Plate Shape Research Articles

Research on the Temperature and Thermal Stress of the Roll Quenching Process of Thin Plates

The roll quenching process can be approximated as a high-pressure jet impinging on a high-temperature moving steel plate. The process can greatly improve the strength and overall mechanical properties of the steel plate. However, the cooling uniformity and other factors lead to the problem of poor plate shape after quenching. It is found that in the roll quenching process, the roller conveyor speed has a large influence on the temperature field and stress field. This paper establishes a roll quenching mechanism model, iterates the convective heat transfer coefficient on the steel plate surface through the inverse heat transfer method, and performs a numerical simulation. Through the numerical simulation of the roll quenching process in the high-pressure zone of the steel plate, the temperature and equivalent force change rule of the transient of each position of the steel plate in the thick direction are obtained. It is found that the plate does not reach its maximum value when it is in the quenching zone, but there is some hysteresis that becomes more pronounced as it gets closer to the core. These findings are valuable for regulating the roll-hardening process and maintaining optimal strip surface quality in industrial production environments.

Evaluation of progressive collapse resistance performance of steel OMF with WCPF connections

A welded cover plated flange (WCPF) connection, which is a pre-qualified connection detail improving a weak weld access hole and the ductility of a welded unreinforced flange-bolted web (WUF-B) connection, has a simple and efficient advantage in construction. In this study, a new modelling approach of the WCPF connection by employing 1-D element was proposed for the evaluation of progressive collapse resistance capacity performance. The model was developed by substituting the average width of trapezoidal shapes of cover plates welded to the top and bottom flanges and by assessing the equivalent flange thickness based on the moment of inertia. The proposed model was verified through comparisons with experimental and 3-D numerical results, showing discrepancy within 5.7%. To evaluate the performance of the WCPF connection, a prototype structure was adopted from the previous study for the appraisal of the WUF-B and reduced beam section (RBS) connections. The alternative load path method was performed using an energy-based approximate analysis considering the dynamic effect of sudden column loss. The performance of the structure was evaluated in terms of structural robustness and sensitivity. Furthermore, the results were compared to those of the structures with the WUF-B and RBS connections analyzed in the previous study. The structure with the WCPF connections showed 33% more improved structural robustness and 11% less sensitivity to progressive collapse when one column was removed. In a two-column removal scenario, only the structure with WCPF connections indicated to have proper progressive collapse resistance capacity. The WCPF connection was deemed more reliable than WUF-B and RBS ones.

Sound radiation patterns of the Sarasvati Veena and their relation with the modal behavior of its top plate

The large wooden resonator of the Sarasvati Veena amplifies and radiates the sound in almost all directions. The directional and spatial dependence of this radiation is studied in conjunction with the mode shapes of the top plate of the resonator. Sound radiation patterns are simulated theoretically using the nodal displacement data obtained from the numerical modal analysis of the resonator. The experimental analysis involves the manual plucking of the Veena string. The radiated sound is recorded by placing microphones around the resonator in circular arrays of different radii in the different planes. These combinations of arrays at different distances and planes provide a thorough knowledge of sound radiating out of the resonator. The intensities of different frequencies in the recorded spectral data as functions of direction and distance from the approximate center of the top plate of the resonator are studied. Experimentally measured patterns show the importance of the top plate over the body of the resonator. Theoretical and experimental radiation patterns for different harmonics of the plucked string are compared and a good match is observed. The behavior of the radiating sound in the different planes at different radial distances from the assumed center is discussed.

Pure measures of bending for soft plates.

This paper, originally motivated by a question raised by Wood and Hanna [Soft Matter, 2019, 15, 2411], shows that pure measures of bending for soft plates can be defined by introducing the class of bending-neutral deformations, which represent finite incremental changes in the plate's shape that do not induce any additional bending. This class of deformations is subject to a geometric compatibility condition, which is fully characterized. A tensorial pure measure of bending, which is invariant under bending-neutral deformations, is described in detail. As shown by an illustrative class of examples, the general notion of a pure measure of bending could be useful in formulating direct theories for soft plates, where stretching and bending energies are treated separately.

