Strip Model Research Articles

An Analytical Model for Stress and Curvature Prediction of a Strip Leveling Process

An analytical model of a steel strip under alternate bending/reverse bending during a roller leveling process is developed. A combined isotropic/kinematic hardening model is implemented through a combined hardening parameter. A formulation of the change of the effective stress as a function of the change of the effective strain under cyclic loading is combined with the developed analytical model to predict the stress distributions and residual curvature of a steel strip under roller leveling efficiently and accurately. Dissimilar to the commonly used assumption of one contact point between the stripe and the rolls, an effective radius modelling the wrap-around contact characteristics is proposed. An arc contact of the strip around a roll is described by the contact model. An oscillatory behavior of the residual curvature is observed when a range of roll intermesh setting is considered. The contact model added to the analytical model may enhance the accuracy in predicting the oscillatory behavior of the residual curvatures. A range of the roll intermesh setting can be suggested by the developed model to obtain a flat strip after roller leveling.

Bistability and equilibria of creased annular sheets and strips

A creased thin disk is generally bistable since the crease could be pushed through to form a stable cone-like inverted state with an elastic singularity corresponding to the vertex of the conical surface. In a recent study, we found that this bistability could be destroyed by removing the singularity through cutting a hole around the vertex, depending on the size and shape of the hole. Particularly, to maintain the bistability, a circular hole normally cannot exceed approximately 20% of the disk size. This paper extends our recent work and is based on the following observations in tabletop models of creased disks with circular holes: (i) reducing the circumference of the creased disk by removing an annular sector could increase the hole size to be as large as the disk without destroying the bistability, (ii) with a single crease, the circular hole could be as large as the disk without loss of the bistability, and (iii) a family of stable inverted states can be obtained by inverting the disk almost anywhere along the crease. An inextensible strip model is implemented to investigate these phenomena. We formulate a minimal facet of the creased disk as a two-point boundary value problem with the creases modeled as nonlinear hinges, and use numerical continuation to conduct parametric studies. Specifically, we focus on geometric parameters which include an angle deficit that determines the circumference of the disk, the rest crease angle, the number of evenly distributed creases, and an eccentricity that determines the position of the hole on the crease. Our numerical results confirm the qualitative observations in (i)-(iii) and further reveal unexpected results caused by the coupling between these geometric parameters. Our results demonstrate that by varying the geometry of a simply creased disk, surprisingly rich nonlinear behaviors can be obtained, which shed new light on the mechanics and design of origami, kirigami, and morphable structures.

Research on shear performance of corrugated steel plate shear walls with inelastic buckling of infilled plates under lateral loads

The corrugated steel plate shear wall (CoSPSW) system has potential in resisting lateral wind and seismic loads in high-rise buildings. This paper presents a numerical and theoretical investigation of the shear behaviour of CoSPSWs with inelastic buckling mode of the corrugated steel plate (CSP) subjected to lateral loads. The geometry parameters of CoSPSWs with inelastic buckling of infilled plates were derived theoretically. In addition, a series of finite element analyses was conducted to simulate the performance of CoSPSWs. Parametric analyses were performed to examine the effects of key geometry parameters, such as the height–thickness ratio, aspect ratio, horizontal panel width, and corrugation angle, affecting the buckling and failure modes and the strength of CoSPSWs. Then, the demand of the surrounding frame stiffness of the CoSPSWs was investigated based on the tension field distribution of CSPs. Finally, a modified strip model was designed to predict the shear performance of the CoSPSWs. The results revealed that the CoSPSWs, owing to the tension field effect, could resist greater loads after the inelastic buckling of infilled plates. However, the height–thickness ratio and aspect ratio should be restricted during the design of tall buildings. In addition, a formula for predicting the stiffness demand of the CoSPSW was derived. The results of the modified strip model agreed well with the previous experimental data.

Buffeting Response Prediction of Long-Span Bridges Based on Different Wind Tunnel Test Techniques

