and tungsten inert gas welding (TIG) were applied to prepare two kinds of dissimilar AZ31/AM60 Mg joints. The relationship between mechanical properties, deformation behavior, and microstructure characteristics of both joints was investigated. Microstructural characterization demonstrated that a significant grain orientation fluctuation occurred in the weld zone (WZ) of the FSW joint, but this was not obvious for the TIG joint. Compared with the base metals, the grain size of the FSW joint slightly decreased, but the grain of the TIG joint obviously coarsened. Locally strong texture appeared in the WZ of the FSW joint with a symmetrical distribution, while a random texture character occurred in the TIG joint. Furthermore, the WZ of the TIG joint possessed more and larger second phases than the FSW joint. Tensile tests indicated that both joints had equivalent yield strength (∼120 MPa) and ultimate tensile strength (∼255 MPa), but the elongation (9.0 %) of the FSW joint was lower than that of the TIG joint (12.1%). The similar strength originated from the higher Schmid factors (SFs) of basal slip and extension twinning in the WZ side of the FSW joint and the larger grain size and lower dislocation degree in the heat-affected zone of the TIG joint. The decreased elongation in the FSW joint was due to the apparent inhomogeneous deformation caused by significant SFs (basal slip) fluctuation, while the weaker SFs fluctuation and notable twinning behavior in the TIG joint contributed to the relatively higher elongation.

Deep-Blue Narrowband Hetero[6]helicenes Showing Circularly Polarized Thermally Activated Delayed Fluorescence Toward High-Performance OLEDs.

Helicenes exhibit substantial potential as circularly polarized luminescence (CPL) active molecules. However, their application in circularly polarized organic light-emitting diodes (CP-OLEDs) is typically hindered by the challenge of integrating both high color purity and efficient triplet-harvesting capability, particularly in the blue spectral region. Herein, a series of hetero[6]helicene-based emitters that is strategically engineered through the helical extension of a deep-blue double-boron-based multiple resonance thermally activated delayed fluorescence (MR-TADF) motif, is introduced. Importantly, the helical extension does not cause apparent structural deformation or perturb frontier molecular orbitals; thus, preserving the deep-blue emission and MR-TADF characteristics of the parent molecule. This approach also leads to reduced reorganization energy, resulting in emitters with narrower linewidth and higher photoluminescence quantum yield. Further, the helical motif enhances the racemization barrier and leads to improved CPL performance with luminescence dissymmetry factor values up to 1.5 × 10-3 . Exploiting these merits, devices incorporating the chiral dopants demonstrate deep-blue emission within the Broadcast Service Television 2020 color-gamut range, record external quantum efficiencies (EQEs) up to 29.3%, and have distinctive circularly polarized electroluminescence (CPEL) signals. Overall, the authors' findings underscore the helical extension as a promising strategy for designing narrowband chiroptical materials and advancing high-definition displays.

Magneto‐Mechano‐Electric Cascade Stimulation System Accelerates Wound Healing Constructed by Biodegradable Magnetoelectric Nanofibers

AbstractReconstructing the intricate biophysical microenvironment to provide multiple biologically beneficial stimulation is deemed a promising therapeutic strategy. However, developing multi‐biophysical stimuli with wireless integration and accurate management remains a formidable challenge. Herein, a novel design of a magneto‐mechano‐electric (MME) cascade stimulation system based on aligned magnetoelectric nanofibrous membranes (PLLA/CFO) is reported. Simply regulating the loading amount of CFO nanoparticles endows the PLLA/CFO membranes with excellent magnetism, enhanced crystallization, and resultant piezoelectric responsiveness, thus providing built‐in topographical guidance and nanoscale magnetic field as well as manageably remote stimulation. Specifically, assisted by an external magnetic field (EMF), the magnetic response in PLLA/CFO can be amplified to offer an apparent deformation, which then induces the output of mechanical and electrical cues. Benefiting from the slow degradability of PLLA and continuous EMF triggering, such a performance can be well modulated to match the practical wound healing process, demonstrated by the repair of a rat full‐thickness skin defect. More importantly, this work offers a new strategy to reconstruct the complex biophysical microenvironment in a wireless remote manner.