Enhancement in the dielectric and magnetic properties of Ni2+-Cu2+ co-doped BaFe11Cu1-xNixO19 hexaferrites (0.0 ≤ x ≤ 1.0).

Herein, Ni2+-Cu2+ co-doped barium hexaferrites (BaFe11Cu1-xNixO19, 0.0 ≤ x≤ 1.0 with an interval of 0.25) were successfully synthesized using a co-precipitation method. The formation of a magnetoplumbite structure with the P63/mmc space group was confirmed by Rietveld refinement of the obtained X-ray diffraction patterns. Microstructural investigations revealed grains in the shape of hexagonal plates, while co-doping resulted in a variation in the grain sizes of the prepared samples. X-ray photoelectron spectroscopy was performed to determine the valence state of iron in the prepared hexaferrites. Impedance spectroscopy analysis revealed that dielectric permittivity initially decreased with an increase in the co-dopant content up to x = 0.5 and then increased by two orders of magnitude for x = 1.0. Alternatively, resistive properties showed microstructural resistance values in the range 105-108 Ω, with the highest value obtained for the sample with x = 0.5. Furthermore, magnetic measurements indicated that all the prepared samples exhibited ferrimagnetic behaviour. Saturation magnetization and magnetic anisotropy values were found to be the highest for the sample with x = 1.0, which also had the lowest coercivity among the prepared samples. Herein, the observed variations in the obtained results can be explained by the variations in grain sizes and the Fe2+/Fe3+ ratio associated with the preferential occupation of co-dopants at octahedral sites. Based on our findings, the BaFe11Ni1O19 (x = 1.0) composition appears to be the most promising choice as a microwave absorption material among the prepared samples owing to the coexistence of high dielectric permittivity (>103 at 107 Hz) and saturation magnetization (73 emu g-1).

Разработка перфорированного элемента рабочего органа глубокорыхлителя: топологическая оптимизация

The development or modernization of tillage machinery aims to increase its service life and efficiency and reduce the negative impact on the soil. In order to increase the efficiency of agricultural machines, the author attempted to optimize the working element of a subsoler - its plate - through topological and parametric modeling. The subsoiler plate with the mass of 1.925 kg with maximum stresses 176.8 MPa was used as a base model. The author determined the plate zones having the least influence on the stiffness and strength of the implement structure. When designing the modernized plate, the following parameters were taken into account: safety factor on the ultimate strength - 1.5 to 2; maximum mass reduction - less than 50%, minimum reduction - more than 10%. The plate is manufactured by laser cutting from 09G2S or 30XGSA steel. The manufacturing process, strength and wear characteristics, and cost were considered to be not lower than the base variant. The algorithm developed in the SysML system modeling language helped systematize the process and establish functional and non-functional requirements and limitations. Using Autodesk Fusion 360 automatic design system, the author developed the rational geometric shape of the soil cultivation plate of the subsoiler with a mass of 1.585 kg and a maximum stresses of 169.5 MPa according to this algorithm. Topological optimization resulted in a 17.67% reduction in the part’s weight at the second iteration while maintaining strength and wear resistance characteristics. By determining the thickness of the element, the author established compliance with the safety factor requirement. Samples of subsoiler plates with thickness of 16 mm were made of 09G2S steel. To confirm the calculated strength characteristics it is necessary to carry out laboratory and field tests of the prototype of the lightweight design.

Study pertaining to leak simulations in electrical leak location dipole testing. A better understanding of dipole testing calibration using various plate sizes and shapes

According to standard ASTM D7007 for geoelectrical leak location (ELL) surveys on earth materials, a hole simulation or calibration must be performed before starting the actual survey. The standard also states that a 1/4 in diameter metal plate must be detectable based on specific signal strengths, if not, the survey cannot be considered completed by the ASTM standard and must be conducted on a 1 m x 1 m grid. Most ELL companies only perform the 1/4 inch test to see if the surveying speed will be fast or slow. The better the signal, the larger the grid, the faster the survey. Usually, leak location practitioners will then proceed to the leak location either way. The number of projects that fail the 1/4 inch test is quite important, so how do we push things further to ensure the best efficiency on site? What information is necessary to understand how the site responds to the test and what can we do to improve the quality of the survey? Here we will compare data gathered within 11 years with various calibration plate sizes and will explain the effects of field specific parameters, such as the simulation’s position, moisture, thickness, cover material homogeneity, and the most important factor of all: peripherical electrical isolation.

