Support Plate Research Articles

Recent Development on Doubler or Collar Plate Reinforced Square Hollow Section Joints under Brace Axial Load

Tubular joints are crucial structural components in steel tubular truss structure. Doubler or collar plate reinforcement has gained popularity in strengthening square hollow section (SHS) joints on the chord. But the existing design rules for the reinforced tubular joints require improvement. This paper reviews literature on SHS joints strengthened by doubler or collar plate. Key geometrical parameters, structural behaviour and failure modes of reinforced SHS joints reported in literature were discussed. Design methods in specifications and literature were evaluated by comparing the design values with experimental results. It was shown that the approach using linear fitting coefficients obtained by key parameters is able to provide a more accurate prediction. The SHS joint strengthening process with doubler plate or collar plate is discussed, highlighting some construction restrains. Finally, the trend and development direction of this field are proposed.

Performance of perforated double steel plate reinforcements in composite shear walls under axial compression

Performance of perforated double steel plate reinforcements in composite shear walls under axial compression

Research on Velocity Feedforward Control and Precise Damping Technology of a Hydraulic Support Face Guard System Based on Displacement Feedback

The hydraulic support face guard system is essential for supporting the exposed coal wall at the working face. However, the hydraulic support face guard system approaching the coal wall may cause impact disturbances, reducing the load-bearing capacity of coal walls. Particularly, the hydraulic support face guard system is characterized by a large turning radius when mining thick coal seams. A strong disturbance and impact on the coal wall may occur if the approaching speed is too fast, leading to issues such as rib spalling. In this paper, a feedforward fuzzy PID displacement velocity compound controller (FFD displacement speed compound controller) is designed. The PID controller, fuzzy PID controller, feedforward PID controller, and FFD displacement speed compound controller are compared in terms of the tracking characteristics of the support system and the impact response of the coal wall, validating the controller’s rationality. The results indicate that the designed FFD displacement speed compound controller has significant advantages. This controller maintains a tracking error range of less than 1% for target displacement with random disturbances in the system, with a response adjustment time that is 34% faster than the PID controller. Furthermore, the tracking error range for target velocity is reduced by 8.4% compared to the feedforward PID controller, reaching 13.8%. Additionally, the impact disturbance of the support system on the coal wall is suppressed by the FFD displacement speed compound controller, reducing the instantaneous contact impact between the support plate and the coal wall by 350 kN. In summary, the FFD compound controller demonstrates excellence in tracking responsiveness and disturbance rejection, enhancing the efficacy of hydraulic supports, and achieving precise control over the impact on the coal wall.

Elimination of Delamination during the Drilling of Biocomposite Materials with Flax Fibers.

The present study focuses on the elimination of delamination during the drilling of a linen-based biocomposite material in epoxy resin used for the manufacture of sports kayaks, depending on the tool material, cutting conditions, and the use of additional wooden support plates. In the present study, HSS (high-speed steel) and Carbide cutting tools without coatings, with the same geometry and two types of cutting conditions (n = 1500 rpm, fn = 0.05 and 0.1 mm/rev) were used. A Sololite-type wooden backing plate was used to aid in reducing delamination. The results show that the additional support plates significantly reduced delamination by up to 80% both at the material inlet and especially at the drill hole outlet. In this study, the use of a lower feed rate (fn = 0.05 mm/rev) per tooth was shown to have a significant effect on reducing the delamination of biocomposite materials with flax fibers, which are generally known to be difficult to machine. The Carbide cutting tool shows significantly better results both in terms of its wear and in terms of delamination of the biocomposite material. The highest delamination was obtained without the use of a backing board at the tool exit after 50 drilled holes of 3509 µm. With the use of a backing board, this delamination decreased to 693 µm after 50 drilled holes.

