Plate Components Research Articles

Topological atlas of the hypothalamus in adult rhesus monkey

The prosomeric model explains the embryological development of the central nervous system (CNS) shared by all vertebrates as a Bauplan. As a primary event, the early neural plate is patterned by intersecting longitudinal plates and transverse segments, forming a mosaic of progenitor units. The hypothalamus is specified by three prosomeres (hp1, hp2, and the acroterminal domain) of the secondary prosencephalon with corresponding alar and basal plate parts, which develop apart from the diencephalon. Mounting evidence suggests that progenitor units within alar and basal plate parts of hp1 and hp2 give rise to distinct hypothalamic nuclei, which preserve their relative invariant positioning (topology) in the adult brain. Nonetheless, the principles of the prosomeric model have not been applied so far to the hypothalamus of adult primates. We parcellated hypothalamic nuclei in adult rhesus monkeys (Macaca mulatta) using various stains to view architectonic boundaries. We then analyzed the topological relations of hypothalamic nuclei and adjacent hypothalamic landmarks with homology across rodent and primate species to trace the origin of adult hypothalamic nuclei to the alar or basal plate components of hp1 and hp2. We generated a novel atlas of the hypothalamus of the adult rhesus monkey with developmental ontologies for each hypothalamic nucleus. The result is a systematic reinterpretation of the adult hypothalamus whose prosomeric ontology can be used to study relationships between the hypothalamus and other regions of the CNS. Further, our atlas may serve as a tool to predict causal patterns in physiological and pathological pathways involving the hypothalamus.

RESEARCH PROGRESS OF SHEAR WALLS: TYPES AND DESIGN METHODS

Reviews the development of shear walls in terms of their materials and section patterns in the recent decades. Because of the higher strength capacity, better seismic performance and possible architectural layout categories, the shear wall system has been increasingly applied to high-rise buildings and residential structures. Shear walls have experienced a long course of development from reinforced concrete, all steel to steel-concrete compositions. With the continuous innovation of materials and section types, shear walls are gradually developing towards high performance and prefabrication, which conform to the development needs of the residential buildings in China. This paper first focuses on the structural mechanism and design methods of various new steel corrugated plate shear walls and their experimental results under monotonic loads and horizontal cyclic loads. This paper also focuses on the structural mechanism and prefabrication process of concrete-infilled double steel corrugated-plate walls (CDSCWs). The research process, experimental results and design methods for the sectional strength capacity, overall stability, limb panel stability and seismic performance of CDSCWs are elaborated. Some key design formulas in the strength design are given. In addition, this paper introduces the scope and content of the “Technical Specification for Structures with Corrugated Steel Plate Components”, and briefly describes the design methods for special shaped concrete filled steel tubular columns (SSCFSTs) in the CDSCW-SSCFST frame structure system.

Sound Radiation Analysis of Functionally Graded Porous Plates with Arbitrary Boundary Conditions and Resting on Elastic Foundation

In this paper, the sound radiation behaviors of the functionally graded porous (FGP) plate with arbitrary boundary conditions and resting on elastic foundation are studied by means of the modified Fourier series method. It is assumed that a total of three types of porosity distributions are considered in the present study. The material parameters are determined according to the porosity coefficient used to denote the size of pores in the plate. The governing equations of the FGP plate are derived by utilizing the Hamilton’s principle on the basis of the first-order deformation theory (FSDT). Each displacement component of the FGP plate is expanded as the Fourier cosine series combined with auxiliary polynomial functions introduced to enhance the convergence rate of the series expansions. The acoustic response of the FGP plate due to a concentrated harmonic load is calculated by evaluating the Rayleigh integral. Good agreements are attained by comparing the present results with those in available literatures, which show the accuracy and versatility of the developed method in this paper. Finally, the influences of the porosity distribution type, porosity coefficient, boundary condition and elastic foundation on the sound radiation of the FGP plate are analyzed in detail.