Study on roll shape control characteristics of electromagnetic control sleeve support roll

The paper proposed a new type of electromagnetic control support roll to obtain a better ability of controlling the plate shape. According to the principle of induction heating, the bulge shape of the support roll and the contact pressure between the rolls are changed to control the crown of the work roll. To analyze the shape control characteristics of the electromagnetic control sleeve support roll, the roll system model of the four-high mill was established and the no-load bulging experiment was carried out. The simulation results show that under different roll sleeve thickness, current frequency and current intensity, the bulge amount of support roll, contact pressure between rolls and work roll crown increase with heating time, but the growth rate gradually decreases to zero. The bulge of the support roll, the contact pressure between the rolls, the crown of the work roll change quasi-linearly with the current frequency and parabolically with the current intensity. The bulging amount of the support roll and contact pressure decrease with the increase of the thickness of the roll sleeve, and the crown of the work roll increases first and then decreases. This paper verifies the feasibility of adjusting the shape of roll gap by electromagnetic control sleeve support roll, which provides a basis for multi-zone joint control.

Effect of Post-Weld Treatment on the Microstructure and Mechanical Properties of Austempered FeNiCr Steel Welded Joint

This study investigated isothermally treated FeNiCr structural steel welded joints. The base metal contains various phases which are dominated by a mixture of bainite and martensite. Joining this steel can be challenging since it has high carbon equivalent values and high hardness. Shielded metal arc welding (SMAW) with austenitic stainless-steel electrodes is used to avoid cold cracking. After the welding process, the samples were subjected to three various post-weld temperatures: 425°C, 475°C, and 525°C. From the tensile test results, the tensile strength of welded joint shows an increase as the temperatures increase. The highest value is reached for a joint sample which treated at 525°C, with a tensile strength of 680 MPa. Conversely, the highest elongation is obtained by the 425°C post-treated sample, which is 14%. The microstructure in the weld metal (WM) area shows a formation of δ-ferrite, whereas the HAZ and BM areas show the presence of bainite and martensite tempered phases with various plate densities, plate size, and plate shapes depending on its post-treatment temperatures, which then affect the value of the hardness.

Optimized solar food dryer with varied air heater designs

The use of solar energy for drying is considered one of the most environmentally friendly ways to reduce dependence on fossil fuels. The purpose of this experimental study is to determine how absorption plate design affects the evaporation rate of a solar food dryer in Baghdad, Iraq. Tests were performed on four different absorbent panel models. This dryer design consists of a section for heating solar air and one for preserving food. There is insulation at the back of the dining cabinet, which is made of wood. As food samples, orange slices were selected. Except for the absorb plate design, all four models have identical measurements. Matte black aluminum absorbent plate is featured on the Model-1. Both Models 2 and 3 have perforated cylindrical fins arranged uniformly and vertically in Model 2 and horizontally in Model 3. Model 4 uses horizontal fins and an absorber plate coated with 15 % silicon content. A fruit cabinet holds sliced fruit in five movable mesh trays. According to experimental results, the shape of the absorbent plate directly affects the temperature of the outlet air, which in turn affects the rate at which water is evaporated from fruit slices and the overall drying process. Model-1 solar air heaters could be improved by approximately 17 % by coating them with 15 % silicon. The efficiency of Models 2, 3, and 4 is increased by 20 %, 40 %, and 65 % by adding fins and tint over Model 1. Models 1, 2, 3, and 4 had moisture contents of 28 %, 25 %, 20 %, and 18 %, respectively, at 15 p.m. A solar dryer has been demonstrated to be suitable for successfully drying fruits and vegetables in Iraq's atmosphere through practical experiments.

