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On an isotropic porous solid cylinder:the analytical solution and sensitivity analysis of the pressure

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1499-1522页

作者： H.ASGHARI L.MILLER R.PENTA J.MERODIO Departamento de Matematica Aplicada a las TIC ETS de Ingenieria de Sistemas InformaticosUniversidad Politecnica de MadridMadrid 28031Spain School of Mathematics and Statistics University of GlasgowGlasgow G128QQU.K.

Within this work,we perform a sensitivity analysis to determine the influence of the material input parameters on the pressure in an isotropic porous solid *** provide a step-by-step guide to obtain the analytical solution for a porous isotropic elastic cylinder in terms of the pressure,stresses,and elastic *** obtain the solution by performing a Laplace transform on the governing equations,which are those of Biot's poroelasticity in cylindrical polar *** enforce radial boundary conditions and obtain the solution in the Laplace transformed domain before reverting back to the time *** sensitivity analysis is then carried out,considering only the derived pressure *** analysis finds that the time t,Biot's modulus M,and Poisson's ratio ν have the highest influence on the pressure whereas the initial value of pressure P_(0) plays a very little role.

关键词： sensitivity analysis Laplace transform cylindrical polar coordinate Biot's modulus cylinder

Calculations and sensitivity analysis of Chlorine-,NO_(x)-,and Bromine-Depleting Cycles of Stratospheric Ozone

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Journal of Environmental Science and Engineering(B) 2024年第2期13卷 53-69页

作者： Ibraheem Alelmi Sen Nieh Department of Mechanical Engineering the Catholic University of AmericaWashington DC 20064the United States College of Engineering Yuan Ze UniversityTaoyuan 32003Taiwan

This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the *** considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative *** against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N *** deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were *** chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone *** analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline *** combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone *** total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration *** the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere.

关键词： Ozone depletion 2-D model chlorine bromine nitrogen oxides sensitivity analysis total ozone abundance DU

sensitivity analysis of the deterioration of concrete strength in marine environment to multiple corrosive ions

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Frontiers of Structural and Civil Engineering 2022年第2期16卷 175-190页

作者： Jinwei YAO Jiankang CHEN Zhejiang Business Technology Institute Ningbo315012China Key Laboratory of Impact and Safety Engineering Ministry of EducationSchool of Mechanical Engineering and MechanicsNingbo UniversityNingbo315211China

The corrosion degradation behavior of concrete materials plays a crucial role in the change of its mechanical properties under multi-ion interaction in the marine *** this study,the variation in the macrophysical and mechanical properties of concrete with corrosion time is investigated,and the source of micro-corrosion products under different salt solutions in seawater are *** of the continuous hydration effect of concrete,the damage effects of various corrosive ions(Cl^(−),SO_(4)^(2−),and Mg^(2+),etc.)on the tensile and compressive strength of concrete are discussed based on measurement in different salt *** sensitivity analysis method for concrete strength is used to quantitatively analyze the sensitivity of concrete strength to the effects of each ion in a multi-salt solution without considering the influence of continued *** quantitative results indicate that the addition of Cl−can weaken the corrosion effect of SO_(4)^(2−) by about 20%,while the addition of Mg^(2+)or Mg^(2+)and Cl^(−)can strengthen it by 10%–20%during a 600-d corrosion process.

关键词： sensitivity analysis concrete strength corrosion deterioration multi-ion interaction marine environment

sensitivity analysis Approach to Multibody Systems Described by Natural Coordinates

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 402-410页

作者： LI Xiufeng WANG Yabin State Key Laboratory of Electromechanical Dynamic Control Beijing Institute of Technology