The traditional method for calculating the buffeting response of long-span bridges follows the strip assumption, and is carried out by identifying aerodynamic parameters through sectional model force or pressure measurement wind tunnel tests. However, there has been no report on predicting the buffeting response based on the sectional model vibration test. In recent years, the author has proposed a method, based on the integrated transfer function, for predicting the buffeting response of long-span bridges through theoretical and full-bridge tests. This provided an idea for predicting the buffeting response based on the sectional model vibration test. Unfortunately, the effectiveness and accuracy of this method have not been proven or demonstrated through effective tests. To solve this problem, a long-span suspension bridge was taken as a background. Parameters such as aerodynamic admittance were identified through a sectional model force measurement test and the integrated transfer functions were identified through a sectional model vibration test. A taut strip model test was also conducted. Furthermore, the buffeting response prediction results based on three kinds of wind tunnel test techniques were compared. The results showed that if the strip assumption was established, the results of the three methods aligned well, and that selecting a reasonable model aspect ratio for the test could effectively reduce the influence of the 3D effect; moreover, identifying the integrated transfer function by the sectional model vibration test could effectively predict the long-span bridge buffeting response. Furthermore, when the strip assumption failed, the results of the traditional calculation method using 3D aerodynamic admittance became smaller. A larger result would be obtained by neglecting the influence of aerodynamic admittance.

RETRACTED ARTICLE: Effect of cooling process on reducing residual stress of hot rolled high strength strip

ABSTRACT In order to analyse the influence of different laminar cooling technology on residual stress of steel strip, a finite-element model of strip was established with ABAQUS and FORTRAN named basic model. The evolution of temperature, phase transformation and stress of the strip during cooling process were expressed with coupling calculation. Other four finite-element models were established based on the basic model by changing its initial condition and boundary condition. The new models represented four cooling technology named edge masking, sparse cooling, posterior cooling and initial transverse temperature difference controlling. The results show that the stress distribution on strips tends to be high compressive stress on edge and tensile stress on middle section. The effect of the four cooling technologies on the residual stress reduction is ranked as initial transverse temperature difference controlling, sparse cooling, edge masking and posterior cooling.

Seismic design and performance of a steel frame-shear plate shear wall with self-centering energy dissipation braces structure

The steel plate shear wall with self-centering energy dissipation braces (SPSW-SCEDB) is a new seismic lateral resistant component. This paper outlines the performance requirements of the steel frame-shear plate shear wall with self-centering energy dissipation braces (SF-SCSPSW) structure and presents a direct displacement-based seismic design method for the structure. A combined strip model of the SPSW-SCEDB that considers the effect of the bolted connection on the wall plate is established. The comparison of the simulated and experimental results shows that the model can accurately predict the strength and hysteretic behavior under cyclic loading. The 8- and 15-story prototype buildings were designed using the presented method. The results of nonlinear dynamic analysis showed that larger inter-story deformations occurred on the lower floors, and the inter-story ratios gradually decreased with an increase in the number of floors. The maximum inter-story drift ratio (1.73%) of the 8-story structure under mega earthquakes and the maximum residual drift ratio (0.018%) of the 15-story structure under large earthquakes were less than the limit values (2% and 0.5%). Local yielding occurred between the brace connection and the column under mega earthquakes, but the columns remained in an elastic state. The seismic responses of the SPSW-SCEDBs in the two structures met the performance requirements of being elastic and suffering light and moderate and serious damage under frequent, medium, large, and mega earthquakes, respectively. The effectiveness of the proposed design method was verified.

Automated 2D Slice-Based Skull Stripping Multi-View Ensemble Model on NFBS and IBSR Datasets.

This study proposed and evaluated a two-dimensional (2D) slice-based multi-view U-Net (MVU-Net) architecture for skull stripping. The proposed model fused all three TI-weighted brain magnetic resonance imaging (MRI) views, i.e., axial, coronal, and sagittal. This 2D method performed equally well as a three-dimensional (3D) model of skull stripping. while using fewer computational resources. The predictions of all three views were fused linearly, producing a final brain mask with better accuracy and efficiency. Meanwhile, two publicly available datasets-the Internet Brain Segmentation Repository (IBSR) and Neurofeedback Skull-stripped (NFBS) repository-were trained and tested. The MVU-Net, U-Net, and skip connection U-Net (SCU-Net) architectures were then compared. For the IBSR dataset, compared to U-Net and SC-UNet, the MVU-Net architecture attained better mean dice score coefficient (DSC), sensitivity, and specificity, at 0.9184, 0.9397, and 0.9908, respectively. Similarly, the MVU-Net architecture achieved better mean DSC, sensitivity, and specificity, at 0.9681, 0.9763, and 0.9954, respectively, than the U-Net and SC-UNet for the NFBS dataset.