Boosting storage collector efficiency with new corrugated absorbers: A numerical simulation approach

This paper presents a numerical investigation of the performance of a rectangular storage solar collector with three different absorber plate shapes: smooth, parabolic, and triangular. The research employs three-dimensional, unsteady modeling using COMSOL software version 5.5 to simulate a solar storage collector system in Kufa-Najaf's climatic conditions. Two days in November and July were selected to evaluate the system's performance under various atmospheric conditions. The results showed that the highest water temperature for a no-load condition was 36.2 °C in November and 51.7 °C in July. For a triangular corrugation absorber storage collector under load, the largest temperature difference between the outflow and inflow temperatures was 14.9 °C at 1 p.m. and 11.9 °C at sunset in November, while the maximum temperature difference was 13.4 °C at 4 p.m. in July. The study also found that the total efficiency of the triangular corrugation absorber storage collector was higher than that of the other designs, and generally, the total efficiency under no-load conditions was lower than the load. The present work offers a novel solar storage collector configuration with a parabolic or triangular roughened integrated plate absorber, which enhances heat transfer, promoting energy efficiency and improving outlet water temperature.

Study on damage and cracking of Mg-Gd-Y-Ag-Zr alloys during rolling based on experimental and finite element method

Edge cracking, a common issue encountered during the rolling of magnesium alloys, holds substantial importance in determining the success of subsequent finishing processes. It serves as a pivotal parameter for evaluating the formability of rolled plates. In this particular investigation, researchers concentrated on understanding the behavior of edge cracks within the solid solution magnesium alloy designated as Mg-10Gd-3Y-2Ag-0.4Zr (expressed in weight percentage as GWQ1032K). To support this analysis, one delved into the thermal rheological characteristics of the magnesium alloy and established a mathematical relationship connecting rheological stress, strain rate, and temperature. This served as the foundation for a constitutive model tailored to the alloy. Furthermore, practical rolling experiments were conducted to examine how reductions in thickness influenced the morphology of edge cracks in rolled plates. The study also explored shifts in stress–strain behavior and microstructural changes during the deformation process. The results highlighted the substantial impact of compression levels on the magnesium alloy’s anisotropic behavior, subsequently influencing the shape of the resultant plate and the stress–strain characteristics observed during deformation. Significantly, as the rolling reduction increased, a notable increase in heat generation due to the plastic deformation of the magnesium alloy plate was observed. This heightened heat played a key role in dynamic recrystallizationand and facilitating the formation of the brittle Mg5(RE, Ag) phase. Consequently, minimizing the generation of this brittle phase emerged as a critical factor in effectively managing and controlling edge cracks in the rolling process.

Fundamental mode shape-based damage detection in arbitrary shaped plates using a hybrid of contourlet transform and Delaunay triangulation

The past studies have been focused on the field of the damage detection of rectangular plate structures. A major limitation of these studies is that the proposed methods can’t be used for arbitrary shaped plate structures. The main aim of this study is to present a new methodology based on a hybrid of the contourlet transform and the Delaunay triangular for the damage detection in arbitrary shaped plate structures. In the proposed method, the fundamental mode shape of arbitrary shaped plate is first simulated as a 2-D spatially-distributed signal. To achieve this purpose, the intact and damaged plates are separately inserted into a virtual rectangular, and the responses of the fundamental mode shape for the virtual rectangular plates are exploited by the Delaunay triangular as a most popular interpolation method. Then, the contourlet transform is applied to the mode shapes of intact and damaged plates. Finally, the location of damages is identified by a damage index which is obtained using the coefficients of the contourlet transform. The efficiency of the proposed method are investigated for several plate structures with different shapes and an experimental study. Numerical and experimental results show that the proposed method is capable of identifying the location of damages in rectangular and arbitrary shaped plate structures. It also appears that this method can reveal the location of one or multi-damages, and the main shape of actual plates.

Isolated disclination in an orthotropic von Kármán elastic plate

We investigate geometry and mechanics of the buckled orthotropic von Kármán elastic plate, with free boundary condition, in the presence of an isolated positive, or negative, disclination. The buckled shape of an isotropic elastic plate is cone-like for a positive disclination and saddle-like for a negative disclination. In either case, with increasing orthotropy, the shape of the buckled plate becomes more tent-like. The Gaussian curvature accordingly spreads along the ridge of the tent. The stress fields too remain focused in the neighbourhood of the defect point and the ridge, indicating that most of the stretching energy is accommodated in these singular regions.