Effect of a New Absorber Design on the Performance of PV/T Collector: Numerical Comparative Study

The solar energy applications can be roughly divided into two main groups. A photovoltaic is an energy system that transforms solar energy into electric power and thermal energy system called solar collector that transforms solar energy into thermal energy. The photovoltaics performance affected by the high temperature of it is surface that absorbs the solar irradiance and the efficiency drop due to these higher temperatures. Therefore, the two systems associated with each other in the combined system called PV/T to enhance photovoltaic efficiency. The term PV/T (photovoltaic thermal) refers to a solar collector that uses a photovoltaic cell as an integral component of the absorption plate. The high temperature of solar photovoltaic will be decreased and transmitted to the circulated fluid inside the collector tubes. This system produces electrical and thermal at the same time. The solar collector is the vital part of PV/T. Many absorber designs have been developed in the solar collector to enhance the overall performance of the PV/T system. In the present work, a new photovoltaic thermal collector named serpen-direct is designed. Modeling for the new absorber design has been developed and validated. Numerically, PV/T performance for the serpent-direct design is analyzed and compared with the conventional serpentine design by using MATLAB Simulink. The PV and thermal efficiencies were determined under various parameters condition; mass flow rates range from 0.01 kg/s to 0.1 kg/s and solar irradiance values 700 W/m2 and 900 W/m2. Results indicate that the serpen-direct flow absorber design achieved a better system overall performance than serpentine design under similar operating conditions. The higher electrical and thermal efficiencies were 14.52%, 55%, respectively, for the PV/T serpen-direct absorber design and 14.43 %, 56.1%, correspondingly, for the serpentine absorber design.

Fatigue performance of profiled steel sheeting–concrete bridge decks subjected to vehicular loads

Bridge decks are usually formed from profiled steel–concrete composite slabs, which consist of steel and concrete. Slip occurs at the interface between the concrete and steel, which results in unique mechanical and fatigue properties of the composite slab. The objective of this study is to investigate the mechanical and fatigue performance of profiled steel sheeting–concrete bridge decks subjected to vehicular loads. A new method for calculating the deflection of profiled steel sheeting–concrete composite slabs based on a discontinuous stiffness is proposed, and the deformation and internal force components of composite plates are deduced theoretically. The midspan deflection and end-slip calculated via this method are close to the experimental values. With a focus on the fatigue performance of the bridge deck, this paper discusses the fatigue design method of the composite slab and presents fatigue-check calculations for the Khartoum Al-Halfaia bridge over the Nile. A parameter analysis of the composite slab bridge was performed. The effects of the thickness and section geometry of the profiled steel plate and the strength grade and thickness of the concrete on the fatigue performance were investigated, and corresponding improvement measures were examined. It was found that the thickness and geometry of the section significantly affect the shear-stress amplitude of the plate end interface, while the concrete strength grade has little influence on the fatigue performance of the composite slab.

Flutter and Thermal Buckling Properties and Active Control of Functionally Graded Piezoelectric Material Plate in Supersonic Airflow

This paper is devoted to investigate the flutter and thermal buckling properties of the functionally graded piezoelectric material (FGPM) plate in supersonic airflow, and the active flutter control is carried out under different temperature fields. The piezoelectric material component of the FGPM plate has gradient changes along the thickness, such as piezoelectricity and dielectric coefficients. The supersonic piston theory is used to evaluate the aerodynamic pressure. Based on the first-order shear deformation theory and Hamilton’s principle with the assumed mode method, the equation of motion of the structural system is deduced. The effect of aerodynamic pressure on the frequency and damping ratio of the FGPM plate is analyzed. Moreover, the flutter and thermal buckling properties of the FGPM and pure metal plates are compared to show the superior aerothermoelastic properties of the FGPM plates. The influences of volume fraction exponent and temperature on the flutter and thermal buckling properties of the FGPM plate are also examined in detail. The LQR controller is adopted to achieve active flutter control. The simulation results show that the present control method can largely improve dynamic stability of the FGPM plate in supersonic airflow and high-temperature environment.

