Plate Material Research Articles

Analysis of electromagnetic force characteristics and wheelbase design of Maglev car based on double permanent magnet electrodynamic wheels

With the advantage of “suspension-drive” integration, the Maglev car has broad application prospects in fields, such as Maglev highways. Currently, a laboratory-scale Maglev car prototype has been built by one of the groups of Southwest Jiaotong University equipped with four permanent magnet electrodynamic wheels. A full-scale Maglev car is planned for design. The distance between the front and rear electrodynamic wheels (EDWs) of a Maglev car will directly affect the safety of the entire car system operation; therefore, it is necessary to explore the wheelbase design. This paper first analyzes the relationship between the electromagnetic force of double EDWs (DEDWs) and the wheelbase under the size of a scaled prototype through 3D simulation and verifies the effectiveness of the simulation model through experiments. Furthermore, the electromagnetic force characteristics of full-scale DEDWs were explored through finite element simulation methods. Finally, we provide the wheelbase design standards for the Maglev car of any size. The findings indicate that the electromagnetic force of DEDWs first rapidly decreases and then stabilizes with increasing wheelbase. The ratio of the inner and outer radius of the DEDWs, and the material and thickness of the conductor plate do not affect the critical value of the wheelbase, while the rotation speed and air gap of DEDWs are the parameters affecting the design of the wheelbase. This article provides a new idea for the wheelbase design of the Maglev car, which is expected to provide some reference for the structural design and parameter optimization of multi-EDW devices.

Impact of hot rolling, Zn and Sn on the mechanical and corrosion characteristics of Mg-Zn-Ca alloys

In this study, it was aimed to develop a biodegradable metallic plate that is an alternative to bioinert metal plates. The main advantage of using biodegradable materials for implants is that they can be gradually replaced with the patient's own tissue, which reduces the need for additional surgeries to remove the implant after it has served its purpose. Magnesium and its alloys can provide biocompatibility as orthopedic implant materials. Mg-Zn-Ca and Mg-Zn-Ca-Sn alloys were prepared using the gravity die casting method. Zn (1.0 wt% and 2.0 wt%) and Sn (0.0 wt%, 0.5 wt% and 1.0 wt%) ratios were used as variables, and the Ca ratio (0.3 wt%) was kept constant in all alloys. After homogenization heat treatment, alloys were hot rolled. Hot rolling resulted in grain refinement, much higher yield and tensile strength, and hardness at the expense of the lower strain. However, hot rolling had a detrimental impact on the corrosion resistance of the alloys. Among the alloys, ZX20-h alloy showed the highest yield and tensile strength before and after corrosion tests. The lowest corrosion rate was measured in ZXT200 alloy as 5.1 mm∙year‒1 after 10 day of immersion. Although ZX20-h alloy has a higher corrosion rate (13.56 mm∙year‒1) than ZXT200 alloy, it can be improved further to be used as biodegradable bone support plate material.

Conjugate heat transfer performance of a ceramic matrix composite plate considering the influences of the mesoscopic properties of yarns

Ceramic matrix composites (CMCs), as a type of material with low density and excellent temperature resistance, are highly conducive to the lightweight and efficient development of future aerospace engines. It is essential to investigate the anisotropic thermal properties of CMCs when applying them to high-temperature components of aerospace engines. This study examined three types of film holes formed in different components of CMCs and compared the overall cooling effectiveness. The influence of the blowing ratio on the overall cooling effectiveness of composite material plates was investigated. The results showed that Type I exhibited better overall cooling effectiveness distribution than Types II and III. With the increase in blowing ratio, the overall cooling effectiveness of the plate was improved. The overall cooling effectiveness at M = 2.0 was 19.67 %, 16.72 %, and 12.1 % higher than those at M = 0.5, 1.0, and 1.5, respectively. The study also investigated the influence of the principal thermal conductivity and volume fraction of yarn on overall cooling effectiveness. An increase in the principal thermal conductivity resulted in an initial deterioration followed by improvement in the cooling effect in the upstream region, while increasing the yarn volume fraction enhanced the cooling effect of the plate.