A Random Traffic Assignment Model for Networks Based on Discrete Dynamic Bayesian Algorithms

In this paper, a stochastic traffic assignment model for networks is proposed for the study of discrete dynamic Bayesian algorithms. In this paper, we study a feasible method and theoretical system for implementing traffic engineering in networks based on Bayesian algorithm theory. We study the implementation of traffic assignment engineering in conjunction with the network stochastic model: first, we study the Bayesian algorithm theoretical model of control layer stripping in the network based on the discrete dynamic Bayesian algorithm theory and analyze the resource-sharing mechanism in different queuing rules; second, we study the extraction and evaluation theory of traffic assignment for the global view obtained by the control layer of the network and establish the Bayesian algorithm analysis model based on the traffic assignment; subsequently, the routing of bandwidth guarantee and delay guarantee in the network is studied based on Bayesian algorithm model and Bayesian algorithm network random traffic allocation theory. In this paper, a Bayesian algorithm estimation model based on Bayesian algorithm theory is constructed based on network random observed traffic assignment as input data. The model assumes that the roadway traffic distribution follows the network random principle, and based on this assumption, the likelihood function of the roadway online traffic under the network random condition is derived; the prior distribution of the roadway traffic is derived based on the maximum entropy principle; the posterior distribution of the roadway traffic is solved by combining the likelihood function and the prior distribution. The corresponding algorithm is designed for the model with roadway traffic as input, and the reliability of the algorithm is verified in the arithmetic example.

The effect of MoS2–Ag/ H2O hybrid nanofluid on improving the performance of a solar collector by placing wavy strips in the absorber tube

We studied the optimization of a linear parabolic solar collector with a twisted tape (strip) aimed at increasing heat transfer in this paper. This research contains three sections. The first section focuses on the geometric study of various tapes, including twisted strips, wavy strips, and plain strips with a rectangular cross-section. In the second section, we examined the tape with the best efficiency at four heights. Finally, we assessed the effect of the H2O–Ag/MoS2 hybrid nanofluid in the third section. To this end, we simulated the governing equations and nanofluid flow in the collector using the ANSYS-Fluent software by employing the K−ε RNG turbulence model. The results revealed that the use of the twisted strip model brings the highest efficiency rate than other modes. Accordingly, the heat transfer rate and the outlet temperature for the twisted strip with the highest height increase by 14.33% and 0.39%, respectively compared to the lower heights. Besides, the use of composite nanofluid with a 5% concentration in a twisted strip with a height of 40 mm provides the highest heat transfer rate. Also, the outlet temperature difference with the fluid inlet increases by 4.93% compared to lower concentrations.

Continuous cycles of data-enabled design: reimagining the IoT development process

AbstractWith the emergence of Internet of Things (IoT) as a new source of “big” data and value creation, businesses encounter novel opportunities as well as challenges in IoT design. Although recent research argues that digital technology can enable new kinds of development processes that are distinctive from their counterparts in the 20th century, minimal attention has been focused on the IoT design process. In order to contextualize New Product Development (NPD) processes for IoT, this paper comprehensively interrogates existing, and emerging development approaches for products, services, software, and integrated products, and several factors that affect designing IoT. This discussion includes the generic development process, the commonalities and differences of different development approaches, and processes. The paper demonstrates that only a few existing approaches reflect vital characteristics of networked artifacts or the integration of data science within the development model, which is one of the key attributes of IoT design. From these investigations, we propose “The Mobius Strip Model of IoT Development ProcessI,” a conceptual process for IoT design, which is distinctive to others. The continuous loops of the IoT design integrate the attributes and phases of different processes and consist of two different development approaches and strategies. Understanding the particular attributes of the IoT NPD process can help novice and experienced researchers in both feeding and drawing insight from the broader design discourse.

Thermal and lighting evaluation in light roof prototypes, for hot humid climates

The zinc sheet roof is one of the most popular elements in Latin American architecture, and in many other regions with warm humid climates. Creating lighting and thermal alternatives focused on this typology would imply major benefits in the environmental and social fields. This study carried out in Manabí, Ecuador, evaluates three prototypes of light roofs, combining zinc with PVC, in order to determine the correct configuration of translucent material to create environments that are within thermal and lighting parameters. The results indicate that the empirical solutions model has the lowest variation in indoor temperature, with 32.63%, unlike the 32.97% of the cross-type model, and the 34.40% of the side strip model. Additionally, it was seen that the greatest influence of solar radiation on the roof is recorded from 1:00 p.m. to 2 p.m. approximately

Influence of kind of lightning stripe models on spectral characteristics of discharge phenomena inside aircraft nose radome model

Results of the experimental simulation of an influence of the lightning diverter strip models on spectral characteristics of discharge phenomena inside aircraft nose radome model, using artificial thunderstorm cell of a negative polarity, have presented. Significant influence of a lightning stripe model type on an amplitude and a form of the signals registered on an antenna model when discharge forms between an artificial thunderstorm cell a nose radome model and on the characteristics of their Fourier and wavelet spectrums has been experimentally established. It was found that the characteristic frequencies in the registered signals are on order higher for the segmented lightning stripes than for the solid lightning diverter stripes. Possible reasons of such differences are discussed in paper. Dependencies between the spectral characteristics of the signal registered on antenna inside a radome model and the parameters of the current impulses of discharge formed on both type of the lightning stripe models being on an external surface of a radome model have been established. Possibility of a correction of a lightning protection system of an aircraft nose radome for the decreasing of a signal intensity induced on antenna due to lightning, atmospheric and static electricity action has been analyzed and experimentally check including the frequency region dangerous for the radar and the computer equipment connected with them.

