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Conventional beam elements ignoring distortion may overestimate the lateral resistance of frames and curved beams made of monosymmetric I-sections. This paper introduces two new distortional modes represented by mechanical couples relative to twisting and shearing of the two flanges that are opposite in directions but unequal in magnitudes. A straight beam element with nine degrees of freedom (DOFs) per node, including the conventional three translations, three rotations, warping and the new two distortions, is newly derived. This allows all the DOFs of the connected elements at a common joint to be easily transformed to the global coordinates for stiffness assembly. As a result, the warping–distortion compatibility problem that occurs in frames and curved beams is resolved. In the numerical examples, the results produced by the present beam element is demonstrated to agree excellently with the shell-element solutions for the lateral-distortional deformation of the angled frame and curved beam. It is observed that the cross-sectional distortion effect becomes extremely significant for angled frames of short unbraced length and for curved beams of high curvature. [ABSTRACT FROM AUTHOR]

The detection of bolt loosening in key components of aircraft engines faces problems such as complex and difficult-to-establish bolt loosening mechanism models, difficulty in identifying early loosening, and difficulty in extracting signal features with nonlinear and non-stationary characteristics. Therefore, the automated structural bolt micro looseness monitoring method using deep learning was proposed. Specifically, the addition of batch normalization methods enables the established Batch Normalized Stacked Autoencoders (BNSAEs) model to converge quickly and effectively, making the model easy to build and effective. Additionally, using characterization functions preprocess the original response signal not only simplifies the data structure but also ensures the integrity of features, which is beneficial for network training and reduces time costs. Finally, the effectiveness of the proposed method was verified by taking the bolted connection structures of two key components of aircraft engines, namely bolt connection structures and flange connection structures, as examples. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Methods Results Conclusion To report the 10‐year clinical and radiographic outcomes of implants placed in grafted (GBR) and non‐grafted (no‐GBR) sites in a Swiss specialist private practice using hydrophilic implants with a low surface roughness flange.Fifty consecutively enrolled patients received 159 hydrophilic implants with a low surface roughness flange. A first re‐evaluation was performed 1 year after delivery of restoration (T1). An additional examination was performed at the 10‐year follow‐up (T2) including the assessment of clinical (i.e., periodontal/peri‐implant pockets probing depths (PPD) (mm), full‐mouth bleeding score (%), implant survival rate, mid‐buccal keratinized mucosa (KM) width in mm, and peri‐implant phenotype), and radiographic (i.e., marginal bone level change [ΔMBL]) outcomes. Biological, mechanical and technical complications were also recorded.Out of the initial cohort, 22 patients (9/40.9% male and 13/59% female) and 63 implants (47 with GBR, 16 without GBR), could be re‐examined at T2. Overall, ΔMBL (T2‐T1) was −0.56 ± 0.96 mm. In the GBR group, ΔMBL were significantly higher at the distal sites compared to the no‐GBR group (−0.75 ± 1.17 mm vs. −0.12 ± 1.29 mm, p = 0.045), however, in the GBR group MBL started at a higher level at T1 but were similar with the no‐GBR group at T2. Implant survival was 100% with only very few technical complications (6.3%). Mean PPD amounted to 3.84 ± 1.00 mm with significantly higher values in the GBR group (3.98 ± 1.08 mm vs. 3.45 ± 0.60 mm; p = 0.016). Nineteen implants (30.1%) were diagnosed with peri‐implant health while 44 (69.9%) presented with peri‐implant mucositis.Within the limitations of this study, favorable clinical and radiographic conditions were recorded around hydrophilic implants with a low surface roughness flange placed in pristine and augmented bone after 10 years in function. [ABSTRACT FROM AUTHOR]

AbstractTo study the influence of opening ratio on the shear performance of steel-bamboo composite cellular beams (SBCC), taking the opening size as the basic parameter, experimental research was carried out on five test beams. The failure modes and deformation characteristics of the specimens were observed, and the influence and law of the change of hole size on the shear performance of steel-bamboo composite cellular beams were analyzed. Through nonlinear finite element simulation calculation, multi-parameter analysis was carried out on the composite cellular beams, and the contribution of flanges to the shear performance of cellular composite beams was studied. The results show that the integrity of steel-bamboo composite cellular beams is good. The failure is mainly manifested as the fracture of bamboo web at the beam hole area, the buckling of section steel and the debonding and separation of steel-bamboo interface. The opening ratio has a great influence on the shear performance of steel-bamboo composite cellular beams. The thickness of bamboo flange cannot be ignored for the shear contribution of cellular beams. The shear capacity of cellular beams is shared by flanges and webs. The larger the opening ratio, the greater the shear contribution of flanges to composite cellular beams. [ABSTRACT FROM AUTHOR]

ABSTRACT With shortening development cycles, digital development rises in importance. Therefore, we present an approach to segment digital carlines based on their corrosion risk using digital data sets. A typical carline is described via STL‐Files that accumulate to approximately 25 million triangles. While physics‐based simulation models exist capable of predicting the onset of corrosion in local geometry settings, an application to a complex surface mesh would be prohibitively expensive to compute. This calls for data reduction techniques that reduce the number of triangles by identifying areas prone to corrosion, as well as those that are protected by measures such as adhesives. Therefore, the implementation of corrosion‐prone areas of a body‐in‐white part, as presented in Waibel et al., is extended by implementing a design measure segmentation for adhesive pipes. This work introduces a method to predict corrosion‐protected areas for flanges with adhesives by implementing a feature extraction and a transfer learning‐based workflow for data‐efficient training. The results of the implementation are the validated prediction on body‐in‐white parts with high precision. [ABSTRACT FROM AUTHOR]