Finite element structural analysis of simply supported solid and stiffened plates: A comparative study

A structure’s form and shape influence how it behaves when loaded. This was achieved by contrasting the stiffened plate’s performance with that of a solid plate made of the same material and volume. The results have demonstrated that bending stress in stiffened plates is decreased when a solid plate of the same material and volume is transformed into a stiffened plate. Because stiffened plates have a higher strength to weight ratio than solid plates, this supports the recommendation of stiffened plates for a variety of technical applications. In order to determine the impact of stiffener orientation on bending stress reduction in stiffened plates, additional investigations were carried out on a number of plates. An investigation was carried out to determine the ideal stiffener angle in a stiffened plate that could offer the least amount of stress. The current work offers insightful information about particular stiffened plate design characteristics that can be used in a variety of engineering contexts.

Vibration Characteristic Analysis of Sandwich Composite Plate Reinforced by Functionally Graded Carbon Nanotube-Reinforced Composite on Winkler/Pasternak Foundation

This paper presents numerical investigations into the free vibration properties of a sandwich composite plate with two fiber-reinforced plastic (FRP) face sheets and a functionally graded carbon nanotube-reinforced composite (FG-CNTRC) core made of functionally graded carbon nanotube-reinforced composite resting on Winkler/Pasternak elastic foundation. The material properties of the FG-CNTRC core are gradient change along the thickness direction with four distinct carbon nanotubes reinforcement distribution patterns. The Hamilton energy concept is used to develop the equations of motion, which are based on the high-order shear deformation theory (HSDT). The Navier method is then used to obtain the free vibration solutions. By contrasting the acquired results with those using finite elements and with the previous literature, the accuracy of the present approach is confirmed. Moreover, the effects of the modulus of elasticity, the carbon nanotube (CNT) volume fractions, the CNT distribution patterns, the gradient index p, the geometric parameters and the dimensionless natural frequencies’ elastic basis characteristics are examined. The results show that the FG-CNTRC sandwich composite plate has higher dimensionless frequencies than the functionally graded material (FGM) plate or sandwich plate. And the volume fraction of carbon nanotubes and other geometric factors significantly affect the dimensionless frequency of the sandwich composite plate.

Advanced Dynamic Vibration Control Algorithms of Materials Terfenol-D Si3N4 and SUS304 Plates/Cylindrical Shells with Velocity Feedback Control Law

A numerical, generalized differential quadrature (GDQ) method is presented on applied heat vibration for a thick-thickness magnetostrictive functionally graded material (FGM) plate coupled with a cylindrical shell. A nonlinear c1 term in the z axis direction of a third-order shear deformation theory (TSDT) displacement model is applied into an advanced shear factor and equation of motions, respectively. The equilibrium partial differential equation used for the thick-thickness magnetostrictive FGM layer plate coupled with the cylindrical shell under thermal and magnetostrictive loads can be implemented into the dynamic GDQ discrete equations. Parametric effects including nonlinear term coefficient of TSDT displacement field, advanced nonlinear varied shear coefficient, environment temperature, index of FGM power law and control gain on displacement, and stress of the thick magnetostrictive FGM plate coupled with cylindrical shell are studied. The vibrations of displacement and stress can be controlled by the control gain algorithms in velocity feedback control law.