Numerical prediction and experimental validation of impact sound radiation by timber joist floors

Timber joist floors are widely applied in residential buildings. The accurate prediction of the sound radiated by timber joist floors is challenging due to the interaction between the impacting mass and the floor, orthotropy of the joist and plate components, the effects of the floor size and boundary conditions, etc. In the present work, state-of-the-art approaches for the prediction of impact forces, structural vibration, and radiated sound power were combined into a prediction method for the sound pressure level in a room due to sound radiation by an impacted timber joist floor. This method was then extensively validated in a case study. The natural frequencies and mode shapes of the decoupled joists and plates were both experimentally determined and computed from finite element models, and a good agreement was found when an orthotropic material model is considered for all components. A considerable variation in material properties between nominally identical parts was also discovered. The accuracy of the floor assembly model was subsequently investigated, also by means of modal testing. It was found that a correct representation of the boundary conditions plays a key role in the accuracy of the predicted floor vibration field. Finally, the radiated sound pressure levels were measured and computed. A satisfactory agreement between measurement and computation was observed. At very low frequencies, the interaction between the floor and room modes can play an important role, and a modal room model is employed instead.

Prediction of mesoscale deformation in milling micro thin wall based on cantilever boundary

The micro channel cold plate is very suitable for the application environment of high heat consumption liquid cooling such as PCB plate and multi-layer components. However, at mesoscale, the titanium alloy micro channel cold plate is micro thin-walled structure of cantilever boundary with weak stiffness, which leads to significant deformation and resultant poor machining accuracy during micro milling. To effectively control and reduce micro thin-walled deformation, a 3D FE cantilever model is established to predict dynamic milling deformation of micro thin wall. The constitutive model of titanium alloy (Ti-6Al-4 V) that includes the strain gradient to consider size effect in micro milling, the edge geometry of milling cutter, the thin-walled microstructure, and micro milling parameters is involved in milling modeling of thin wall. Moreover, a series of micro milling experiments for micro thin wall of titanium alloy at different machining parameters were carried out to investigate the law and mechanism of thin wall deformation in milling micro thin wall subjected to dynamic alternating forces. By comparing numerical and experimental deformation of micro thin wall in micro milling, the accuracy and validity of the prediction model based on cantilever boundary are verified, which provides theoretical support and model basis for the deformation control in milling micro channel cold plate at mesoscale.

Seismic Design of the Box for the Gas Flow-Rate Metering Unit

To study seismic resistance of the box for the metering unit of gas flow-rate required to ignite the flare system we used the calculation methods developed on the basis of the method of finite elements and the software designed to define the mode of deformation and the dynamics of structures for the three-dimensional statement. To construct the simulation model, we took into account all the elements that affect the strength and the efficiency of the real structure during possible earthquakes. Structure elements were simulated using the sets of arbitrary oriented rods and lumped masses with inertia moments and those rods were connected absolutely rigidly with each other and using also elastically damped elements. The rod elements with distributed parameters took into consideration all the types of deformations that occur during the vibrations. The plate components of the structure were simulated using the grids made of the rods taking into consideration the ductility and inertia properties of its elements. Lumped masses in the rod connections were used to take into account the masses of installed equipment, pipelines, etc. The seismic loading was simulated using alternating inertia forces transferred from the ground. The soil ductility was taken into account by the Winkler model. Computations were done for the sand and rock stone ground and for the fine-grained sand. Consideration was given to the seismic forces of a different intensity that are represented by three-component accelerograms. Synthesized and real accelerograms were analyzed. The obtained computation data showed that the structure of the box of the metering unit of gas flow rate is quakeproof and it won’t be destroyed during its operation.