The flange holes on large aluminum ball shells are processed on-site by industrial robots, and the flange holes need to ensure the hole position and axial accuracy requirements at the same time, but it is challenging to ensure that these two indexes meet the requirements at the same time due to the lower machining accuracy of the industrial robots. For this reason, the paper proposes a robot integrated error compensation method for hole position and axial deviation constraints. First, the robot machining path is generated, and the cutting allowance and hole inner wall measurement strategy are determined by running the machining path empty before machining. Integrated error compensation is then introduced and a new hole surface is constructed as a mirror surface under its conditions. The tool path is adjusted according to the mirror compensation principle to ensure consistency between the machined and target holes. The reconstructed target hole surface satisfies the integrated error constraints and realizes the balanced constraints of positional and axial tolerances, making full use of both tolerances. Finally, the method's effectiveness has been verified in a large-scale work. Experimental results show that hole position error is reduced from uncompensated (1.03, − 0.51) mm to compensated (0.25, − 0.005) mm, and axial error from uncompensated 22.32 mm to compensated 1.39 mm. [ABSTRACT FROM AUTHOR]

Thermal link is an important carrier used to transfer the cooling capacity and suppress the temperature fluctuation in cryostat. To balance these two points, it is usually necessary to find the optimum thermal link parameters. This paper establishes a model for the cryocooler cold head-thermal link-second flange based on a cryostat. Utilizing the response surface method, response equations correlating thermal link parameters with the temperature and its fluctuations of the second stage flange are developed at the lowest temperature of cryocooler. Through dual-objective optimization of cooling capacity transfer and temperature fluctuations at the second flange, the optimal thermal link parameters are determined and experimentally validated based on predicted results. The experimental and predicted values show good agreement with an error of 2 %. The optimized thermal link led a minor temperature increase and a significant temperature fluctuation reduction, decreasing from 230mK at the cold head to 2.900mK at the second flange, achieving a 98.74 % reduction. Furthermore, compared with non-optimization structure, the optimization one has further lowered the temperature fluctuation at the second flange from 4.000mK to 2.900mK with 27.5 % improvement. These results show that the present methods are reliable and useful to help to realize highly stable low-temperature environment in cryostat. [ABSTRACT FROM AUTHOR]

For 70% low-floor trains on the light rail lines in Changchun, a multi-linkage forced steering device (FSD) is developed aiming at relieving the independently rotating wheelset (IRW) excessive flange wear and improving IRW bogie system running safety on curve line. This FSD employs guiding mode of steering four independently rotating wheels separately in a two-axle bogie, that is, four FSDs are employed to work together to realize the steering of a two-axle bogie. One side of an FSD is connected to the axle of an independently rotating wheel while the other side is attached to the front or rear vehicle body. When train passes through curve, the yaw angle between the IRW bogie and the front or rear carbody drives the linkage system to rotate to guide the independently rotating wheel towards its radial position. The coupled vehicle-track dynamics model for a 6-module single-type low-floor light rail train is developed and simulations of the train passing through tangent and curved tracks with and without FSD proposed are carried out. The results indicate that the FSD can improve the IRW restoring capability on tangent track and curve negotiation performance on whether sharp, medium, or large curved track. For example, passing through a curve with a radius of 200m, the IRW friction work has the biggest drop by 62.07% and the wheelset attack angle is second with a reduction rate of 55.02%. Adopting of larger steering stiffness, smaller steering clearance, and lever ratio greater than the ideal value can guarantee the higher steering ability of FSD. Besides, lower longitudinal stiffness of the trailer primary suspension is recommended because it can also enhance the steering ability of the FSD. [ABSTRACT FROM AUTHOR]

A slim-floor composite beam's structural performance relies on the composite action provided by shear connectors. However, the information on the performance of composite slim-floor beam with HSTs connectors in flexural in term of moment capacity, shear interaction and ductility still needs to be clarified. Thus, six specimens of the composite beams with square and rectangular HSTs with two different beam sections, I and inverted T, were tested. The main failure was found to be concrete crushing in the area of the connectors. HST connectors prevented the concrete slab from uplifting, particularly in the specimens without a top flange. Subsequently, this increased moment capacity to 230% and 152% for inverted T and I-beam sections, respectively. Furthermore, ductility behavior was also improved and met EC4 requirements. The degree of shear interaction was increased from 0.4 up to 0.9 compared to the beam without HST. The predicted results from the suggested procedure to estimate moment capacity agreed well with the experimental results, with a maximum difference of 7% in the I-section specimen. In contrast, the predicted value for the inverted T specimen overestimates about 26%. Overall, the beam with the HST shear connector significantly improved the flexural performance of the composite slim floor beam. [ABSTRACT FROM AUTHOR]

Purpose: In response to the challenges posed by the conventional manual flange docking method in the LNG (Liquefied Natural Gas) loading process, such as low positioning accuracy, constraints on production efficiency and safety hazards, this study analyzed the LNG five-axis loading arm's main functions and structural characteristics. Design/methodology/approach: An automated solution for the joints of the LNG loading arm was designed. The forward kinematic model of the LNG loading arm was established using the Denavit–Hartenberg (D-H) parameter method, and its workspace was analyzed. The Newton–Raphson iteration method was employed to solve the inverse kinematics of the LNG loading arm, facilitating trajectory planning. The relationship between the target position and the joint variables was established to verify the stability of the arm's motion. Flange center identification was achieved using the Hough transform function. Based on the ROS platform, combined with Gazebo and Rviz, an experimental simulation of automatic docking of the LNG loading arm was conducted. Findings: The docking errors in the XYZ directions were all less than 0.8 mm, meeting the required docking accuracy. Moreover, the motion performance of the loading arm during docking was smooth and free of abrupt changes, validating its capability to accomplish the automatic docking task. Originality/value: The proposed trajectory planning and automatic docking scheme can be used for the rapid filling of LNG filling arms and LNG tankers to improve the efficiency of LNG transportation. In guiding the docking, the proposed automatic docking scheme is an accurate and efficient way to improve safety. [ABSTRACT FROM AUTHOR]