Effect of horizontal web reinforcement, depth, proportionated loading and bearing plates on shear strength and serviceability of reinforced concrete deep beams

In this paper, the strength, serviceability and failure modes of eleven reinforced concrete (RC) deep beams were evaluated. The small, medium and large-size specimens with heights ranging from 300 to 1250 mm and effective spans from 600 to 2500 mm were tested up to failure under the three-point bending test. The length of loading and bearing plates varied from 100 to 400 mm, and the percentage of horizontal web reinforcement varied between 0.00 % and 0.45 %. Test results revealed that distributed web reinforcement and proportionate loading and supporting plates mitigate the size effect. Further, when the percentage of horizontal shear reinforcement increased, the mode of failure changed from diagonal tension to shear compression. From the test results, it has been concluded that the optimum horizontal web reinforcement was 0.25 % for achieving the highest ultimate and service load. The strength reduction factor of maximum shear force expression of ACI 318–19 [25] code adequate even in the case of deep beams failing in shear compression mode is experimentally validated.

Development of End-Reduced Pre-Flex Girder

Bridges serve to connect spaces where natural terrain or structures restrict the movement of people or vehicles. Various bridge construction methods have been proposed, and the application of preflex construction methods has recently increased. The end-reduced preflex girder is a method that applies preflex construction and compensates for the decrease in structural performance and long-term deflection of the bridge. However, in the existing preflex construction method, compliance with the minimum clearance height regulations in Korea, necessitates an increase in the end plan height, which requires an additional embankment that narrows the driver's view. This study was conducted to verify and evaluate the performance of an end-reduced preflex girder that can increase the structural strength and secure the minimum clearance height by attaching a shear reinforcement plate to the bottom of the lower flange, enabling an economical design.

Vibration Characteristics and Frequency Modulation of Rocket Engine Multiconfiguration Small Pipeline Systems

As the important component of rocket engines, small pipeline systems have the characteristics of being lightweight and having structural complexity and obvious randomness in vibration effects. Mastering the dynamic characteristics of the pipeline systems is a key technical approach to improving the overall lifespan of engines. This study used a noncontact sound pressure sensor for dynamic parameter collection, reducing the experimental errors caused by the accelerometer’s weight and signal line interference, etc., factors. The dynamic characteristic experimental and simulation study was conducted on several types of combined configuration small pipeline systems, including plane pipelines, space pipelines, support plates, and clamps. The errors of the top six modal results were all less than 20%, with a minimum error of 0.5%, proving the correctness and effectiveness of the dynamic characteristic experimental and simulation methods. The modified modeling and FEA methods were used to study the structural optimization of pipeline systems, which can provide engine pipeline systems reasonable guidance for natural frequency modulation and parameter sensitivity results analysis.

Optimized analysis and reinforcement design model for RC/SCC box-section bridges using developed advanced design framework

In recent years, there has been a significant rise in the construction of reinforced concrete (RC) and steel-concrete composite (SCC) box-section bridges. However, design codes do not provide specific design methods for the RC plates of such bridges where the plates experience both intricate forces and moments. The current design approaches are primarily based on conventional one-dimensional beam element theory, which neglects the complex spatial force characteristics of the structural elements, potentially leading to unsafe design. Therefore, it is imperative to address this issue. To bridge this gap, a comprehensive analysis and reinforcement design procedure named as the developed advanced design framework (DADF) is proposed in this study. The spatial analysis of bridges was performed using a refined numerical model, called the spatial grid model (SGM), to consider the structural spatial effects with limited model scales. Subsequently, the internal force corresponding matrix (IFCM) was implemented through Python scripts to determine the most critical internal force combination for an RC plate element. Additionally, the three-layered sandwich model (T-LSM) was employed with limit analysis to automatically design reinforcement for all elements, serving as a practical tool for design. This research demonstrates that the implementation of the DADF can significantly reduce steel reinforcement in the RC plates of such bridges by up to 48 %, and 23 % in total, showcasing the efficiency of the developed framework. Overall, the findings emphasize that the proposed DADF offers a robust procedure for steel reinforcement design of RC/SCC box-section bridges.