Virtual 3D femur model to assess femoral version: comparison to the 2D axial slice approach.

Quantifying femoral version is crucial in diagnosing femoral version abnormalities and for accurate pre-surgical planning. There are numerous methods for measuring femoral version, however, reliability studies for most of these methods excluded children with hip deformities. To propose a method of measuring femoral version based on a virtual 3D femur model, and systematically compare its reliability to the widely used Murphy's 2D axial slice technique. We searched our imaging database to identify hip/femur CTs performed on children (<18 years old) with a clinical indication of femoral version measurement (September 2021-August 2022). Exclusion criteria were prior hip surgery, and inadequate image quality or field-of-view. Two blinded radiologists independently measured femoral version using the virtual 3D femur model and Murphy's 2D axial slice method. To assess intrareader variability, we randomly selected 20% of the study sample for re-measurements by the two radiologists >2 weeks later. We analyzed the reliability and correlation of these techniques via intraclass correlation coefficient (ICC), Bland-Altman analysis, and deformity subgroup analysis. Our study sample consisted of 142 femurs from 71 patients (10.6±4.4 years, male=31). Intra- and inter-reader correlations for both techniques were excellent (ICC≥0.91). However, Bland-Altman analysis revealed that the standard deviation (SD) of the absolute difference between the two radiologists for the Murphy method (mean 13.7°) was larger than that of the 3D femur model technique (mean 4.8°), indicating higher reader variability. In femurs with hip flexion deformity, the SD of the absolute difference for the Murphy technique was 17°, compared to 6.5° for the 3D femur model technique. In femurs with apparent coxa valga deformity, the SD of the absolute difference for the Murphy technique was 10.4°, compared to 5.2° for the 3D femur model technique. The 3D femur model technique is more reliable than the Murphy's 2D axial slice technique in measuring femoral version, especially in children with hip flexion and apparent coxa valga deformities.

Variation of Poisson’s Ratio of NiTi During Pseudoelastic Deformation

NiTi alloy exhibits a stress-induced B2 ↔ B19' martensitic transformation. This transformation is practically isochoric, thus has a Poisson’s ratio of 0.5. This imposes a complex interaction with elastic deformation which has a lower Poisson’s ratio and with plastic deformation which is not recoverable when interacting with other materials in a composite or an assembly, thus a challenge for the design of such materials or devices using them. This study investigated the variation of the Poisson’s ratio of a NiTi alloy during pseudoelastic deformation by means of the digital image correlation technique. The Poisson’s ratio of the alloy was found to increase from 0.39 in the apparent elastic deformation stage to 0.44 prior to the onset of the Lüders-type deformation and then to 0.48 after the passing of the Lüders band.

Температурна характеристика електричного опору тензометра при вимірюванні статичних та термічних напружень деталей при температурі до 700 °С

An overview of the existing methods of measuring static stresses at elevated temperatures, at which it is problematic to use classical strain gauges, and methods of compensating the imaginary temperature deformation was performed. Namely: the use of multi-component alloys, the manufacture of active and compensatory sensitive elements from different alloys, which should theoretically compensate for each other's shortcomings. In practice, this can be sufficiently achieved only in a narrow temperature range. The described primary transducer is a rectangular strain-gauge rosette for measuring static and thermal stresses in structural parts operating under extreme conditions at temperatures up to 700°C. This sensor is a two-layer rosette consisting of two sensitive elements (SE), the main axes of which are rotated relative to each other by 90°. The lower SE perceives the main deformation of the part, and the upper one, located above the lower one, plays the role of a temperature-compensating electrical resistance of the element and simultaneously registers the transverse deformation of the part. SE rosettes were made of a wire with a diameter of 30 microns of the Х20Н80 alloy and fixed to each other and to the part using Ц-165-32А cement. The experimental study consisted in determining the temperature characteristics of the resistance of both the lower and the upper SE of the studied strain gauge associated with the temperature expansion of the part-strain gauge system as well as with the shunting of the insulator-connector and the change in the specific resistance of the SE material. Experimental determination of apparent strain gauge deformation at different temperatures was performed. To determine the influence of the coefficient of linear expansion of the material of the part on the change in the resistance of the SE, strain gauges were attached to samples of various materials. The change in the apparent deformation of the strain gauge in the temperature range from room temperature to 700 °C is shown. Its maximum value for the ceramic sample was less than 350 µm/m, for the 30ХГСА steel sample it was less than 1000 µm/m, and for the ВЖЛ14Н-ВІ alloy sample it was less than 750 µm/m. Dependencies were obtained that allow corrections to be made in the result of a real study of the stressed state of the part to achieve the maximum accuracy of measurements.