Cemented and mechanically clamped types of end fittings (fitting-C and fitting-M) are commonly used in transformer bushings. During the Luding Ms 6.8 earthquake that occurred in China on September 5, 2022, all transformer bushings with the two types of end fittings in a 500 kV substation were damaged. Post-earthquake field investigations were conducted, and the failures of the two types of bushings were compared. Two elementary simulation models of the transformer-bushing systems were developed to simulate the engineering failures, and further compute their seismic responses for comparison. The results indicate that the hitch lugs of the connection flange are structurally harmful to seismic resistance. Fitting-M can decrease the bending stiffness of the bushing due to the flexible sealing rubber gasket. Since it provides a more flexible connection that dissipates energy, the peak accelerations and relative displacements at the top of the bushing are significantly lower than those of the bushing with fitting-C. Compared with fitting-C, fitting-M transfers the high-stress areas from the connection flange to the root of the porcelain, so the latter becomes the most vulnerable component. Fitting-M increases the failure risk of the low-strength porcelain, indicating the unsuitability of applying it in high-intensity fortification regions. [ABSTRACT FROM AUTHOR]

Steel I-beams are often strengthened by welding steel cover plates to the bottom flanges of the beams. However, very limited studies have been conducted on the effect of welding heat on the behaviour of I-beams reinforced while under load. This paper presents a finite element (FE) analysis-based study on the behaviour of preloaded steel I-beams reinforced with cover plates welded to the bottom flanges of beams, considering welding procedure simulation. FE analysis is conducted to study the effects of welding heat, welding sequence, and weld length on the residual welding deformation and behaviour of steel I-beams reinforced while under load. It is observed that an appropriate welding sequence and weld length can reduce the residual lateral deformations induced from welding of a reinforcing plate to the bottom flange of the preloaded I-beam and thus control the unfavourable welding effects. Based on the analyses, a welding segment length of L/9, where L is the length of the beam, is recommended for practical applications. In addition, FE analysis shows that the direction and magnitude of the initial geometrical imperfection can change the value and direction of the residual deformation resulting from welding. Furthermore, it is observed that preloading does not have any significant effect on the behaviour and ultimate capacity of the I-beam reinforced at a preload level up to 50% of the strength of the unreinforced beam. Also, when compared with the current standards AISC 360-16 and CSA S16-9, FE analysis of reinforced steel I-beams considering welding simulation shows that the current standards significantly overpredict the moment capacities of the reinforced beams when the top flange loading effect is not considered. [ABSTRACT FROM AUTHOR]

The past decade has seen rapid development of offshore wind energy around the world. Furthermore, to improve the efficiency of power generation, wind turbine development has been trending towards increasingly large and tall turbines. These developments call for innovations in the form of wind turbine towers to address the challenges faced by existing tower forms (e.g., steel tubular towers and prestressed concrete towers) in structural adequacy, construction efficiency and/or maintenance. This paper presents a new form of hybrid wind turbine towers which possesses many important advantages over the existing tower forms and are particularly suitable for large offshore wind turbines. The new hybrid towers, termed herein hybrid FRP-concrete-steel prestressed double-skin wind turbine towers or PDSWTs, are prefabricated in segments and then assembled on site. The PDSWT segments are a variation of hybrid FRP-concrete-steel double-skin tubular members (DSTMs), and they consist of an outer confining tube made of fibre-reinforced polymer (FRP), a thin steel inner tube with welded shear studs, prestressed concrete between the two tubes, and flanges welded at the ends of the steel tube. The onsite assembly of the tower involves mainly connecting the steel flanges of two adjacent segments using high-strength bolts, and installing prestressed tendons through the whole tower. In this paper, the rationale behind the development of PDSWTs is first explained, followed by a discussion of the design considerations and future research needs to facilitate the practical applications of the new tower form. [ABSTRACT FROM AUTHOR]

A detailed study of the behaviour of concrete-filled rectangular tubular flange girders (CFRFGs) was undertaken. The CFRFGs were steel beams in which the top flange plate is replaced with a concrete-filled steel section, resulting in greater load-carrying capacity and lateral torsional buckling resistance compared with a regular steel beam of similar proportions. They are complex members and their behaviour is governed by several interrelated parameters, which were studied in this work. Using the Abaqus program, a three-dimensional finite-element (FE) model was developed to investigate the flexural behaviour of simply supported CFRFGs. Using available experimental results, the computational model was validated and then used to study the influence of the most salient properties on the overall response. Based on a fundamental assessment of the behaviour, a simplified analytical model was developed to predict the capacity of these types of section in a way that is suitable for designers. The results were compared with those from the FE analysis and it was found that the analytical model is capable of providing an accurate depiction of the behaviour and the bending moment capacity. [ABSTRACT FROM AUTHOR]

Investigations carried out on cellular steel beams so far were mainly focused on the behavior of non-composite homogeneous sections. Hybrid I-beams are built-up sections where different steel grades are used for flanges and web parts. But perforated hybrid hot-rolled I-sections, where the top and bottom T sections would have different steel grades, can be achieved due to their cutting process. This paper presents a comprehensive parametric study focusing on the inelastic behavior of hybrid and homogeneous cellular steel beams made from hot-rolled parent sections. Finite element modeling using ABAQUS software was employed to validate previously tested hybrid and homogeneous cellular steel beams made from hot-rolled sections. To observe the effect of hybrid sections; the results of hybrid cellular steel beams were compared to the homogeneous ones of the same geometry but with different materials property. A broad spectrum of parent sections (section ratio), restraining conditions, spacing to opening ratio, span lengths, and various steel grades were included in the analysis. Results showed that the upper Tee is mainly the governing part in cellular beams. Moreover, the use of hybrid cellular beams with successive steel grades showed more compatible results compared to sections with non-successive grades for both restrained and unrestrained sections failing under global buckling. According to Eurocode 3 design rules, a set of modified equations were proposed to be used for the Lateral Torsional Buckling resistance calculations of hybrid cellular beams made from hot-rolled sections. [ABSTRACT FROM AUTHOR]