Experimental and Numerical Free Vibration Analysis of Laminated Composite Plates with Arbitrary Cut-Outs

Cut-outs are the integral parts of laminated plate components in a variety of civil, aerospace and marine engineering applications. Cut-outs alter the dynamic behaviour of the structures by reducing mass and stiffness simultaneously. The glass epoxy laminates are fabricated by resin infusion method through vacuum bagging system in the laboratory. The experimental studies are carried out on composite plates with cut-out positioned at different locations in the laminate. A finite element formulation based on the first-order shear deformation theory is developed in the present study using nine noded isoparametric shallow shell elements. The effects of rotary inertial contribution of mass on the natural frequencies are studied in the present paper. The present finite element formulation is validated by comparing the solutions obtained in terms of natural frequencies with the relevant published results and also experimental data. The correlation between experimental and numerical mode shapes is established by using modal assurance criteria.

Experimental and numerical investigation of low-yield-strength (LYS) steel plate shear walls under cyclic loading

Steel plate shear walls (SPSWs) are lateral load resisting systems with a significant energy dissipation potential under cyclic loading. This research performed experimental and numerical investigation of the cyclic behavior of low-yield-strength (LYS) SPSW. Two specimens with 1:3 scale three-story single-bay SPSW with unstiffened infill plates were tested using cyclic loading. The steel plate shear walls had two types of moment-resistant and pinned beam-to-column connections. Also, low-yield-strength (LYS) and high-yield-strength (HYS) steel were used for the infill plates and boundary frames, respectively. The results indicated that the test specimens had good stiffness, high ductility, significant energy dissipation, and stable cyclic behavior. Also, the results revealed that the type of beam-to-column connection affects ductility, strength, and energy dissipation and has a negligible effect on the initial stiffness. In addition, the nonlinear finite element (FE) models were developed to predict the hysteresis behavior of SPSWs. In the FE models, the nonlinear behavior of geometric and materials, large deformations, and initial geometric imperfections were considered. The nonlinear FE models of SPSWs were verified against experimental results. The hysteresis curves, failure modes, and base shear capacity FE models were compared with the experimental results. The numerical investigation showed that the cyclic behavior of the SPSW could be simulated using a simplified FE model. It is demonstrated that rigid and pinned beam-column connection can influence the strength performance and total energy dissipation of an SPSW system and material properties of the infill plate components, especially LYS steel, can further advance the impact of such connection.

A new approach to deformation control of aeronautical monolithic components of aluminum alloy plates based on stress inverse and stress evaluation

In the high-speed machining process of aeronautical monolithic component, the release of residual stresses is a crucial factor of machining deformations with the material removal of 7075 aluminum alloy thick plates. Therefore, the investigation on the evolution mechanism of machining deformation with residual stress release is crucial for machining quality control. It is vital to achieving a high-efficiency and precise machining process. In this work, the bending deformation theory is employed to formalize the mechanical model of machining deformation, which is influenced by the removal of materials. The finite element method is used to calculate the unit deformations by producing the unit stresses in each layer of the aluminum alloy thick plate. The unit force method is established so that the mechanical model of machining deformation can decompose to be multiple of deformation factor with residual stress. Further, by considering the self-equilibrium of residual stresses, the specification model of residual stresses is proposed based on the fact that the machining requirement represents the control limit of machining deformation. By introducing a new unit variable, the sandwich theorem is employed to convert the specification model into the linear homogeneous inequalities. Therefore, the pivot transformation method is suggested to solve the residual stresses in the specification model. Finally, by representing an arbitrary variable as a difference between two non-negative variables, the linear programming method is proposed to judge whether the measured blank initial residual stress is a solution of stress specification. This can evaluate machining deformation within the machining requirement. The active evaluation of residual stresses, which is deduced from the passive analysis of machining deformations by unit force method and pivot transformation, can provide the proper stress specification for the upper of the machining process. Obviously, the stress specification plays a very important role in the bridge between the blank manufacturing and the machining process.