The classical natural coordinate modeling method which removes the Euler angles and Euler parameters from the governing equations is particularly suitable for the sensitivity analysis and optimization of multibody systems. However, the formulation has so many principles in choosing the generalized coordinates that it hinders the implementation of modeling automation, A first order direct sensitivity analysis approach to multibody systems formulated with novel natural coordinates is presented. Firstly, a new selection method for natural coordinate is developed. The method introduces 12 coordinates to describe the position and orientation of a spatial object. On the basis of the proposed natural coordinates, rigid constraint conditions, the basic constraint elements as well as the initial conditions for the governing equations are derived. Considering the characteristics of the governing equations, the newly proposed generalized-ct integration method is used and the corresponding algorithm flowchart is discussed. The objective function, the detailed analysis process of first order direct sensitivity analysis and related solving strategy are provided based on the previous modeling system Finally, in order to verify the validity and accuracy of the method presented, the sensitivity analysis of a planar spinner-slider mechanism and a spatial crank-slider mechanism are conducted. The test results agree well with that of the finite difference method, and the maximum absolute deviation of the results is less than 3%. The proposed approach is not only convenient for automatic modeling, but also helpful for the reduction of the complexity of sensitivity analysis, which provides a practical and effective way to obtain sensitivity for the optimization problems of multibody systems.

关键词： sensitivity analysis direct differentiation method natural coordinates multibody systems

sensitivity analysis for axis rotation diagrid structural systems according to brace angle changes

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Earthquake Engineering and Engineering Vibration 2017年第4期16卷 783-791页

作者： Jae-Kwang Yang Long-Yang Li Sung-Soo Park Department of Architectural Engineering Pusan National UniversityKorea Department of Architectural Engineering Pusan National UniversityDoctor of EngineeringKorea

General regular shaped diagrid structures can express diverse shapes because braces are installed along the exterior faces of the structures and the structures have no columns. However, since irregular shaped structures have diverse variables, studies to assess behaviors resulting from various variables are continuously required to supplement the imperfections related to such variables. In the present study, materials elastic modulus and yield strength were selected as variables for strength that would be applied to diagrid structural systems in the form of Twisters among the irregular shaped buildings classified by Vollers and that affect the structural design of these structural systems. The purpose of this study is to conduct sensitivity analysis for axial rotation diagrid structural systems according to changes in brace angles in order to identify the design variables that have relatively larger effects and the tendencies of the sensitivity of the structures according to changes in brace angles and axial rotation angles.

关键词： sensitivity analysis axial rotation-diagrid structure lateral behaviors

sensitivity analysis and probability modelling of the structural response of a single-layer reticulated dome subjected to an external blast loading

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Defence Technology（防务技术） 2023年第5期23卷 152-163页

作者： Shao-bo Qi Guang-yan Huang Xu-dong Zhi Feng Fan State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081PR China Key Lab of Structure Dynamic Behaviour and Control of the Ministry of Education Harbin Institute of TechnologyHarbin150090China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin150090China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China

The structural response of a single-layer reticulated dome to external explosions is shaped by many variables,and the associated uncertainties imply non-deterministic *** deterministic methods for predicting the consequences of specific explosions do not account for these ***,the impact of the uncertainties associated with these input variables on the structures’response needs to be studied and *** this study,a parametric uncertainty analysis was conducted ***,local and global sensitivity analyses were carried out to identify the drivers of the structural dynamic response.A probabilistic structural response model was established based on sensitive variables and a reasonable sample ***,some deterministic empirical methods for explosion-resistance design,including the plane blast load model of CONWEP,the curved blast load model under the 50%assurance level,and the 20%mass-increased method,were used for evaluating their *** results of the analyses revealed that the structural response of a single-layer reticulated dome to an external blast loading is lognormally ***,the MB0.5 method based on the curved reflector load model yielded results with a relatively stable assurance rate and reliability,but CONWEP did not;thus,the 1.2MB0.5 method can be used for making high-confidence simple *** addition,the results indicated that the structural response is very sensitive to the explosion *** on these results,it is suggested that for explosion proofing,setting up a defensive barrier is more effective than structural strengthening.