L-Galaxies 2020: the formation and chemical evolution of stellar haloes in Milky Way analogues and galaxy clusters

ABSTRACT We present an analysis of the formation and chemical evolution of stellar haloes around (a) Milky Way analogue (MWA) galaxies and (b) galaxy clusters in the L-Galaxies 2020 semi-analytic model of galaxy evolution. Observed stellar halo properties are better reproduced when assuming a gradual stripping model for the removal of cold gas and stars from satellites, compared to an instantaneous stripping model. The slope of the stellar mass–metallicity relation for MWA stellar haloes is in good agreement with that observed in the local Universe . This extends the good agreement between L-Galaxies 2020 and metallicity observations from the gas and stars inside galaxies to those outside. Halo stars contribute on average only ∼0.1 per cent of the total circumgalactic medium enrichment by z = 0 in MWAs, ejecting predominantly carbon produced by asymptotic giant branch stars. Around a quarter of MWAs have a single ‘significant progenitor’ with a mean mass of ∼$2.3\times {}10^{9}\, \rm {M}_{\odot }$, similar to that measured for Gaia Enceladus. For galaxy clusters, L-Galaxies 2020 shows good correspondence with observations of stellar halo mass fractions, but slightly overpredicts stellar masses. Assuming a Navarro–Frenk–White profile for the stellar halo mass distribution provides the best agreement. On average, the intracluster stellar component is responsible for 5.4 per cent of the total intracluster medium iron enrichment, exceeding the contribution from the brightest cluster galaxy by z = 0. We find that considering gradual stripping of satellites and realistic radial profiles is crucial for accurately modelling stellar halo formation on all scales in semi-analytic models.

Mechanism understanding for stripping electrochemistry of Li metal anode

Lithium metal batteries with theoretically high energy density are strongly considered as a potential electrochemical storage system. Dead lithium formed in the stripping process of lithium metal anode significantly hinders the practical applications. This review comprehensively summarizes the current research status about the stripping electrochemistry of lithium metal anode. The stripping models in different electrochemical scenarios are discussed. The factors affecting stripping processes and corresponding solutions are outlined. This review affords fresh insights to design robust lithium metal batteries based on the comprehensive understanding of the stripping electrochemistry. (DOI: https://doi.org/10.1002/sus2.37)

Mechanism understanding for stripping electrochemistry of Li metal anode

AbstractThe pursuit of sustainable energy has a great request for advanced energy storage devices. Lithium metal batteries are regarded as a potential electrochemical storage system because of the extremely high capacity and the most negative electrochemical potential of lithium metal anode. Dead lithium formed in the stripping process significantly contributes to the low efficiency and short lifespan of rechargeable lithium metal batteries. This review displays a critical review on the current research status about the stripping electrochemistry of lithium metal anode. The significance of stripping process to a robust lithium metal anode is emphasized. The stripping models in different electrochemical scenarios are discussed. Specific attention is paid to the understanding for the electrochemical principles of atom diffusion, electrochemical reaction, ion diffusion in solid electrolyte interphase (SEI), and electron transfer with the purpose to strengthen the insights into the behavior of lithium electrode stripping. The factors affecting stripping processes and corresponding solutions are summarized and categorized as follows: surface physics, SEI, operational and external factors. This review affords fresh insights to explore the lithium anode and design robust lithium metal batteries based on the comprehensive understanding of the stripping electrochemistry.