Pressed Solid Target Production of 89Zr and its Application for Antibody Labelling.

Zirconium-89 ( 89Zr, t1/2=3.27d) is an important + emitting radionuclide used in Positron Emission Tomography (PET) immuno studies due to its unique characteristics and increased demand due to simple and cost-effective production capacity. Production of 89Zr is achieved primarily through solid natural yttrium targets via different target preparation methodologies, such as electrodeposition, pressed foils, and spark plasma sintering. In this study, we have investigated the pressed solid target methodology. The Yttrium Oxide (Y2O3) powder was pressed to pellet form and stacked over a different back support plate, such as platinum (Pt), niobium (Nb), and tantalum (Ta). The target was irradiated with approximately 12 MeV proton beam for 10-60 minutes at 20µA current. The irradiated target was purified through a solid phase extraction method via hydroxamate-based resin by manual or automatic approach. The purified 89Zr was analyzed using gamma scintigraphy, and specific activity was calculated through Deferoxamine (DFO) chelation. 89Zr radionuclide via pressed target was effectively produced with a production yield of 20-30 MBq/µA.h, and the purification was achieved in 35 minutes with (87.46)% average recovery and >98% purity while using automated purification, but manual purification took 2 hours with (91 ± 2)% recovery and >98% purity. The production yield was comparable to the reported pressed target approach. Deferoxamine (DFO) chelation with 89Zr-oxalate was performed with purity >98% and specific activity of 25-30 µCi/mmol. In this study, we explored the production of 89Zr by pressed targets and purification via manual or automated methods with good radionuclide purity. The chelation with DFO or its analog was performed with good labeling efficiency and stability</p>.

Effect of tail flare of integral support plate on double-wall cooling performance

The tail of the integrated support plate replaces the traditional flame holder to stabilize the flame. To prevent the support plate from being ablated by high-temperature flame, a double-wall cooling structure is set at its tail, and cold air is introduced to cool it. However, the cold air reduces the stability of the flame. To improve the flame stability of the integrated support plate, the rear of the support plate is expanded. The effects of expansion angle on the aerodynamic characteristics of the afterburner and cooling performance of the double-wall are investigated by using the experimentally verified CFD method. The results show that the total pressure recovery factor of the integral afterburner decreases with the increase of the flare angle under the condition of non-afterburning; the flame stability is improved by increasing the flare angle within a certain range; the film covering effect at the upper part of the flame stabilizer gets worse as the flare angle increases, and the overall cooling effect of the double-wall gets worse.

Application of modified Frosch approach for Schatzker typeⅡtibial plateau fractures with posterolateral column

To explore clnical efficacy of modified Frosch approach for Schatzker typeⅡtibial plateau fracture with posterolateral column. From January 2019 to September 2020, totally 11 patients with Schatzker typeⅡtibial plateau fractures with posterolateral column were treated, including 7 males and 4 females, aged from 21 to 49 years old. Modified Frosch approach was adopted for lateral decubitus position, and posterolateral fractures were fixed with support plates or posterolateral screws. Anterolateral fixation with conventional tibial plateau lateral locking plate. Tibial plateau varus angle and posterior inclination angle were measured by X-ray immediately and 12 months after operation, as well as knee motion at 12 months after operation. Knee function at 12 months after operation was evaluated by knee score of Hospital for Special Surgery(HSS). Eleven patients were followed up for 12 to 15 months. Varus angle and inclination angle at immediately after operation ranged from 76° to 86° and 6° to 10°, respectively, and 79° to 88° and 6° to 10°, respectively at 12 months after operation. The range of extension of knee ranged from 0° to 5°, and flexion was 106° to 137° at 12 months after operation. Postoperative HSS knee score at 12 months ranged from 74 to 94 scores, 8 patients were excellent and 3 good. Modified Frosch approach is an effective surgical method for Schatzker typeⅡtibial plateau fracture with posterolateral column. A single incision is used to complete fracture exposure and fixation at two sites, avoiding use of combined incisions, and could obtain good postoperative knee joint function. During operation, popliteal fossa structure should be familiar, and the common peroneal nerve should be protected to avoid injury.

