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A Novel Deep Learning Based Healthcare Model for COVID-19 Pandemic stress analysis

Computers, Materials & Continua 2022年第9期72卷 6029-6044页

作者： Ankur Dumka Parag Verma Rajesh Singh Anil Kumar Bisht Divya Anand Hani Moaiteq Aljahdali Irene Delgado Noya Silvia Aparicio Obregon Computer Science and Engineering Women Institute of TechnologyUttarakhand-248007India Chitkara University Institute of Engineering and Technology Chitkara UniversityPunjabIndia Research and Innovation Uttranchal UniversityDehradunUttrakhand248007India Department of Computer Science&IT MJP Rohilkhand UniversityBareilly236006UPIndia Computer Science and Engineering Lovely Professional UniversityPunjab144411India Higher Polytechnic School Universidad Europea del Atlántico39011SantanderSpain Faculty of Computing and Information Technology King Abdulaziz University37848JeddahSaudi Arabia Universidad Internacional Iberoamericana CampecheMexico Universidade Internacional do Cuanza Bairro Kaluanda EN 250CuitoBié.Angola

Coronavirus(COVID-19)has impacted nearly every person across the globe either in terms of losses of life or as of lockdown.The current coronavirus(COVID-19)pandemic is a rare/special situation where people can express their feelings on Internet-based social networks.Social media is emerging as the biggest platform in recent years where people spend most of their time expressing themselves and their emotions.This research is based on gathering data from Twitter and analyzing the behavior of the people during the COVID-19 lockdown.The research is based on the logic expressed by people in this perspective and emotions for the suffering of COVID-19 and lockdown.In this research,we have used a Long Short-Term Memory(LSTM)network model with Convolutional Neural Network using Keras python deep-learning library to determine whether social media platform users are depressed in terms of positive,negative,or neutral emotional out bust based on their Twitter posts.The results showed that the model has 88.14%accuracy(representation of the correct prediction over the test dataset)after 10 epochs which most tweets showed had neutral polarity.The evaluation shows interesting results in positive(1),negative(–1),and neutral(0)emotions through different visualization.

关键词： COVID-19 lockdown stress analysis depression analysis sentiment analysis social media COVID-19 twitter dataset coronavirus

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stress analysis of functionally graded rotating discs: analytical and numerical solutions

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Acta Mechanica Sinica 2011年第6期27卷 950-955页

作者： Hasan Callioglu Numan Behll Bektas Metin Sayer Department of Mechanical Engineering Pamukkale University

This study deals with stress analysis of annular rotating discs made of functionally graded materials（FGMs）.Elasticity modulus and density of the discs are assumed to vary radially according to a power law function,but the material is of constant Poisson＇s ratio.A gradient parameter n is chosen between 0 and 1.0.When n = 0,the disc becomes a homogeneous isotropic material.Tangential and radial stress distributions and displacements on the disc are investigated for various gradient parameters n by means of the diverse elasticity modulus and density by using analytical and numerical solutions.Finally,a homogenous tangential stress distribution and the lowest radial stresses along the radius of a rotating disc are approximately obtained for the gradient parameter n = 1.0 compared with the homogeneous,isotropic case n = 0.This means that a disc made of FGMs has the capability of higher angular rotations compared with the homogeneous isotropic disc.

关键词： Functional graded materials stress analysis Analytical analysis Finite element analysis （FEA）

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55 Years of Holographic Non-Destructive Testing and Experimental stress analysis:Is there still Progress to be expected?

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Light(Advanced Manufacturing) 2022年第1期3卷 98-113页

作者： Wolfgang Osten Giancarlo Pedrini Institute for Applied Optics ITO University Stuttgart Pfaffenwaldring 9 70569 StuttgartGermany

Holographic methods for non-destructive testing,shape measurement,and experimental stress analysis have shown to be versatile tools for the solution of many inspection problems.Their main advantages are the non-contact nature,the non-destructive and areal working principle,the fast response,high sensitivity,resolution and precision.In contrast to conventional optical techniques such as classical interferometry,the holographic principle of wavefront storage and reconstruction makes it possible to investigate objects with rough surfaces.Consequently,the response of various classes of products on operational or artificial load can be examined very elegantly.The paper looks back to the history of holographic metrology,honors the inventors of the main principles,discusses criteria for the selection of a proper inspection method,and shows exemplary applications.However,the main focus is on modern developments that are inspired by the rapid technological process in sensing technology and digitization,on current applications and future challenges.