Parametrical analysis of the strength of the nozzle of a solid fuel rocketer

The paper presents an approach to solving the problem of designing a solid propellant rocket engine nozzle using a design feature in the form of a carbon fiber insert. The design task is to select the optimal parameters of the plate thickness (plate shape) that provide the necessary strength and stability of the structure with a minimum weight. During the design process, a parametric analysis of a carbon fiber insert in the solid propellant rocket nozzle was carried out. By varying the thickness of the plate, an optimal design scheme is found that meets the given safety and stability factors. Parametric analysis of an insert plate made of CM includes modeling of the main weight and strength parameters: determination of the stress-strain state of the structure, values of natural frequencies, determination of the buckling margin, determination of the mass of the solid propellant rocket motor nozzle. Analysis of the bearing capacity of the solid propellant rocket motor nozzle with an insert plate made of CM was carried out using the finite element method using the SolidWorks Simulation software package. During the parametric analysis, two variants of the solid propellant rocket engine nozzle with and without an insert plate were considered. According to the results of the parametric analysis of the solid propellant rocket nozzle, its geometric dimensions were determined and the mass of the structure was minimized.

Self-weight and thermal bifurcation analysis of functionally graded vertical annular plates

The present paper thoroughly investigates the influence of structural weight on the thermal buckling of standing circular and annular plates. The structure is composed of symmetrically functionally graded materials (FGM) in terms of its thickness. The first-order theory of shear deformation along with nonlinear strain–displacement equations has been employed to derive the governing equations of the FG plate. First, the asymmetric pre-buckling path of the structure under the influence of weight and heat is calculated by a semi-analytical method. The plate's stability relations are extracted using the adjacent equilibrium criterion and virtual work principle. Then, the stability equations are analyzed by the 2D generalized differential quadrature (GDQ) method. Parametric results are presented based on the analysis of the FGM power-law index, geometric ratios, and edge constraints on the buckling of the vertical plate. The study reveals the critical power-law index and thickness at which the structure becomes unstable, shedding light on the previously neglected calculation of weight-induced buckling in vertical structures. Also, the effect of weight on the buckling mode shapes of heavy plates and disturbing its symmetry is demonstrated. Additionally, this study presents the first investigation into the effect of weight on the thermal stability of annular FG plates.

Replantation of lamina spinous process ligament complex and miniature titanium plate shaping internal fixation in the treatment of tumors in the spinal canal

ObjectivePurpose This study aims to explore the clinical efficacy of laminospinous process ligament complex reimplantation combined with mini-titanium plate fixation in the treatment of thoracolumbar intraspinal tumors.MethodsA retrospective analysis was performed on 43 cases of intraspinal tumors treated with thoracolumbar intraspinal tumor resection from August 2018 to March 2021, and 27 cases underwent laminospinous process ligament complex reimplantation combined with micro titanium plate shaping. Fixation (laminar replantation group), and 16 patients underwent laminectomy combined with pedicle screw internal fixation (laminectomy group). The operation time, blood loss, drainage tube removal time, cerebrospinal fluid leakage, spinal instability, and the incidence of secondary spinal stenosis were compared between the two groups. The pain VAS score, ODI score, and modified Macnab at the last follow-up were compared between the two groups. And the laminar fusion rate of the laminoplasty group was measured.ResultsBoth groups successfully completed the surgery and obtained complete follow-up. The incidence of cerebrospinal fluid leakage and secondary spinal canal stenosis in the laminectomy group was lower than that in the laminectomy group, and the difference was statistically significant (P < 0.05). There was no statistically significant difference in the incidence of spinal instability between the two groups (P > 0.05). The operation time and intraoperative blood loss in the laminectomy group were less than those in the laminectomy group, and the drainage tube removal time was earlier than that in the laminectomy group. The difference was statistically significant (P < 0.05). At the final follow-up, there was no statistically significant difference in the pain VAS score, ODI score, and modified Macnab between the two groups (P > 0.05), but they were all significantly improved compared with preoperative ones. Fusion evaluation was conducted on the laminoplasty group. Two years after surgery, the fusion rate was 97.56% (40/41).ConclusionsThe application of laminospinous process ligament complex reimplantation combined with mini titanium plate fixation during thoracolumbar intraspinal tumor resection can effectively reconstruct the spinal canal and posterior column structure, reduce the incidence of cerebrospinal fluid leakage and secondary spinal stenosis. The laminar fusion rate is high.