Shear lag including axial balance of box beams by finite segment model

A finite segment element including axial balance is formulated to describe shear lag in thin-walled box beams having constant or variable cross sections made from steel or other materials. The axial balance neglected in the conventional finite segment element model (CFSM) is enforced by adding the nodal longitudinal displacements, while shear lag and shear deformation are incorporated using the nodal shear lag functions and rotations, respectively. The homogeneous solutions deduced by the analytical method are utilized for constructing the element shape functions. By invoking the minimum potential energy theorem, the stiffness matrix and the equivalent nodal force vector are then derived for the element. The precision of the proposed finite segment model (PFSM) is verified against the results yielded from the solid finite element model (SFEM), the finite strip model (FSTM), and the experiments. A continuous box beam having varying cross sections is chosen for comparing the neutral axis depth to the centroidal axis depth. Subsequently, the influence of the axial balance on the mechanical behavior is evaluated. Moreover, the effects of three major geometric parameters are discussed for stress analysis. The results reveal that the proposed finite segment model is capable of reproducing the mechanical behavior of box beams having constant or varying cross sections, and that the stress analysis concerning the continuous box beam with variable cross sections is substantially affected by the axial balance condition.

Discussion: “Physical and numerical modelling of strip footing on geogrid reinforced transparent sand”By Jianfeng Chen, Xiaopeng Guo, Rui Sun, Sathiyamoorthy Rajesh, Song Jiang, Jianfeng Xue, J. Geotextile Geomembr, 49 (2), (April 2021), 399–412

• The results of the performed experiments may be impacted by the boundary effect. • To ensure the validity of the simulated model, the use of parameters that are representative of the test conditions is required. • The response of the geogrid employed is highly nonlinear, which is particularly important for the strain level considered in the analyses.

Reply to discussion by Mirmoradi on “Physical and numerical modelling of strip footing on geogrid reinforced transparent sand”

• The chosen test configurations have insignificant boundary effect and would not alter the failure mechanism of foundations. • The load-strain behavior obtained from geogrid tensile test can represent the behavior of reinforcement in foundation soils. • Numerical analysis by introducing the plane strain friction angles is of significance for comparison with existing study.

Vortex-induced vibration of a flexible rectangular cylinder: Experimental investigation and comparative study of theoretical models

The vortex-induced vibration (VIV) of slender flexible structures is usually estimated based on two-dimensional aerodynamic parameters determined by sectional model wind tunnel tests. Before converting such test results into a prototype flexible structure, many complicated factors, such as the spanwise correlation of aerodynamic force and vibration mode shape, should be considered. In this study, wind tunnel tests of a 5:1 rectangular taut strip model and its sectional model with the same geometry were first conducted to analyze the relationship between the VIV amplitude of the flexible structure and sectional model. The results showed that the taut strip model sustained an approximately 15% higher VIV amplitude than the sectional model, indicating that the VIV amplitude could be underestimated if the sectional model test results were directly used. Next, based on the identified spanwise correlation function of the 5:1 rectangular cylinder, several existing VIV response estimation approaches based on Scanlan's semi-empirical vortex-induced force (VIF) model were examined and compared. Finally, an improved approach was proposed by which the correlation coefficients based on the partial spanwise correlation theory could be approximated with more comprehensive consideration of the spanwise correlation, allowing for a more accurate evaluation of the VIV amplitude for flexible structures.

Amidation Reaction System: Kinetic Studies and Improvement by Product Removal.

The amidation reaction to produce fatty acid diethanolamide is an important unit process to produce surfactants from renewable sources rather than from petroleum sources. Amidation is a liquid-phase reaction between diethanolamine with a fatty acid methyl ester. Since the reaction is reversible, the conversion is limited by equilibrium, the side product being methanol, which is volatile. Hence, mass transfer effects need to be considered in the interpretation of kinetic data. Further, the elimination of methanol can help to shift the reaction forward. Thus, the process has the potential for process intensification. This paper provides a batch reactor model to interpret the simulation data and includes mass transfer effects analyzed using a dimensionless mass transfer parameter (αlg). Using values of this parameter greater than 4 leads to an equilibrium model where the methanol partial pressure in the bulk gas approaches that at the interface. Using this model, the kinetic and equilibrium parameters for the amidation reaction were determined using experimental data in the first part of this study. The experimental data for fitting the parameters are obtained from a closed batch reactor operated with an initial pressure of 1 bar and a temperature range of 70–80 °C. The second part of the paper examines two process-intensification concepts—viz., inert gas and vacuum stripping of methanol from the reactor—and simulates the process in the form of mass-transfer-based models. Improvement in the final conversion was demonstrated in both approaches, and predictions of the vacuum stripping model are in good agreement with the experimental results. Thus, the developed vacuum stripping model is useful for accurate analysis and design of a reactor with vacuum stripping. The novelty of the work is obtaining rate and reaction equilibrium constants, enthalpy of reaction, and liquid activity coefficient for amidation, which have no prior reporting, and providing the viability of options for side product removal. The applied modeling approaches and the experimental facilities and methods are established.