关键词： Non-Destructive Testing Holography stress analysis Digital Holography Speckle Interferometry

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stress analysis of Printed Circuit Board with Different Thickness and Composite Materials Under Shock Loading

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Computer Modeling in Engineering & Sciences 2020年第2期122卷 661-674页

作者： Kuan-Ting Liu Chun-Lin Lu Nyan-Hwa Tai Meng-Kao Yeh Department of Power Mechanical Engineering National Tsing Hua UniversityHsinchu30013Taiwan. Department of Materials Science and Engineering National Tsing Hua UniversityHsinchu30013Taiwan.

In this study,the deformation and stress distribution of printed circuit board(PCB)with different thickness and composite materials under a shock loading were analyzed by the finite element analysis.The standard 8-layer PCB subjected to a shock loading 1500 g was evaluated first.Moreover,the finite element models of the PCB with different thickness by stacking various number of layers were discussed.In addition to changing thickness,the core material of PCB was replaced from woven E-glass/epoxy to woven carbon fiber/epoxy for structural enhancement.The non-linear material property of copper foil was considered in the analysis.The results indicated that a thicker PCB has lower stress in the copper foil in PCBs under the shock loading.The stress difference between the thicker PCB(2.6 mm)and thinner PCB(0.6 mm)is around 5%.Using woven carbon fiber/epoxy as core material could lower the stress of copper foil around 6.6%under the shock loading 1500 g for the PCB with 0.6 mm thickness.On the other hand,the stress level is under the failure strength of PCBs with carbon fiber/epoxy core layers and thickness 2.6 mm when the peak acceleration changes from 1500 g to 5000 g.This study could provide a reference for the design and proper applications of the PCB with different thickness and composite materials.

关键词： stress analysis printed circuit board composite material finite element analysis shock loading.

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stress analysis OF INJECTION MOLDED PARTS IN POST-FILLING STAGE

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Chinese Journal of Mechanical Engineering 2000年第1期13卷 41-46页

作者： Jiang Tao Chen Xing Li Dequn (National Key ho of Plastic Simulation & Molding Technology Huazhong University of Science & Technology) 华中科技大学塑性成形模拟及模具技术国家重点实验室湖北武汉

The linear isothermo-viscoelastic constitutive equation is established according to the principle of viscoelastic mechanics. Given the boundary conditions of the temperature field, the linear thermo-viscoelastic constitutive equation is established acording to the analysis of the thermorheologically simple. The stress analysis model is constructed on the base of some reasonable hypotheses which consider the restraint conditions of mold and the characteristics of injection molding in the post-filling stage. The mathematical model is calculated by the finite difference method. The results can help to predict the warpage of plastic products.

关键词： Injection molding stress analysis Thermo-viscoelastic Laplace transform

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Finite Element Method analysis of the stress for Line Pipe with Corrode Groove During Outdoor Storage

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Acta Metallurgica Sinica(English Letters) 2013年第2期26卷 188-198页

作者： Zhuanzhao YANG Daoxin LIU Xiaohua ZHANG Northwestern Polytechnical University

The basic principle of corrode groove on outside of steel pipe during storage was analyzed in this paper, namely the water film on the contacted surface of steel pipe, which gathered from humidity in the air, rain or gel, and the suspended particles in air, and the corrosive composition, such as SO2, CO2, O2 and NaCI, in addition to the inhomogeneity of the organization and composition, which lead to the corrosion cell reaction, so that cause the corrosion initial from the contact surface of the between steel pipes, so as to form the corrosion groove. At the same time, the corrosion groove with depth of 0.125t （t pipe wall thickness） on the pipe of φ 1016 mm×21 mm ×70 API SPEC 5L was simulated using the FEM （finite element method）, and the stress and strain distribution of the defect area near corrosion groove were solved at the inner pressure of 12 MPa, 10 MPa, 8 MPa, 6 MPa, 4 MPa and 2 MPa, respectively, which showed that no matter the pressure values were, the maximum stress and strain were lied at the bottom of corrosion defects groove and were in good linear relationship with the internal pressure increasing from 2 MPa to 6 MPa. When the internal pres- sures were greater than 6 MPa, they felled into the nonlinear model and to be yielded or even to be destroyed. In addition, the residual strength and the limit operation pressure of the corrode pipe with the defects groove of 0.125t were calculated or simulated according to the theoretical calculation, the finite element method based on the stress, the finite element method based on strain, DNV-RP-F101, ASME B31G and experimental methods respectively. The results showed that the residual strength and the limit operation pressure of the defective parts solved by the finite element method based on stress were 424 MPa, and 15.34 MPa, respectively, which was very close to that of experimental method, the residual strength was 410 MPa and the limit operation pressure 14.78 MPa. Besides, the results also showed that it was feasible and effective to simulate the resi

关键词： Finite element methods （FEM） Storage Corrode Groove stress analysis von Mises equivalent stress

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Vibration Response and stress analysis of Planar Elastic Tube Bundle Induced by Fluid Flow