Artificial immune system for fault detection and localization in a composite material plate with temperature variation

Artificial immune system for fault detection and localization in a composite material plate with temperature variation

Free vibration and stability analyses of functionally graded plates resting on elastic foundations based on 2D and quasi-3D shear deformation theories using the finite strip method

This paper explores the elastic buckling and free vibration behavior of thick functionally graded material (FGM) plates placed on elastic foundations, using two-dimensional (2D) and quasi-three-dimensional (quasi-3D) shear deformation theories. The material properties of the FGM plates are assumed to vary continuously through the thickness based on a power-law distribution. By minimizing the total potential energy and solving the associated eigenvalue problem, the classical finite strip method is applied to determine the critical buckling loads and natural frequencies of the FGM plates. A key novelty of this work lies in the development of a quasi-3D shear deformation theory, which incorporates thickness stretching effects, providing a more accurate distribution of transverse shear strains across the plate thickness. Additionally, the FSM is utilized to efficiently discretize the in-plane geometry, offering a computationally cost-effective solution for analyzing free vibration and mechanical buckling characteristics. The elastic foundation is modeled using Winkler and two-parameter Pasternak models. The complexity of the governing equations is reduced by decomposing the transverse displacement into bending, shear, and thickness stretching components. Numerical results for FGM plates with various boundary conditions are validated by comparing them with analytical solutions from existing literature. Additionally, the effects of parameters such as plate thickness-to-length ratio, length-to-width ratio, boundary conditions, and the power-law index are analyzed and discussed.

Optimization of Spot Weld Joining Parameters for Dissimilar Plate Materials through Finite Element Model Updating and Response Surface Methodology

The utilization of dissimilar materials in manufacturing processes, especially in the automotive and aerospace industries, offers substantial benefits such as weight reduction, improved fuel efficiency, and enhanced mechanical properties. However, the optimization of spot welds for these dissimilar materials presents significant challenges due to their diverse physical and chemical properties. This research seeks to optimize the input properties of finite element models (FEM) for spot welding dissimilar plates by utilizing model updating and response surface methodology (RSM). These techniques refine the computational models to more accurately reflect experimental data. Correlation techniques were used to compare Experimental Modal Analysis (EMA) and Finite Element Analysis (FEA), revealing that CWELD has a 1.21% higher correlation compared to CBAR and CBEAM. Despite this, CWELD was chosen for the updating process due to its similarity with the actual joining structure. Subsequent Finite Element Model Updating(FEMU) effectively reduced the error in natural frequency prediction from 6.87% to 4.04%. Additionally, the RSM approach successfully optimized the structural design variables, achieving a desirability rate of 0.972 and showing a significant reduction in percentage error to 5.02% from 6.87%. This study offers valuable insights into the effective enhancement of dynamic properties for dissimilar plate structures, highlighting the importance of both optimization techniques in achieving superior accuracy in structural analysis and design.

Application of big roll and heavy reduction in continuous casting of thick slabs

ABSTRACT Porosity and segregation are common internal defects in thick slabs, which negatively affect the flaw detection qualification rate and mechanical properties of heavy plate materials. This study presents a novel big roll and heavy reduction (BRHR) technology to mitigate these internal defects. The Q345 slab with a thickness of 400 mm and a width of 2400 mm was selected as the specific research object. The cooling strategy was investigated to optimise the solidification front during the BRHR process. Achieving uniform solidification within the slab width significantly reduced porosity during the BRHR process. As the BRHR amount increased from 0 to 20 mm, porosity spots in the center of the thick slab significantly decreased. Additionally, carbon segregation decreased in slabs with BRHR amounts of 10 and 20 mm compared with 0 mm BRHR slabs. Statistical measurements revealed that as the BRHR amount increased from 0 to 20 mm, the ratio of porosity spot area decreased from 0.244% to 0.014%, while the maximum carbon segregation degree decreased from 1.17 to 1.09. Optimal control of uniform solidification across width direction and the total BRHR amount contributed to improve solidification porosity and segregation.