Polya Counting Theory Applied to Combination of Edge Conditions for Generally Shaped Isotropic Plates

Structural behaviors of plate components, such as internal stress, deflection, buckling and dynamic response, are important in the structural design of aerospace, mechanical, civil and other industries. These behaviors are known to be affected not only by plate shapes and material properties but also by edge conditions. Any one of the three classical edge conditions in bending, namely free, simply supported and clamped edges, may be used to model the constraint along an edge of plates. Along the entre boundary with plural edges, there exist a wide variety of combinations in the entire plate boundary, each giving different values of structural responses. For counting the total number of possible combinations, the present paper considers Polya counting theory in combinatorial mathematics. For various plate shapes, formulas are derived for counting exact numbers in combination. In some examples, such combinations are confirmed in the figures by a trial and error approach.

A minimally-intrusive fully 3D separated plate formulation in computational structural mechanics

Most of mechanical systems and complex structures exhibit plate and shell components. Therefore, 2D simulation, based on plate and shell theory, appears as an appealing choice in structural analysis as it allows reducing the computational complexity. Nevertheless, this 2D framework fails for capturing rich physics compromising the usual hypotheses considered when deriving standard plate and shell theories. To circumvent, or at least alleviate this issue, authors proposed in their former works an in-plane–out-of-plane separated representation able to capture rich 3D behaviors while keeping the computational complexity the one of 2D simulations. In the present paper we propose an efficient integration of fully 3D descriptions into existing plate software.

The Optimized Welding Spot Structure Parameters of Corrugated Plate Component Based on Variance Analysis

According to the fourth strength theory, this paper adopted equivalent stress to simulate fatigue life. Firstly, ANSYS was used to simulate equivalent stress in single-row welding, and variance analysis was used to analyze and process the simulation results to obtain the effect law of horizontal spacing and diameter of welding spot on the stress. Then, the equivalent stress of corrugated plate component, which was welded in triangular solder joint arrangement, was analyzed and treated with the method of variance analysis, and the effect law was obtained. In terms of the structure parameters of welding spot, the left and right margin of welding spot in the first row is 10 mm, 7 in number, and the center of the welding spot is 3.5 mm away from the upper boundary; the left and right margin of welding spot in the second row is 91.7 mm, 6 in number, and the center of the welding spot is 4.5 mm away from the upper boundary; both rows have a diameter of 5 mm and a horizontal spacing of 163.3 mm. Moreover, the actual fatigue life of physical test is more than 2.0E7 times, meeting the requirements of the working condition.

A two-stage deep neural network for multi-norm license plate detection and recognition

In this work, we tackle the problem of multi-norm and multilingual license plate (LP) detection and recognition in natural scene images. The system architecture use a pipeline with two deep learning stages. The first network was trained to detect license plates on the full raw image by using the latest state-of-the-art deep learning based detector namely YOLOv2. The second stage is then applied on the cropped image to recognize captured license plate photographs. Two recognition engines are compared in this work: a segmentation-free approach based on a convolutional recurrent neural network where the recognition is carried out over the entire LP image without any prior segmentation and a joint detection/recognition approach that performs the recognition on the plate component level. We also introduced a new large-scale dataset for automatic LP recognition that includes 9.175 fully annotated images. In order to reduce the time and cost of annotation processing, we propose a new semi-automatic annotation procedure of LP images with labeled components bounding box. The proposed system is evaluated using two datasets collected from real road surveillance and parking access control environments. We show that the system using two YOLO stages performs better in the context of multi-norm and multilingual license plate. Additional experiments are conducted on the public AOLP dataset and show that the proposed approach outperforms over other existing state-of-the-art methods.