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 89-96页

作者： De-Rong Duan Pei-Qi Ge Wen-Bo Bi Yan-Ying Dong School of Mechanical Engineering Shandong University Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education Shandong University

Flow?induced vibration plays a positive role on heat transfer enhancement. Meanwhile, it is also a negative factor for fatigue strength. Satisfying the fatigue strength is the primary prerequisite for heat transfer enhancement. This paper numerically studied the flow?induced vibration of planar elastic tube bundle based on a two?way fluid–structure interaction(FSI) calculation. The numerical calculation involved the unsteady, three?dimensional incompressible governing equations solved with finite volume approach and the dynamic balance equation of planar elastic tube bundle solved with finite element method combined with dynamic mesh scheme. The numerical approach was verified by comparing with the published experimental results. Then the vibration trajectory, deformation and stress contour of planar elastic tube bundle were all studied. Results show that the combined movement of planar elastic tube bundle represents the agitation from inside to outside. The vibration of out?of?plane is the main vibration form with the typically sinusoidal behavior because the magnitude of displacement along the out?of?plane direction is the 100 times than the value of in?plane direction. The dangerous point locates in the innermost tube where the equivalent stress can be utilized to study the multiaxial fatigue of planar elastic tube bundle due to the alternating stress concentration. In the velocity range of 0.2-3 m/s, it is inferred that the vibration amplitude plays a role on the stress response and the stress amplitude is susceptible to the fluid velocity. This research paves a way for studying the fatigue strength of planar elastic tube bundle by flow?induced vibration.

关键词： Flow?induced vibration Planar elastic tube bundle Vibration response stress analysis

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Nonlinear Static Finite Element stress analysis of Pipe-in-Pipe Risers

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China Ocean Engineering 2005年第1期19卷 155-166页

作者：周宏杰闫澍旺崔溦 School of Construction Engineering Tianjin University Tianjin 300072 China

Owing to the complexity of the pipe-in-pipe (PIP) riser system in structure, load and restraint, many problems arise in the structural analysis of the system. This paper presents a new method for nonlinear static finite element stress analysis of the PIP riser system. The finite element (FE) model of the PIP riser system is built via software AutoPIPE 6.1. According to the specialties of a variety of components in the PIP riser system, different elements are used so as to model the system accurately. Allowing for the complication in modeling the effects of seabed restraint, a technique based on the bilinear spring concept is developed to calculate the soil properties. Then, based on a pipeline project, the entire procedure of stress analysis is discussed in detail, including creation of an FE model, processing of input data and analysis of results. A wide range of loading schemes is investigated to ascertain that the stresses remain within the acceptable range of the pipe material strength. Finally, the effects of the location of flanges, the thermal expansion of submarine pipelines and the seabed restraint on stress distribution in the riser and expansion loop are studied, which are valuable for pipeline designers.

关键词： pipe-in-pipe stress analysis pipe-soil interaction riser FE

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A NEW METHOD FOR stress analysis OF A CYCLICALLY SYMMETRIC STRUCTURE

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Applied Mathematics and Mechanics(English Edition) 2000年第1期21卷 89-96页

作者：唐国安丁俊徐小峰 Department of Applied Mechanics Fudan University Shanghai P R China

In this paper, a computational method for finite element stress analysis of a cyclically symmetric structure subjected to arbitrary loads is provided. At first, using discrete Fourier transformation technique, the complete structure is analyzed by considering only one sector with appropriate complex constraints on its boundary with the adjacent sectors. Next, an imaginary structure which is composed of two identically overlapping sectors is constructed, and that the complex constraints mentioned above can be equivalently replaced by a set of real constraints on this imaginary structure is proved. Therefore, the stress analysis of a cyclically symmetric structure can be solved conveniently by most of finite element programs.

关键词： cyclically symmetric structure finite element method stress analysis

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THREE-DIMENSIONAL ISODYNE stress analysis——PRESENT STATE, TRENDS, THEORETICAL PROBLEMS

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Acta Mechanica Sinica 1995年第2期11卷 97-121页

作者： JerzyT.Pindera Univ. of Waterloo Dept. of Civil Engng. Solid Mechanics Division Experimental MechanicsWaterloo Ontario Canada N2L 3G1

The paper presents and discusses theoretical bases and methodology of development of two- and three-dimensional analytical and optical isodynes. Atten- tion is given to the theoretical admissibility of the major components of the physical and mathematical models which are taken as the theoretical basis of the isodynes, and of the related analytical and experimental procedures of stress analysis. Efficiency and reliability of the nondestructive isodyne stress analysis are discussed.

关键词： stress analysis isodynes modeling criteria reliability physical and analytical models theoretical and practical admissibility testing reliability of procedures

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