Optimizing the corrosion resistance of additive manufacturing TC4 titanium alloy in proton exchange membrane water electrolysis anodic environment

Titanium alloys are commonly used as the bipolar plate material in proton exchange membrane water electrolysis (PEMWE). However, traditional machining methods are difficult to process titanium alloy parts, which further increases the cost of bipolar plates. The wire-arc directed energy deposition (WA-DED) additive manufacturing (AM) technology is low cost and high utilization of material. However, the undesirable microstructure always restricts the performance improvement. In this work, the electrochemical corrosion and passive characteristics of wrought TC4 and WA-DED AM TC4 alloys in the simulated PEMWE anode environment were investigated. The microstructure of AM TC4 alloy was optimized and the corrosion resistance was enhanced by heat treatment. The results indicate that the corrosion resistance of AM TC4 alloy is better than wrought TC4 alloy, and appropriate heat treatment can further improve the stability of passive film. Compared to wrought TC4, Ti −β phase fraction of AM TC4 decreased from 9.6 % to 1.3 %, and the heat treatment further reduced Ti −β phase fraction of AM TC4-850 and AM TC4-1050 alloys to 0.8 % and 0.1 %. The passive film thickness of wrought TC4, AM TC4, AM TC4-850, and AM TC4-1050 alloys calculated with the Power-Law model were 0.5 nm, 1.76 nm, 1.94 nm, and 2.02 nm, respectively. After heat treatment of 1050 °C, AM TC4-1050 alloy exhibited the best corrosion resistance, showing the lowest corrosion current density of 54 μA/cm2 and the lowest passive current density of 19.5 μA/cm2. Moreover, Ti oxide contributed most to the composition of passive film. In AM TC4-1050 alloy, the percentage of Ti oxides was 80.9 %, showing the best corrosion resistance.

Design and study of a novel rotary high-impact test device

Abstract Impact testing is an important means of evaluating an object’s ability to withstand impacts at specific peak accelerations. Currently, commonly used high-g impact testing devices, such as the Mach hammer and air cannon test devices, generally provide overloads ranging from 10, 000g to 30, 000 g, with a maximum of 50, 000 g. To meet the demand for high-overload impact collisions, this paper designs and studies a high-g long pulse width rotary impact test device with a detachable impact head. A finite element simulation model of the impact process was established by using finite element analysis software, and the dynamic response of the device was studied by changing the initial rotation speed and the target plate material. The results show that the overload of this rotary impact test device can reach more than 70, 000 g, and increasing the speed and hardness of the target plate material can improve the overload magnitude. This device and research method can provide theoretical support for high-overload impact testing.

Preparation and Performance Study of PEK‐C‐OH/MWCNT‐COOH/Graphite Composite Bipolar Plates for PEMFCs With Improved Interface Properties

ABSTRACTBipolar plates are an essential part of proton exchange membrane fuel cells, and due to the specificity of their functions, various properties are required. In this study, a composite bipolar plate with a “sandwich” structure was prepared to solve the problems of graphite/resin composite bipolar plate, which is challenging in balancing the electrical conductivity and mechanical properties, and the interface is not tightly bonded. Through the bidirectional modification between graphite‐carbon/nanotubes and resin, the graphite phase and resin phase are connected by chemical bonding, which enhances the direct interfacial bonding performance, effectively broadens the conductive pathway, and improves the mechanical properties. The prepared composite bipolar plate showed a conductivity of 244.01 S/cm, a hydrophobicity angle of 121.4°, a flexural strength of 53.38 MPa, a corrosion current density of 0.76 μA/cm2, and a corrosion voltage density of 0.354 V. The composite bipolar plate showed good performance, and it is expected to be one of the candidates for future graphite/resin composite bipolar plate materials.