Stabilizacja zboczy podatnych na osuwiska za pomocą kotew rurowych

This paper presents an anchor of a new design, whose properties have been selected to retain the advantages of a tubular anchor over the other anchor types and at the same time, ensure its adaptation to specific conditions associated with slope stabilization. The proposed anchor consists of a steel tube filled with expanding cement mortar. The outer diameter of the tube is 2-3 mm less than the diameter of the borehole, a groove is cut on the outer surface of the tube. A metal rod is placed in the center of the tube at the outer end of which a support plate is installed, and a tie wrench is fixed. The length of the metal rod is equal to the depth of the bore hole, while the length of the steel tube is at least half the length of the borehole. In the process of solidification and expansion of the solution, pressure is created on the walls of the bore hole. Under the influence of pressure, the pipe is opened around the groove and close contact is achieved between the pipe and the borehole surfaces. As soon as the solution hardens, the steel tube is firmly embedded in the concrete, after which the anchor reaches operational capacity. Preliminary tests of the proposed anchor showed that it has a high clamping force (for hard rock conditions - 46-75 kN/m and for soft rock conditions 32-36 kN/m). He has other advantages, namely it does not require special equipment for installation, the inside of a tube is filled with hard concrete-like mass, which hampers the process of corrosion and increases shear strength.

Development of an inertia-driven resonant piezoelectric stack pump based on the flexible support structure

This paper proposes an inertia-driven resonant piezoelectric stack pump based on a flexible support structure to solve the problem that the piezoelectric stack cannot effectively drive the diaphragm pump to transport liquid due to too small output displacement and too high resonant frequency when one end is fixed. Under the inertial force generated by the vibration of the piezoelectric stack’s mass center during its deformation, the whole piezoelectric stack will vibrate with the flexible support structure; and a large displacement and inertial force can be achieved to drive the pump at the resonant frequency. Piezoelectric pumps are designed with a diaphragm pump and a piezoelectric stack based on the flexible support structure. The piezoelectric vibrator includes a piezoelectric stack, a preloading component and a flexible support plate. A fixed support plate and three flexible support plates with different stiffnesses were fabricated and assembled with the same piezoelectric stack and diaphragm pump respectively to construct four piezoelectric pump prototypes with different resonant frequencies. The temperature rise characteristics of the piezoelectric stack were experimentally studied to determine the safe range of the driving voltage and frequency. Then the output performances of the piezoelectric pumps were tested. Under a sinusoidal driving voltage of 100 Vpp, the piezoelectric pump based on the fixed support structure cannot pump water, while the piezoelectric pumps based on the flexible support structure achieved the maximum flow rates of 89.0 ml min−1, 123.4 ml min−1 and 197.4 ml min−1 at the resonant frequencies of 262 Hz, 297 Hz and 354 Hz, and the maximum backpressures of 4.4 kPa, 7.5 kPa and 11.0 kPa at 266 Hz, 309 Hz and 365 Hz.

A full-field structural displacement reconstruction method for large-scale floating rafts in marine propulsion systems

Large-scale floating rafts have been widely applied to marine propulsion. Due to the presence of elastic supports, it belongs to the elastic constraints rather than the fixed constraints found in aerospace and bridge structures. This leads to displacement is no longer just elastic deformation, but also includes some rigid-body displacement. However, the existing displacement reconstruction methods are all based on fixed constraints. To address this issue, an improved modal method (IMM) is proposed. The boundary conditions are extended from fixed constraints to elastic constraints and the displacement field is uniformly described. Firstly, by analyzing the modal characteristics of three types of constraints, the reasons for the failure of the current modal method under elastic constraints are presented. Secondly, the IMM is established based on a dimensionless error function between the discrete strain, finite displacement measurements, and their theoretical values. Finally, the feasibility of the IMM is verified by numerical analysis and experiment tests on an elastic support plate structure with high precision and excellent suitability. This method can be applied to the full-filled displacement reconstruction in large-scale floating rafts of marine propulsion systems, which provides significant engineering value for improving the shafting alignment and the raft attitude balance.