Uncertainty analysis is essential for estimating variability within specified tolerances, particularly in three-dimensional (3D) assembly tolerance analysis. This study introduces a novel analytical approach for assessing assembly deviations, integrating the Jacobian–Torsor model with the bootstrap technique. The Jacobian–Torsor model combines the efficiency of representing tolerances with the adaptability of the Jacobian matrix for their propagation. This computerized method, based on the unified Jacobian–Torsor approach, focuses on cam-clamping devices, specifically the fastening flange component. The novelty of this study lies in the application of the bootstrap technique, a Monte Carlo Simulation approach, for uncertainty analysis to estimate variability within specified tolerances. A comprehensive comparison of statistical methods—bootstrap, stratified sampling, Bayesian statistics, and analytical methods—demonstrates the advantages of the Bootstrap approach. The results emphasize its user-friendliness and precision, even with complex shapes. The primary aim is to highlight the utility of the unified Jacobian–Torsor method for tolerance analysis. An experiment involving the fastening flange assembly illustrates the practical application of this approach. The findings confirm the effectiveness of the proposed method, demonstrating its accuracy and reliability for cam-clamping devices in real-world assembly scenarios with intricate geometries. [ABSTRACT FROM AUTHOR]

The classical theory of folded developables suggests that curved crease folding can be applied to sheet metal of high strength to manufacture parts with complex geometries. However, its application has been limited to sheet metals with low strength and requires grooving or perforation of the material at the fold lines. Applying the geometrical concept otherwise remains unexplored despite its potential in sheet metal-intensive industries like automotive, transportation, and construction. The current study introduces a novel sheet metal forming technique called developable forming. The theory of folded developables is applied to design a die tool for flange drawing a developable-shaped steel sheet. A developable connection is produced from high-strength material without resorting to thickness accommodation techniques. Experimental findings establish that the novel process does not follow the premises of the theory of folded developables. New shape effects are observed and the terms curving and coning are introduced to describe these. Additionally, significant redundant strains are identified in the flange, highlighting the different deformation modes in the developable forming process. A higher formability is achieved for a material with limited uniaxial elongation highlighting the need for further investigation on the mechanisms involved in the novel process. [ABSTRACT FROM AUTHOR]

Expanding the use of 6xx aluminum alloy series in various industries is challenging due to the need for cost-effective welding processes and optimal settings to ensure high-quality joints. The present research focused on the comparison of joint performance of the pipes and plates using tungsten inert gas (TIG) and friction stir welding (FSW) The AA6082 alloy material is used for pipes and plates used in the study. Various techniques were utilized, including hardness and tensile tests, and microstructural examinations. Using a scanning electron microscope (SEM), the surface fracture of the specimens that failed under tensile tension was also examined. The present research also included the economic impact on the welding processes used. Results demonstrated that the weld obtained using FSW was defects free whereas, internal flaws were seen in TIG welded samples. The hardness value increased over the base material (BM) for the FSW and TIG by 31-35% and 46-40%, respectively. The FSW joint was welded at a maximum UTS of 3 mm/min and a rotational speed of 3000 rpm. FSW can create the AA60682 flange joints more efficiently and effectively than fusion welding procedures like TIG processes in pipeline applications. For AA6082 flange joints, overall total cost comparisons between FSW and TIG were also made. [ABSTRACT FROM AUTHOR]

In the context of versatile and environmentally friendly joining techniques, joining by forming has proven to be a very useful tool. From this category, hemming is widely used for sheet metal parts like car body panels. Still, hemming of concave and convex geometries represents a challenge for conventional hemming as well as for the more flexible roller hemming. Especially for smaller radii and greater flange lengths, these methods can reach their limits. In the present work, incremental sheet forming (ISF), a flexible forming process without dedicated tools and high formability, is utilized to implement the hemming process. Due to its local and incremental deformation characteristics, a favorable material flow in the flange area is expected, which might prevent cracking and wrinkling. Therefore, the material flow in ISF-hemming will be investigated. Closed circular specimens with radii of 50 mm and 200 mm and varying flange lengths are analyzed. Conclusions about the material flow are drawn by measuring the change in sheet thickness and elongation of the flange. The results show that, for stretch hemming, considerable thinning and elongation of the flange takes place and no cracking is detected. For shrink hemming, significant thickening of the flange and elongation in radial direction is observed, which suppresses wrinkling. [ABSTRACT FROM AUTHOR]

Herein, we present a finite element method (FEM) based curing analysis for predicting the process-induced deformation (PID) of CFRP woven composites using shell-type elements. This method can efficiently consider various fabric parameters and stacking sequences, even for complex structures. For woven composite plates and L-shaped flanges, FEM-based PID prediction using shell elements reduced computation times by 50–59% compared to solid elements, while maintaining acceptable accuracy with relative errors of 0.17–7.35%. Furthermore, the impacts of various fabric parameters and stacking sequences on the PID of woven composites are analyzed in detail. The main finding is that the variation in material properties due to fabric parameters and stacking sequences significantly impacts the PID of woven composite structures. This prediction method can be applied in the design of composite structures and molds, thereby enhancing the dimensional precision and performance of composite structures. [ABSTRACT FROM AUTHOR]

This study investigated the seismic performance and self-centering behavior of a three-story steel frame equipped with self-centering brace (SCBs) using pseudodynamic tests aided by OpenSees version 2.5.7 and OpenFresco version 2.7.0. The three-story self-centering braced frame (SCBF) was simplified to a three-story shear building model, and a generic experimental element with three nodes with horizontal degrees of freedom was used to establish a two-dimensional (2D) numerical model. The input ground motions were scaled to a service level earthquake (SLE), design basis earthquake (DBE), maximum considered earthquake (MCE), and a very rare earthquake (VRE) with 63%, 10%, 2%, and 0.5% probability of exceedance in 50 years, respectively. The test results demonstrated the excellent seismic performance and self-centering behavior of the SCBF. The maximum story drift ratio and maximum residual story drift ratio of the SCBF under a VRE were 1.91% and 0.119%, respectively, below the thresholds of 2.0% and 0.5%. The SCBs provided more than 90% of the initial lateral stiffness of the SCBF and dissipated approximately 55% of the seismic input energy. The seismic performance of the SCBF satisfied the no-damage criterion under an SLE and DBE. Although the columns in Story 1 yielded under an MCE and VRE, no visible residual deformation of the column flanges was detected in Story 1 after the tests. In addition, the maximum residual drift ratio of Story 1 was only 0.066%. Therefore, the columns in Story 1 only required simple and quick reinforcements before being usable. Unexpected factors, such as the fit-up tolerances around the pins, out-of-sync activation of the SCBs in the same story, residual deformation of the SCBs, and the out-of-sync activation of the two groups of disc springs in the same SCB, did not affect the seismic performance and self-centering capacity of the SCBF. [ABSTRACT FROM AUTHOR]