Influence of Hall Current and Acoustic Pressure on a Thermoelastic Plate in a Two-Temperature Model Undergoing Ramp-Type Heating

This study proposes a novel thermoelastic model that incorporates Hall current effects, acoustic pressure, and ramp-type heating within the framework of the two-temperature (2T) linear theory. Essentially, this model aims to advance the overarching theory of thermoelasticity enabling both thermal-acoustic and mechanical analyses of elastic plate material under a strong external magnetic field to produce a Hall current. Normal mode (harmonic wave) approximation solved specific boundary value problems within the applied theory of magneto-thermal acoustic systems. Constitutive equations were formulated, yielding two distinct temperatures: conductive and thermodynamics, acoustic pressure displacements, and mechanical stress distribution. The study examines the thermoacoustic interactions and resulting stresses within the material under both external mechanical loads and magnetic fields subjected to ramp-type heating. Notably, the study delves into the effects of Hall current, relaxation times, and ramp-type heating parameters, elucidating their significance within the given context. The wave propagation of physical quantities is represented graphically and discussed and analyzed theoretically.

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

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

Evaluation of Hair Changes and Damage According to Hair Iron Heating Plate Material

This study investigates the effects of ceramic and polymer heating plates on the surface and structure of hair. To evaluate the degree of hair damage caused by the iron and polymer heating plate materials, hair moisture content and the degree of hair fading were measured using Thermo Gravimetric Analysis (TGA) and a colorimeter, respectively. Additionally, a Scanning Electron Microscope (SEM) was used to analyze the change in the microstructure of the hair. As a result, hair treated using a polymer iron contained significantly higher moisture than hair treated using a ceramic iron. The colorimeter analysis showed that ceramic irons caused fading and damage to hair color, whereas polymer irons did not. Lastly, hair treated with a ceramic flat iron had extensive surface scratches and cuticle melting from the SEM analysis, unlike hair treated with a polymer iron, which preserves superior hair shape and cuticle integrity.

Evaluation of the Corrosion Resistance of 904L Composite Plate in a High-Temperature and High-Pressure Gas Field Environment

In order to study the corrosion resistance of 904L composite plate pressure vessels under a high-temperature and high-pressure gas field environment, the pitting corrosion and stress corrosion cracking resistance of a 904L composite plate body and weld material were compared with those of a 2205 composite plate and 825 composite plate, which are used in high-temperature and high-pressure gas field environments. The results showed that the pitting resistance of the 904L composite plate was lower than that of the 825 composite plate and higher than that of a 2205 solid-solution pure material plate and a 2205 composite plate. The corrosion resistance of the 625 welding material is higher than that of the E385 welding material. In the simulation of the corrosion environment of a high-temperature and high-pressure gas field, the corrosion rates of the 904L composite plate body, welding seam, and surfacing welding were all less than 0.025 mm/a, indicating slight corrosion, and the sensitivity coefficient of chloride stress corrosion cracking was less than 25%, indicating low sensitivity. The 904L composite plate met the requirements of corrosion resistance for pressure vessel materials in a high-temperature and high-pressure gas field environment.

Evaluation of stiffness-matched, 3D-printed, NiTi mandibular graft fixation in an ovine model

BackgroundManually bent, standard-of-care, Ti–6Al–4V, mandibular graft fixation devices are associated with a significant post-operative failure rate. These failures require the patient to endure stressful and expensive re-operation. The approach recommended in this report demonstrates the optimization of graft fixation device mechanical properties via “stiffness-matching” by varying the fixation device’s location, shape, and material composition through simulation of the device’s post-operative performance. This provides information during pre-operative planning that may avoid future device failure. Optimized performance may combine translation of all loading into compression of the bone graft with the adjacent bone segments and elimination or minimization of post-healing interruption of normal stress–strain (loading) trajectories.ResultsThis study reports a sheep mandibular graft model where four animals received virtually optimized, experimental nickel–titanium (NiTi) fixation plates fabricated using laser beam powder bed fusion (LPBF) additive manufacturing (AM). The last animal, our control, received a standard-of-care, manually bent, Ti–6Al–4V (aka Ti64) fixation plate. A 17.5-mm mandibular graft healed completely in all four animals receiving the experimental device. Experimental NiTi-implanted sheep experienced mandibular bone healing and restoration. The Ti64 plate, in the control animal, fractured and dislocated shortly after being implanted.ConclusionThe use of stiffness-matched implants, by means of plate material (NiTi) and geometry (porosity) enhanced bone healing and promoted better load transfer to the healed bone when compared to the bulk Ti64 found in the fixation plate that the Control animal received. The design technique and screw orientation and depth planning improved throughout the study leading to more rapid healing. The large animal model reported here provides data useful for a follow-on clinical trial.Graphical