Structure Parameter Optimization of Welding Spot of Corrugated Plate Component

A simple model is used to determine the research route of corrugated plate component with good fatigue life based on equivalent stress, and the simulation results are proved to be reasonable by physical test. It is found that the equivalent stress of corrugated plate component increases with the increase of horizontal distance between welding points during single-row welding, after the analysis of the simulation results. In all the arrangement forms, the number of welding points arranged in triangle arrangement is large, which has good connection effect on corrugated plate component and good structural stability. Therefore, it is better to connect corrugated plate component in a way of welding in row 3, with a distance of 2 mm from top to bottom, a distance of 10 mm from left and right sides of row 1 and row 3, and a distance of 37.2 mm from left and right sides of row 2. The fatigue life simulation result of corrugated plate component under the structural parameters is 7.89e6 times, and the actual fatigue life of physical test exceeded 3.0e7 times, meeting the working condition requirements.

Numerical modeling and parametric study of an innovative solar oven

A unique design of a double glazed box-type solar oven with flat foldable external reflectors at the top and front and an internal reflector beneath the L-shaped absorber plate is numerically and parametrically studied. The maximum temperatures attained in the absorber cavity of the oven are observed to be in the range of 100–135 °C. A numerical model is formulated to solve the overall energy balance on the absorber plate of the proposed solar oven by incorporating the effects of the top, front, and bottom reflectors for a given set of input parameters. CFD simulations are utilized to predict the unknown buoyancy driven convective heat transfer coefficient from the L-shaped absorber plate to the surrounding glass cover forming an enclosure. Modeling results are found to be in good agreement with the experimental results which leads to the parametric study of the solar oven. The effects of various design parameters on the oven‘s performance such as spacing between glazings, influence of the vertical component of the absorber plate and internal reflector, glazing thickness number of glazings and the effect of absorber plate coatings are also discussed.

Vibration and sound radiation analysis of temperature-dependent porous functionally graded material plates with general boundary conditions

This paper investigates the vibration and sound radiation of porous functionally graded material (FGM) plates with temperature gradient along the thickness. The even and uneven porosity distributions are taken into consideration in the present study. The formulation of the FGM plate is based on the first-order shear deformation theory (FSDT) with the temperature dependence of material properties considered. Each displacement component of the FGM plate is expanded as the Fourier cosine series combined with auxiliary functions in order to satisfy the general boundary conditions. A substantial number of numerical examples concerning the vibration and sound radiation responses of the heated plate are carried out to validate the convergence and accuracy of the proposed method. Finally, the effects of key parameters including the boundary condition, volume fraction index, thermal environment, temperature dependence of material properties and porosity volume fraction on the structural and acoustic responses of the FGM plate are discussed in detail.

The Interfacial Characterization and Performance of Cu/Al-Conductive Heads Processed by Explosion Welding, Cold Pressure Welding, and Solid-Liquid Casting

The Cu/Al composites conductive head is widely used in hydrometallurgy as the core component of cathode plate. Its conductive properties directly affect the power consumption, and the bonding strength and corrosion resistance determine the conductive head service life. The Cu/Al conductive head prepared by explosion welding, cold pressure welding, and solid-liquid casting methods were investigated in this paper. The interface microstructure and compositions were examined by scanning electron microscope and X-ray energy dispersive spectrometry. The bonding strength, interface conductivity, and the corrosion resistance of three types of joints were characterized. The Cu/Al bonding interface produced by explosive welding presented a wavy-like morphology with typical defects and many of brittle compounds. A micro-interlocking effect was caused by the sawtooth structures on the cold pressure welding interface, and there was no typical metallurgical reaction on the interface. The Cu/Al bonding interface prepared by solid-liquid casting consisted mainly of an Al-Cu eutectic microstructure (Al2Cu+Al) and partial white slag inclusion. The thickness of the interface transition layer was about 200–250 µm, with defects such as holes, cracks, and unwelded areas. The conductivity, interfacial bonding strength, and corrosion resistance of the conductive head prepared by explosive welding were superior to the other two.