This study presents a novel approach to enhancing the progressive collapse resistance of a fully welded joint (FWJ) by introducing sliding inner cores within the joint, which is referred to as the FWJ with sliding inner cores (FWJS). Two specimens were prepared and designed with additional consideration of composite action of the slab. Quasi-static tests and refined numerical simulations were conducted to analyze the damage mode, deformation behavior, strain distribution patterns, internal forces, and resistance development in both specimens. The test results revealed that the first fracture occurred in the tensile beam flanges for both FWJ and FWJS specimens, whereas the FWJS specimen exhibited delayed crack of the tensile beam flange compared to the FWJ specimen. The FWJS specimen demonstrated better utilization of the catenary mechanism during the flexural–catenary combined stage. Additionally, in the elastic, elastic–plastic, plastic, and flexural–catenary combined stages, the addition of the sliding inner cores in the FWJS specimen significantly enhanced its resistance by 15.6%, 22.3%, 23.4%, and 70.2%, respectively. It is also revealed that the response of the sliding inner core consisted of bending, transition, and full tension stages, which was shown to effectively replace the fractured beam flange in redistributing the internal forces. Based on the analysis of the working mechanism and numerical parametric analysis, optimal values for the 10 design parameters of the FWJS are suggested, and a comprehensive design procedure for the FWJS is proposed. [ABSTRACT FROM AUTHOR]

The relative rotation angle between two cabins should be automatically and precisely obtained during automated assembly processes for spacecraft and aircraft. This paper introduces a method to solve this problem based on distributed vision, where two groups of cameras are employed to take images of mating features, such as dowel pins and holes, in oblique directions. Then, the relative rotation between the mating flanges of two cabins is calculated. The key point is the registration of the distributed cameras; thus, a simple and practical registration process is designed. It is assumed that there are rigid and scaling transformations among the world coordinate systems (WCS) of each camera. Therefore, the rigid-correct and scaling-correct matrices are adopted to register the cameras. An auxiliary registration device with known features is designed and moved in the cameras' field of view (FOV) to obtain the matrix parameters so that each camera acquires traces of every feature. The parameters can be solved using a genetic algorithm based on the known geometric relationships between the trajectories on the registration devices. This paper designs a prototype to verify the method. The precision reaches 0.02° in the measuring space of 340 mm. [ABSTRACT FROM AUTHOR]

Manufacturing of thin-walled components with protrusions holds importance for the advancement of extrusion technology, expanding the application scope of extrusion processes and achieving lightweight equipment. To accomplish these objectives, a novel two-step combined extrusion process is proposed, drawing on numerous research achievements and theories in flange forming. Detailed analysis of metal flow characteristics during extrusion is conducted using finite element simulation, and the strain heterogeneity index is introduced to quantitatively evaluate the influence of different process parameters and die cavity dimensions on the forming results. The results indicate that the forming quality of the protrusions depends on lower extrusion speeds, appropriate friction coefficients, and rounded die inlet corners. Furthermore, the generation mechanism of defects during the forming process is investigated through the analysis of billet and die cavity dimensions, leading to the establishment of a 3D forming limit diagram. Finally, multiple sets of physical experiments are designed and conducted to validate the feasibility of the forming process and simulation results. [ABSTRACT FROM AUTHOR]

This article presents research results regarding the development of a new manufacturing technology for an element assigned to belt conveyor flights in the extractive industry through hot die forging (of a forging with a double-sided flange) instead of the currently realized process of producing such an element by welding two flanges onto a sleeve or one flange onto a flange forging. The studies were conducted to design an innovative and low-waste technology, mainly with the use of numerical modelling and simulations, partially based on the current technology of producing a flange forging. Additionally, during the development of the forging process, the aspect of robotization was considered, both in respect of the forging tools and the process of transportation and relocation of forging between the impressions and the forging aggregates. A thermo-mechanical model of the process of producing a belt conveyor flight forging with deformable tools was elaborated by means of the Forge 3NxT program. The results of the conducted numerical modelling made it possible, among other things, to develop models of forging tools ensuring the proper manner of material flow and filling of the impressions, as well as temperature and plastic deformation distributions in the forging and also the detection of possible forging defects. For the technology elaborated this way, the tools were built together with a special instrument for flanging in the metal, and technological tests were performed under industrial conditions. The produced forgings were verified through a measurement of the geometry, by way of 3D scanning, as well as the hardness, which definitively confirmed the properness of the developed technology. The obtained technological test results made it possible to confirm that the elaborated construction, as well as the tool impressions, ensure the possibility of implementing the designed technology with the use of robotization and automatization of the forging process. [ABSTRACT FROM AUTHOR]

In this paper, a new image-correction method for flange joint bolts is proposed. A checkerboard is arranged on the side of a flange node bolt, and the homography matrix can be estimated using more than four feature points, which include the checkerboard corner points. Then, the perspective distortion of the captured image and the deviation of the camera position angle are corrected using the estimated homography matrix. Due to the use of more feature points, the stability of homography matrix identification is effectively improved. Simultaneously, the influence of the number of feature points, camera lens distance, and light intensities are analyzed. Finally, based on a bolt image taken using an iPhone 12, the prototype structure of the flange joint in the laboratory is verified. The results show that the proposed method can effectively correct image distortion and camera position angle deviation. The use of more than four correction points not only effectively improves the stability of bolt image correction but also improves the stability and accuracy of bolt-loosening detection. The analysis of influencing factors shows that the proposed method is still effective when the number of checkerboard correction points is reduced to nine, and the average error of the bolt-loosening detection result is less than 1.5 degrees. Moreover, the recommended camera shooting distance range is 20 cm to 60 cm, and the method exhibits low sensitivity to light intensity. [ABSTRACT FROM AUTHOR]