FEA and experimental ultimate burst pressure analysis of type IV composite pressure vessels manufactured by robot-assisted radial braiding technique

Composite pressure vessels (CPVs) are lightweight and high-strength containers that can be used for the storage of compressed gases, including hydrogen. While hydrogen is a promising alternative energy source, storage of hydrogen comes with its significant challenges which requires a need for the efficient production of CPVs. Most commonly, CPVs are manufactured using filament winding technology. Due to the rise in the need for pressure vessels, there is a need for alternative high-throughput manufacturing techniques. Braided, in comparison to filament winding, has a high throughput and is less research manufacturing technology for CPVs. In this study, the applicability of braiding for the manufacturing of CPV is researched. Two types of 2D braids, namely the conventional and unidirectional, braiding were studied for their application in such structures, 24K and UD tanks, respectively. Dry carbon fiber (T700S – 24K) and HDPE liner were used to manufacture two different types of composite pressure vessels (CPVs), by robot-assisted radial braiding technique. After the preform of the braiding process was finished, CPVs were cured with a vacuum infusion process (VIP) by using a mold system. Produced braided CPVs were subjected to a hydrostatic burst test in order to determine their ultimate burst pressure point. Finite element analysis (FEA) was used to optimize and correlate experimental burst pressure test results. Ansys ACP was utilized to design composite structures by dividing both tanks’ domes into sub-sections. Results suggest that the experimental burst pressure test of 24K and UD tanks were identified as 200 bar and 150 bar, respectively. UD vessel ruptured close to the dome, whereas the 24K fracture point was located in the center of the dome. UD braided CPV was shown to have a smaller apparent burst deformation (rupture) scale than 24K CPV. In comparison to 24K, the UD braided CPV is 5.7% lighter and requires 20.9% less carbon fiber in production. FEA results were consistent with experimental results in terms of the burst pressure point. For both 24K and UD, the fiber failure starts at the point where the cylinder section and boss system are connected under pressure, and fiber failures continue to progress steadily as the pressure increases.

Design and analysis of longitudinal–flexural hybrid transducer for ultrasonic peen forming

Ultrasonic peen forming (UPF) is an emerging technology that exhibits great superiority in both its flexible operating modes and the deep residual stress that it produces compared with conventional plastic forming methods. Although ultrasonic transducers with longitudinal vibration have been widely studied, they have seldom been incorporated into UPF devices for machining in confined spaces. To meet the requirements of this type of machining, a sandwich-type piezoelectric transducer with coupled longitudinal–flexural vibrational modes is proposed. The basic structure of the transducer is designed to obtain large vibrational amplitudes in both modes. Experimental results obtained with a prototype device demonstrate the feasibility of the proposed transducer. The measured vibrational amplitude for the working face in the longitudinal vibrational mode is 1.0 μm, and electrical matching increases this amplitude by 40%. The flexural vibration characteristics of the same prototype transducer are also tested and are found to be slightly smaller than those of longitudinal mode. The resultant working strokes of the UPF impact pins reach 1.7 mm and 1.2 mm in the longitudinal and flexural modes, respectively. The forming capability of the prototype has been evaluated via 15-min machining on standard 2024-T351 aluminum plates. After UPF, an improved surface morphology with lower surface roughness is obtained. The aluminum plate test piece has an apparent upper deformation with an arc height of 0.64 mm. The measured peak value of the compressive residual stress is around 250 MPa, appearing at a depth of 100 μm. The proposed longitudinal–flexural hybrid transducer thus provides a high-performance tool for plate peen forming in confined spaces.