Experimental and Numerical Study on the Perforation Behavior of an Aluminum 6061-T6 Cylindrical Shell.

The modified Johnson-Cook (MJC) material model is widely used in simulation under high-velocity impact. There was a need to estimate a strain rate parameter for the application to the impact analysis, where the method typically used is the Split Hopkinson bar. However, this method had a limit to the experiment of strain rate. This study proposed to estimate the strain rate parameter of the MJC model based on the impact energy and obtained a parameter. The proposed method of strain rate parameter calculation uses strain parameters to estimate from the drop weight impact and high-velocity impact experiments. Then, the ballistic experiment and analysis were carried out with the target of the plate and cylindrical shape. These analysis results were then compared with those obtained from the experiment. The penetration velocities of plates could be predicted with an error of a maximum of approximately 3.7%. The penetration shape of the cylindrical target has a similar result shape according to impact velocity and had an error of approximately 6%.

Simultaneous interferometric profilometry of surface and thickness of transparent plate using wavelength-modulation

Wavelength-modulation interferometers have been widely used to measure the geometric characteristics of transparent plates. However, several errors can be generated by multiple reflections of the laser beams and environmental uncertainties when the wavelength is modulated. In this research, two novel phase-calculation formulas with the same number of interference fringes (15) are proposed to measure the geometric characteristics of a transparent plate. First, a 15s-sample phase-calculation formula for measuring the surface shape of a transparent wedge plate was developed using a system of linear equations. Second, a 15t-sample phase-calculation formula for measuring the optical thickness irregularity of transparent parallel plate was developed by using the characteristic-polynomial theory. The two 15-sample formulas were visualized in the frequency domain and complex plane to confirm the properties of their error-compensation ability. Furthermore, the two formulas were compared with conventional phase-calculation formulas through the numerical analysis. Finally, the surface profile of the wedge plate and optical thickness irregularity of the parallel plate were measured via the two proposed formulas using wavelength-modulation Fizeau interferometer. The standard deviations of 15s-sample formula and the 15t-sample formula were confirmed as 4.3616 nm and 1.2875 nm, respectively. Using these formulas to measure the geometric properties of transparent plate on nanoscale can contribute to the production of high-performance semiconductor devices.

Defensive armament of the Hunnu

The article analyzes the findings of protective equipment made in the archaeological monuments of the Hunnu culture on the territory of Transbaikalia and Mongolia. The description of the main features of horn and iron plates is given, their images are shown. The origin of various elements of armor plating and the period of their existence are considered. Reconstructions of the armours and helmets of the Hunnu have been created with the involvement of fully preserved analogues. The Hunnic warriors used lamellar and scaly cuirass, poncho, and robe armor, as well as lamellar helmets with a closed dome and an open top. The leading role of the Hunnu in the development of iron armor in Central Asia is noted. The appearance of new details of lamellar armor with an original system of six holes and a plate shape borrowed from scaly armor was revealed in the Hunnu. These plates were borrowed by other nomads and the Chinese. It is concluded that the level of development of defensive means allowed the Hunnu to form independent units of armored cavalry. More complete types of armour and helmets, including those of imported origin, were probably owned by commanders (representatives of the nobility). Ordinary warriors used armor of a lightweight design, where in addition to iron, less resistant materials (horn, leather, wood) were also used. Despite the fact that the Hunnu armored cavalry did not yet have sufficient penetrating power in the confrontation with the Chinese infantry, their experience in the development of defensive weapons proved useful for the subsequent evolution of armor among the Nomads.