In this study, OBC joint is improved by incorporating one web, two flanges, and two additional bolts, putting forward a novel semi-rigid joint referred to as IBC joint. Finite element models of both OBC and IBC joints are established and the former is validated based on previous research. Subsequently, a total of 84 numerical models is utilized to investigate and compare the mechanical behaviors of OBC and IBC joints, taking into account different thicknesses of side plate and flange as wll as various loading conditions. The numerical results indicate that: (I) in comparison to OBC joints, the IBC joints exhibit significant enhancements in strong axis bending performance and axial tensile performance, including average enhancement ratios of 48%, 67%, 44%, and 19% in initial strong axis bending stiffness, ultimate strong axis bending moment, initial tensile stiffness and ultimate tension, respectively; (II) compared to OBC joints, the IBC joints demonstrate reduced capacity in axial torsional resistance and axial compressive performance, with mean decline ratios of 54%, 39%, 14%, and 7% in initial torsional stiffness, ultimate torque, initial compressive stiffness and ultimate compression, respectively; (III) OBC joints have better weak axis bending performance compared to IBC joints, but this gap decreases remarkably with increasing thicknesses of side plate and flange; (IV) the initial out-of-plane shear stiffness and ultimate out-of-plane shear of the IBC joint exhibit average enhancement of approximately 20% and 10%, respectively, when compared to those of the OBC joint; (V) regarding in-plane shear performance, the initial stiffness of IBC joints exceeds that of OBC joints by an average ratio of 61%, while IBC joints with flange thickness over 10 mm demonstrate significant improvement in ultimate capacity; (VI) The mechanical performance of OBC and IBC joints shows varying degrees of improvement with an increase in the thicknesses of side plate and flange. [ABSTRACT FROM AUTHOR]

In the current research work, the shear capacity of the cold-formed steel (CFS) three-bolted clip angle (CA) beam-to-column moment connection (3BM) is investigated with 45 laboratory test results. The 3BM connection comprises a three-bolted CA connector that connects the web portions and a bolted flange cleat (FC) that connects the flange portions of the beam and column; in comparison, the three-bolted shear connection (3BS) connects only the web portions of the beam and column. The presence of the FC improved the shear strength of the 3BM connection over the 3BS connection and it is quantified using a coefficient called the "rigidity factor (β)." A shift in the failure mode of CAs from shear local buckling in a 3BS connection to tearing failure in a 3BM connection was observed as the FC resists beam torsional deformation and delays the early local buckling of the CA. The existing design shear equation of the 3BS connection is improved by expressing it as a function of CA failure modes. Following the same trend, the existing design shear method for the CFS moment connection is improved by incorporating the failure modes of the CA boundary conditions along with the geometric and material properties of both the CA and FC for the present 3BM connection. In addition, an empirical shear design equation is suggested for the 3BM connection. The design factors of the proposed 3BM shear equations for load and resistance factor design, limit state design, and allowable strength design methods were evaluated from the reliability study. [ABSTRACT FROM AUTHOR]

During the major overhaul of a chemical plant, the pipelines were disassembled and cleaned. Upon reinstallation, an air-tightness test discovered that the flange of the tandem mixer had cracked at the 304 stainless steel (SS) welding joint, affecting normal production. In the present paper, the microstructure of the weld joint was analyzed using SEM equipped with an EDS detector, to explore the corresponding cracking mechanism. The results show that the cracks start on the inner surface of the flange and extend outside. The microstructure in the welding heat affected zone (HAZ) is coarse and carbides are occurring at the grain boundaries, which reduces the strength. The precipitation of carbides at grain boundaries also reduced the Cr content in the crystal, resulting in a decrease in the corrosion resistance of the passivation film on 304 SS. The HAZ showed lower elongation compared to the 304 SS substrate and the fused zone. Under the combined action of stress and corrosive media, the HAZ undergoes stress corrosion cracking. [ABSTRACT FROM AUTHOR]

In this paper, a new segmental blank holder technique was developed. The blank holder force (BHF) was applied on sheet metal independently and effectively by the binder which was divided into double rings. The principle of holding was derivatized by theoretical formulas, thereby proving that the BHF distribution applied by the new binder is more reasonable. Furthermore, combined with numerical simulation, it can be found that the wrinkling was better suppressed. Finally, the effectiveness of the segmental blank holder technique was proven by a series of experiments with AA5754 plate. It is verified that the flange wrinkling was demonstrated to be more eliminated than that using the single blank holder. Compared with 1:2 and 2:1, when the distribution ratio between the outer ring and the inner ring is 1:2 (the applied BHF is 6.9 kN), there has a better-forming quality. [ABSTRACT FROM AUTHOR]

This study aims to propose an improvement to the conventional connection of beam-to-weak axis of H-shaped columns with in-plane load paths and to compare the improved connection with the conventional one. The conventional connection detail consists of continuity plates and face plates, while the improved connection detail, in addition to the previous components, has a plate perpendicular to the column web (middle panel zone) acting as a panel zone. A numerical study using ABAQUS was conducted, and the study results showed that the most appropriate value for the middle panel zone thickness is equal to the column flange thickness, and it should be designed for 30% of the force demand induced by the beam bending moments. Furthermore, the study findings indicated that the proposed connection resulted in an average of 59.5% decrease in the force demands induced to the panel zone in comparison with the conventional connection. In addition, it was observed that the force demand on the face plate experienced the most decrease due to reducing the out-of-plane performance of the face plate in the improved connection models. Moreover, the results showed that the improved connection models experienced lower levels of von Mises stress, approximately 35.7% less than the conventional connection models. [ABSTRACT FROM AUTHOR]

High-pressure grinding rolls (HPGR) have increased their popularity in the minerals industry, since their first application in the 1980s for raw material preparation in the cement industry. Recent advances on the technology have been responsible for putting it in a prominent position among comminution processes, with applications that now range from tertiary crushing stages to pressing iron ore concentrates prior to pelletization. This work reviews some of the recent advances in the technology applied to the minerals industry, including efforts toward improvement on roll lifetime, understanding the effect of progressive roll surface wear on machine performance, alternative lateral confinement systems, the phenomenon of skewing and entirely novel machine designs. Such advances, besides recent insights into the equipment operation, are analyzed, whenever possible, with the assistance of advanced simulation tools, in particular, the discrete element method (DEM). [ABSTRACT FROM AUTHOR]