Spatiotemporal evolution of post-seismic deformation caused by large earthquakes around the Pacific and its impact on plate movement

SUMMARY The fully relaxed deformation caused by an earthquake refers to the total deformation of the earth caused by the earthquake, including the coseismic deformation and the total effect of post-seismic stress relaxation in the mantle on crustal deformation. An in-depth investigation into post-seismic and fully relaxed deformation resulting from large earthquakes is conducive to comprehending the feedback effect of earthquakes on plate motion. In this paper, we first calculated theoretically the coseimic, post-seicmic and fully relaxed deformations caused by the Tohoku-Oki Mw9.0 earthquake using the spherical dislocation theory. The post-seismic displacement caused by the great earthquake leads to the continuous convergence of plates on both sides of the seismogenic fault, which will certainly facilitate the downward insertion of the subduction plate. As time goes by the influence range of seismic deformations becomes larger and larger. The Tohoku-Oki Mw9.0 earthquake can produce >5 cm of cumulative post-seismic horizontal displacement at a far place like the East Pacific Rise over 100 millenniums. Then, we built slip models of 375 earthquakes with Mw7.0 and above in the circum-Pacific seismic belt, calculated the cumulative post-seismic deformations of them, and found that significant post-seismic horizontal displacements covered the entire Pacific Ocean. The post-seismic deformation field caused by the 2011 Tohoku-Oki Mw9.0 earthquake, the 2010 Chile Mw8.8 earthquake, the 1964 Prince William Sound Mw9.1 earthquake and the 1960 Chile Mw(9.3–9.4) earthquake determines the overall distribution pattern of the deformation field in the Pacific region. Those large earthquakes around the Pacific make the total Pacific Plate present a tension strain in the northwest–southeast direction. The one at the East Pacific Rise reaches 300–400 nstr, with orientation of principle strain approximately perpendicular to the Rise. This tensile strain is bound to encourage transverse expansion of the mid-ocean ridge. By a logical extension, the post-seismic stress relaxation in the mantle caused by past earthquakes should be an important driving force for the current plate movement, in addition to the classic driving force like negative buoyancy and plate material phase transition. This study proves theoretically that there is a two-way relationship between great earthquakes and plate movement, and the viscous structure of mantle plays a key role in the relationship.

An optical field regulation method for waterjet-guided laser: Reducing taper and improving deep-processing capability

Waterjet-guided laser (WGL) processing technology has the advantages of low thermal damage, no contact stress and ultra-fine processing. However, the energy distribution of the existing technology in the laminar flow water column is still characterized by Gaussian distribution, which leads to taper effect in the processing of thick plate materials and affects the deep-processing capability. To address these shortcomings, a novel waterjet laser-field regulation (WLR) method is proposed in this paper. Optical simulation and coupling experiments confirm the method's ability to modulate the energy within the waterjet into a circular distribution, which solves the problem of low power density near the surface of the waterjet. Waterjet-guided laser cutting experiments were conducted based on the WLR method, and the taper was significantly reduced compared to the conventional WGL. At a power of 12 W, the taper was reduced from 5.85° to 2.28°, a reduction of 61 %. In terms of processing depth, the WLR method cuts slightly lower groove depths with a low number of cuts, but as the number of cuts increases, the groove depth steadily increases and exceeds that of the conventional WGL. At 500 cuts with a laser power of 20 W, the groove depths obtained by the WLR method increased by 115 % compared to that of the conventional WGL. This study has important implications for the processing of thick materials by waterjet-guided laser.