Parameters identification and application of composite plate reinforcement mesh based on DXF data

Abstract This paper presents an algorithm for identifying the process parameters of a laminated plate reinforcement mesh. To accommodate the actual production needs, the computer software of the production line is employed for the identification of parameters and data processing of the DXF steel mesh file. In this context, a C++ programming algorithm is utilized for the identification of the parameters of the imported DXF file, as per the production line’s processing requirements. DXF is an AutoCAD vector graphics exchange file that is available in two storage formats: ASCII format and binary format. The ASCII format is easily readable and therefore, DXF is widely used, with most CAD software capable of reading or outputting DXF files. This paper initially scrutinizes the structural attributes of DXF files, normalizes the design standard of graphics files, and then reads the coordinates of each point of the POLYLINE entity. A parameter identification algorithm is devised to address the issue of steel bar bending in drawings, with the program designed to verify its accuracy.

Modelling the Influence of the Tube Support Plate on the Eddy Current Testing of the Steam Generator: Sensitivity Study &amp; Validation

Eddy current testing (ECT) of Steam Generator (SG) tubes is part of the maintenance program of Nuclear Power Plants. Tube Support Plates (TSP) are usually only considered as extraneous signals for tube inspection. However, for long-term operation of SGs, there is a safety concern related to the build-up of deposits in the TSPs flow holes. The clogging-up of the TSPs flow holes affect the safe thermal-hydraulic operation of SGs. The deposits come from the feedwater train and are mostly iron oxides (magnetite) with a weak electrical conductivity and magnetite permeability.The ability of ECT probes to detect and characterize TSPs deposits is therefore of great interest. The most common and industrial ECT technique, the bobbin coil, averages the surrounding electromagnetic field over 360°, whereas the geometry of tri-foiled and quadri-foiled TSPs, and thus of clogging, is rather complex and non- axisymmetric, hence motivating the evaluation of the performance of conventional ECT rotating probes used for SGs tubes inspection. Although simulation is a powerful tool to support such a study, it requires dedicated models to be made available to NDT experts, and CEA develops ECT physical models in CIVA for this purpose. In addition to standard fast CIVA modules based on 3D semi-analytical or 2D numerical calculations restricted to canonical or axisymmetric parts, respectively, CEA develops a module dedicated to the simulation of SG tube inspection based on a 3D numerical simulation. This module allows tube deformation such as ovalization, bending or tube expansion. It also allows the addition of external objects such as anti-vibration bars, different geometries of tube support plates and now their clogging by deposits. This model is used to study various influent parameters and to perform benchmarks in the framework of a scientific collaboration between the CEA and the IRSN. Here, the specificity of the TSPs and their clogging justifies qualifying the simulation model before evaluating the influence of material and geometry properties of the deposit as well as the performance of the inspection techniques. We present the main features of the simulation module in CIVA, its experimental validation, and the main trends in the distortion of the simulated signal as a function of variation in the clogging description.

Research on noise prediction of steel aluminum mixed structure ship

Abstract In the context of the implementation of the new Ship Noise Level Regulations, it is particularly important to conduct ship noise prediction during the design phase. This article establishes a SEA model using the statistical energy method and VA One software and predicts cabin noise. The impact of non-living quarters, reinforced panels, and interior materials on noise prediction is discussed. The results indicate that using the statistical energy method for noise prediction has a certain degree of accuracy. When establishing an acoustic model, non-residential compartments can be simplified while considering the influence of reinforcement plates and interior materials on the prediction results.