Purpose: To compare flange depth for a modified scleral pocket (SP) vs no scleral pocket (NSP) technique (Yamane technique) for intrascleral intraocular lens (IOL) fixation. Setting: Instituto de Oftalmología Santa Fe, Santa Fe, Argentina. Design: Prospective, randomized, single-surgeon, observational study. Methods: Eyes with aphakia and no capsular support were included. They were divided into 2 groups: one was programmed for a double-needle flanged intrascleral IOL fixation as originally described by Shin Yamane with NSP and the second group had a modified SP technique. Flange depth was measured with anterior-segment optical coherence tomography (AS-OCT) at 1 month, 3 months, 6 months, and 12 months postoperatively, and the results were compared. Results: Each group comprised 18 eyes of 18 patients, giving a total of 36 flanges per group. The groups were comparable preoperatively. At 12 months, uncorrected distance visual acuity and corrected distance visual acuity (CDVA) were not statistically different for both groups (P = .333; P = .448). Spherical equivalent (SEQ) was not significantly different between groups at 12 months postoperatively (P = .078). AS-OCT revealed a significantly deeper flange position for the SP group at 1 month, 3 months, 6 months, and 12 months postoperatively (P < .05). Conclusions: When performing a double-needle intrascleral IOL fixation in aphakic eyes with no capsular support, a modified scleral pocket technique provides a significantly deeper flange position with no difference in CDVA or SEQ 12 months postoperatively. [ABSTRACT FROM AUTHOR]

Nestlings normally exhibit a mix of traits that attract parental care, such as postural and vocal begging and carotenoid‐based mouth colouration. These signals are hypothesised to be signs of nestling needs (vocal begging) and quality (mouth colouration). Therefore, we hypothesised that broods, where nestlings beg for less time and display more saturated carotenoid‐based mouth colouration, would have lower nestling mortality. We tested these predictions in two wild blue tit (Cyanistes caeruleus) populations. The breeding success (here defined as the proportion of eggs that produced fledglings) was related to nestling mouth flanges' carotenoid‐based colour saturation. This means that blue tits that raised nestlings with more coloured flanges had a higher within‐population breeding success. Time spent in vocal begging, by contrast, was not associated with breeding success. Hence, our findings reveal that some communication signals displayed by nestlings (carotenoid‐based colouration) predict breeding success, in our study mostly reflecting the proportion of eggs that hatched, while begging intensity does not, probably because the former reflects a better maternal pre‐laying condition and nestling physiological status in the mid‐term. [ABSTRACT FROM AUTHOR]

Consideration of an eccentric load introduction in the buckling check acc. to the reduced stress method in EN 1993‐1‐5 – part 2: numerical studies Part 1 of this article describes the large‐scale buckling tests under biaxial loading carried out at the Technical University of Munich in the course of projects, as well as their recalculation and modeling using the finite element method. The numerical model described in part 1 was extended and slightly adapted for the following parameter study. The flange is taken into account in the modeling so that the clamping effect of the freely rotating flange is included. Without the connection of a bottom plate or flange, no eccentric load can be introduced into the web, so some clamping effect is essential and therefore the assumption of Navier's support at the edge of the eccentric load introduction does not apply. The results of the numerical parameter study with the model are briefly summarized in this part 2. These are then compared and evaluated with the reduced stresses method acc. to DIN EN 1993‐1‐5:2019. The comparison shows that an enormous economic potential for the buckling analysis can already be achieved by considering a freely rotating flange for I‐sections. Therefore, an approach is developed and presented that allows the consideration of an eccentric load introduction in the buckling analysis and at the same time conservatively accounts for the clamping effects that occur. [ABSTRACT FROM AUTHOR]

The foundation ring (FR) is a steel component embedded within the concrete of a wind turbine foundation, playing a pivotal role in connecting the wind turbine tower to the foundation structure. In this paper, the FR–foundation connection is equivalent to the exposed foundation and the shallow foundation by analyzing the anchorage characteristics of the foundation ring. Based on the ABAQUS concrete damaged plasticity model, full-scale modeling of the wind turbine foundation is carried out. The influence of embedment depth, ring radius and base flange width of the foundation ring on moment capacity is simulated. Based on the observed stress distributions under ultimate loads, analytical expressions were proposed to estimate the variation law of anchorage load-bearing capacity in the ultimate load state. Compared with the numerical simulation, the average errors under different influencing factors are 8.2%, 9.6% and 10.8%, respectively. The results indicate that the base flange provided the majority of the moment capacity, though the contribution of the sidewall increased to 25–50% that of the base flange in later stages. [ABSTRACT FROM AUTHOR]

This study experimentally and computationally investigates the heat transfer capability of supercritical carbon dioxide (sCO2) single jet impingement. The evaluated jet Reynolds number range is between 80,000 and 600,000, with a nondimensional jet-to-target surface spacing of 2.8. CO2-impinging jet stagnation conditions were maintained at approximately 200 bar and a temperature of ~400 °C for most experiments. The goal is to understand how changes in the aforementioned parameters influence heat transfer between the working fluid and the heated surface. Additionally, due to the elevated Reynolds numbers and difference in thermodynamic properties between air and CO2, air-derived impingement correlations may not be appropriate for CO2 impingement; these correlations will be evaluated against experimental sCO2 impingement data. At the time of this study, no sCO2 impingement data was available relevant to sCO2 power cycles. The target surface is a 1.5-in. diameter copper block centered on the 3 mm jet orifice. A mica heating element bolted to the bottom of the copper block provides a uniform heat flux. Thermocouples embedded in the copper block are used to determine the surface temperature. Nusselt numbers obtained from experimental sCO2 test data are compared to area-averaged Nusselt numbers from air-derived correlations. The comparisons showed that air correlations drastically underpredict the heat transfer when sCO2 is used as the working fluid. A modified sCO2 correlation using experimental data at discussed conditions is derived based on an existing air correlation. A CFD study is also performed to further investigate sCO2 heat transfer characteristics, and assess the numerical model applicability to this problem type. [ABSTRACT FROM AUTHOR]