关键词： Dome structure Blast load uncertainty sensitivity analysis Probabilistic investigation Reliability evaluation

sensitivity analysis of Pollutants and Pattern Factor in a Gas Turbine Model Combustor due to Changes in Stabilizing Jets Characteristics

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Journal of Thermal Science 2022年第5期31卷 1622-1641页

作者： BAZDIDI-TEHRANI Farzad TEYMOORI Alireza GHIYASI Mehdi School of Mechanical Engineering Iran University of Science and TechnologyTehran16846-13114Iran

In the present paper,a sensitivity analysis of pollutants and pattern factor in a model combustor due to changes in the geometrical characteristics of stabilizing jets has been carried *** exhaust pollutants including NO_(x),CO and soot have been chosen due to their harmful effect on the *** pattern factor has been also considered owing to its impact on turbine *** geometrical characteristics comprise diameter,angle and position of stabilizing ***-Lagrangian approach has been employed to model liquid fuel injection and distribution,breakup and evaporation of *** the analysis of reactive-spray flow characteristics,RANS approach,realizable k-εturbulence model,discrete ordinates radiative heat transfer model and steady flamelet combustion model together with the chemical reaction mechanism of diesel fuel(C_(10)H_(22))have been ***_(x) modeling has been performed via *** analysis is such that by making variations in the problem inputs(diameter,angle and position of jets)in an organized manner,the effects on the outputs(NO_(x),CO,soot and pattern factor)are *** number and order of simulations are predicted by design of experiments and full factorial *** have been analyzed using analysis of *** has been observed that if interactions among the characteristics of jets are considered,it is possible to analyze the exhaust pollutants more *** fact,by using the interactions,it is likely to find a point where all output parameters are *** show that by considering interactions of stabilizing jet characteristics,the maximum values of NO_(x),CO,soot and pattern factor change from 13.927 ppm,11.198%mole fraction,2.877 ppm and 0.043 to 26.233 ppm,14.693%mole fraction,142.357 ppm and 0.060,***,the minimum values change from 5.819 ppm,7.568%mole fraction,0.013 ppm and 0.029 to 6.098 ppm,5.987%mole fraction,0.002 ppm and 0.027,respectively.

关键词： model jet-stabilized combustor liquid fuel injection sensitivity analysis design of experiments pollutants pattern factor

sensitivity analysis for Safety Design Verification of General Aviation Reciprocating Aircraft Engine

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Chinese Journal of Aeronautics 2012年第5期25卷 675-680页

作者： CAO Jiaokun DING Shuiting Airworthiness Technologies Research Center Beihang UniversityBeijing 100191China

This paper presents an application of global sensitivity analysis for system safety analysis of reciprocating aircraft engine. Compared with local sensitivity analysis results, global sensitivity analysis could provide more information on parameter inter- actions, which are significant in complex system safety analysis. First, a deterministic aviation reciprocating engine thermody- namics model is developed and parameters of interest are defined as random variables. Then, samples are generated by Monte Carlo method for the parameters used in engine model on the basis of definition of factor distribution. Eventually, results from engine model are generated and importance indices are calculated. Based on the analysis results, design is improved to satisfy the airworthiness requirements. The results reveal that by using global sensitivity analysis, the parameters could be ranked with respect to their importance, including first order indices and total sensitivity indices. By reducing the uncertainty of parameters and adjusting the range of inputs, safety criteria would be satisfied.

关键词： sensitivity analysis safety analysis airworthiness reciprocating aircraft engine design verification

sensitivity analysis of mesoscale structural parameters for simulation of fluidized beds

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Particuology 2019年第6期17卷 77-93页

作者： Wenming Liu Hongzhong Li Qingshan Zhu Chaoquan Hu Sinopec Research Institute of Petroleum Processing Beijing 100083China State Key Laboratory of Multi-Phase Complex Systems Institute of Process EngineeringChinese Academy of SciencesP.O.Box 353Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

This study presents new numerical drag models with which to analyze the sensitivity of mesoscale structural parameters in bubbling,turbulent,and circulating fluidized *** drag models are derived using the method of transfer-coefficient-based structural parameters(TC-SP).Analyzing the sensitivity of the structural parameters reveals that the coefficients associated with drag are more sensitive to parameters in the dense phase than to those in the dilute phase,especially the superficial slip *** the basis of these results,the TC-SP drag model is simplified ***,despite having half the number of parameters of conventional structure-based drag models,the simplified TC-SP drag model achieves simulation results that are equally or more *** simple calculations and improved accuracy using coarse grids,the model reported in this study is capable of predicting the hydrodynamics of the three types of fluidized beds.

关键词： Fluidization Simulation sensitivity analysis Dense phase Drag