Analysis of labor productivity in reinforced concrete structures using time study methods

The source of the success of a project in fulfilling the three aspects namely cost, quality, and time from one of the existing resources is the productivity of its workforce. The time study method is the right method used to determine the standard time of a job. The average value of productivity on column formwork is 10.65 m2/OH, beam formwork is 46.89 m2/OH, and plate formwork is 73.29 m2/OH. Column reinforcement work 204.51 kg/OH, beam reinforcement work 349.93 kg/OH, plate reinforcement work 287.57 kg/OH. Column casting work 7.96 m3/OH, beam casting work 25.31 m3/OH, plate casting work 15.81 m3/OH. Several factors greatly affect labor productivity. Comparison of the work productivity of reinforced concrete structures in the Ubud Market project based on the calculation results obtained the average productivity coefficient in the field of labor.

Experimental and numerical study on extended endplate beam-column joints after high temperature to resist progressive collapse

This paper presents experimental and numerical investigations on the collapse-resisting behavior of extended endplate beam-column joints after high temperatures. The failure patterns and structural responses of extended endplate (EP) joints after high temperature to resist progressive collapse were first described, and then the effects of fire temperature and temperature duration on their collapse resistance mechanisms were also analyzed in detail. The test results demonstrate that all specimens withdrew from work owing to the serious deformation of endplate bolt holes or the brittle fracture of high-strength bolts, resulting in the catenary mechanisms of EP joints not being adequately developed. Compared with previous studies, it is shown that the fire temperature exerts the most significant effects on the carrying capacities and deformability of EP joints, and the collapse resistance of corresponding assemblies is most sensitive to the fire temperature. However, the temperature durations have an insignificant influence on the development of flexural mechanism resistance, especially for those after 600 °C and 800 °C. Moreover, the corresponding refined FE models in consideration of the damage and fracture of ductile metals have been established to reproduce the structural response of specimens after high temperature. To improve the post-fire collapse-resisting performance of assemblies, both the lateral plate reinforcement and welding reinforcement methods were proposed and compared with the assistance of validated FE models. From a practical viewpoint, the reinforcement with lateral plates is determined as a superior technique for post-fire EP joints against progressive collapse.

Mechanical Characteristics of Cracked Lining Reinforced with Steel Plate–UHPC Subjected to Vertical Load

The steel plate reinforcement method is widely used for strengthening damaged linings. Nevertheless, low durability is one of the disadvantages of the steel plate reinforcement method, which uses epoxy resin as the interface binder. To enhance the load-bearing performance and strengthening effect of steel-plate-reinforced structures, this study introduced ultra-high performance concrete (UHPC) as the reinforcing bonding layer and proposed a novel method for steel plate–UHPC reinforcement of cracked linings. A mechanical performance model test was conducted on a 1/5 scale lining model using a loading test device to evaluate the load-bearing performance and stress deformation of both conventional steel plate and steel plate–UHPC reinforced cracked linings. The characteristics, mechanisms of failure, and impacts of strengthening of the steel plate reinforcement method and steel plate–UHPC reinforcement method for cracked linings were compared. A numerical simulation model was developed to investigate the reinforcement effect of cracked linings using steel plate–UHPC reinforcement. The analysis included examining the influence of steel plate thickness, UHPC bonding layer thickness, and reinforcement timing. Model test results show that the overall damage mode of the steel plate–UHPC-reinforced structure had good elastic–plastic behaviour, and the deformation and damage process under the vertical concentrated load can be divided into four typical phases. Compared with the traditional steel plate reinforcement, the ultimate load-carrying capacity and ductility of the steel plate–UHPC-reinforced structure were increased by 53% and 366%, respectively, showing significantly better load-carrying capacity and deformation performance. Numerical simulation results show that the reinforced structure’s load-carrying capacity and stiffness enhancement rate increased non-linearly with the increase in UHPC layer thickness and steel plate thickness. However, reasonable reinforcement timing exists for steel plate-UHPC reinforcement, and too late reinforcement timing leads to a decrease in structural load-carrying capacity and stiffness enhancement rate.