Taking the maximum contact pressure as the objective function for, the optimal design model of the offshore flange connector was established to analyze the impact of the flange cone's angle and the curvature radius of the lenticular gasket's contact surface on the sealing performance of the connector. An optimized three-dimensional model of the offshore flange connector was constructed using the MATLAB software's fmincon function to obtain the optimal size of the cone angle and curvature radius. The maximum contact pressure and maximum equivalent stress values of the nonoptimized and optimized offshore flange connectors under the cross combination of two design pressures and six operating temperatures were analyzed by Workbench software, and the sealing performance of the non-optimized and optimized offshore flange connectors was compared according to the sealing judgment basis. The results show that compared with the previously studied offshore flange connector, the sealing structure of optimized offshore flange exhibits maximum increase in contact pressure increase but maximum decrease in equivalent stress. Under actual operating circumstances, the optimized offshore flange connection performs better in sealing and is less prone to breakage. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the flange properties of different iris hooks. Setting: Vienna Institute for Research in Ocular Surgery (VIROS), Hanusch Hospital, Vienna, Austria. Design: Laboratory study. Methods: The flanging properties of 4 different iris hooks made from polypropylene (PP), elastic polymer (EP), and nylon were investigated with different heating distances and both with and without forceps gripping. The maximum diameter of the flanges was measured, and the shape of the flanges was evaluated. Results: Although both nylon and EP iris hooks had too small flange diameters for intrascleral fixation, PP iris hooks had a sufficient flange diameter (>330 mm) and mushroom-like shape. Furthermore, in PP hooks, heating distance was directly proportional to flange diameter. Conclusions: The findings of this study suggest that only PP iris hooks are suitable for flanged intrascleral fixation, which is off-label, to secure adequate fixation. [ABSTRACT FROM AUTHOR]

This study investigates flange fracture formation in unconventional incremental radial extrusion. This manufacturing technique involves using rings with a gradually increasing inside diameter for constraining the free flow of material in the radial direction. As a result, the shaped flange has a constant thickness and a significantly larger diameter than that formed using the standard extrusion process conducted without the use of rings. EN AW 6060 aluminum alloy tube sections were used as the billet material, and the extrusion process was conducted under cold forming conditions at ambient temperature. For the determination of material fracture initiation, a new method was proposed involving the analysis of strain, strain rate and values of the normalized Cockcroft–Latham fracture criterion integral. The main advantage of the new method is that it allows for the prediction of fracture initiation via only FEM results analysis, i.e., it is not necessary to carry out additional experiments aimed at calibrating or determining limit parameters of a given material. It was shown that the occurrence of differences in the distribution of the above-mentioned parameters coincided with flange fracture initiation. [ABSTRACT FROM AUTHOR]

The reaction of a radial flexible ring with flanges in the supports of machine rotors to radial displacement has been studied. Two models of deformation and contact interaction of an elastic element with two rigid bodies positioned inside and outside of the ring have been developed. These models are based on variational statements with respect to the unknown forces and displacements. The options of gap and offset on both sides of the contact between the ring and the rigid bodies have been considered. A substantially nonlinear static reaction of the ring to radial displacement has been established. Radial reaction curves have been obtained across a wide range of design parameters, enabling a well-justified choice of an elastic damper with the desired stiffness properties. [ABSTRACT FROM AUTHOR]

An accurate and reliable estimation of the transformation matrix between an optical sensor and a robot is a key aspect of the hand–eye system calibration process in vision-guided robotic applications. This paper presents a novel approach to markerless hand–eye calibration that achieves streamlined, flexible, and highly accurate results, even without error compensation. The calibration procedure is mainly based on using the robot's tool center point (TCP) as the reference point. The TCP coordinate estimation is based on the robot's flange point cloud, considering its geometrical features. A mathematical model streamlining the conventional marker-based hand–eye calibration is derived. Furthermore, a novel algorithm for the automatic estimation of the flange's geometric features from its point cloud, based on a 3D circle fitting, the least square method, and a nearest neighbor (NN) approach, is proposed. The accuracy of the proposed algorithm is validated using a calibration setting ring as the ground truth. Furthermore, to establish the minimal required number and configuration of calibration points, the impact of the number and the selection of the unique robot's flange positions on the calibration accuracy is investigated and validated by real-world experiments. Our experimental findings strongly indicate that our hand–eye system, employing the proposed algorithm, enables the estimation of the transformation between the robot and the 3D scanner with submillimeter accuracy, even when using the minimum of four non-coplanar points for calibration. Our approach improves the calibration accuracy by approximately four times compared to the state of the art, while eliminating the need for error compensation. Moreover, our calibration approach reduces the required number of the robot's flange positions by approximately 40%, and even more if the calibration procedure utilizes just four properly selected flange positions. The presented findings introduce a more efficient hand–eye calibration procedure, offering a superior simplicity of implementation and increased precision in various robotic applications. [ABSTRACT FROM AUTHOR]

This study aims to describe a new technique of indirect cyclopexy in the treatment of cyclodialysis. Cases who had cyclodialysis for more than 3 h of extent and were resistant to medical treatment underwent flanged prolene cyclopexy (FPC) technique. Five cases were included in this study. Mean duration between the initial surgery and FPC was 4.6 ± 4.3 months. Hypotony maculopathy was present in all cases. All cases underwent FPC in combination with pars plana vitrectomy and silicone oil injection. Circumferential FPC was applied in four cases, while focal FPC was performed in one case. Postoperatively, no complications occurred, visual acuity increased in four cases, and cyclodialysis closed in all cases. In the follow-up, silicone oil was removed in three cases, but silicone oil could not be removed in two cases with ongoing hypotony. Preliminary results showed that FPC is a promising technique in the surgical treatment of cyclodialysis. [ABSTRACT FROM AUTHOR]