In this work,the microstructure,hydrogen storage properties,anti-oxide ability and rate limiting step of Zr(Cr_(1−x)Co_(x))_(2)(x=0,0.2,0.4 and 0.6)alloys have been investigated.After studying the crystal structure,we...In this work,the microstructure,hydrogen storage properties,anti-oxide ability and rate limiting step of Zr(Cr_(1−x)Co_(x))_(2)(x=0,0.2,0.4 and 0.6)alloys have been investigated.After studying the crystal structure,we found that all alloy samples could show C14-type phase but the alloy sample x=0 could also show a small amount of Cr phase.Rietveld fitting showed that lattice parameter and unit cell volume of C14-type phase decreased with increasing x.After further research,it was clear that the first hydrogen absorption capacity decreased with increasing x.But introducing more Co content had a positive influence on the effective hydrogen storage capacity and cyclic hydrogen absorption and desorption properties of the alloy sample.We also found that adding Co to ZrCr_(2)alloy could improve its anti-oxide ability.In addition to this,the rate limiting step model was also studied.展开更多
The method of nonlinear finite element reliability analysis (FERA) of slope stability using the technique of slip surface stress analysis (SSA) is studied. The limit state function that can consider the direction of s...The method of nonlinear finite element reliability analysis (FERA) of slope stability using the technique of slip surface stress analysis (SSA) is studied. The limit state function that can consider the direction of slip surface is given, and the formula-tions of FERA based on incremental tangent stiffness method and modified Aitken accelerating algorithm are developed. The limited step length iteration method (LSLIM) is adopted to calculate the reliability index. The nonlinear FERA code using the SSA technique is developed and the main flow chart is illustrated. Numerical examples are used to demonstrate the efficiency and robustness of this method. It is found that the accelerating convergence algorithm proposed in this study proves to be very efficient for it can reduce the iteration number greatly, and LSLIM is also efficient for it can assure the convergence of the iteration of the reliability index.展开更多
As structure buckling problems easily arise when supercavitating projectiles operate with high underwater velocity, it is necessary to perform structure buckling reliability analysis. Now it is widely known that proba...As structure buckling problems easily arise when supercavitating projectiles operate with high underwater velocity, it is necessary to perform structure buckling reliability analysis. Now it is widely known that probabilistic and non-probabilistic uncertain information exists in engineering analysis. Based on reliability comprehensive index of multi-ellipsoid convex set, probabilistic uncertain information is added and transferred into non-probabilistic interval variable. The hybrid reliability is calculated by a combined method of modified limit step length iteration algorithm(MLSLIA) and Monte-Carlo method. The results of engineering examples show that the convergence of MLSLIA is better than that of limit step length iteration algorithm(LSLIA). Structure buckling hybrid reliability increases with the increase of ratio of base diameter to cavitator diameter, and decreases with the increase of initial launch velocity. Also the changes of uncertain degree of projectile velocity and cavitator drag coefficient affect structure buckling hybrid reliability index obviously. Therefore, uncertain degree of projectile velocity and cavitator drag coefficient should be controlled in project for high structure buckling reliability.展开更多
基金supported by Natural Science Foundation of Jiangxi Province(20202BABL214003)Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation(JXMS202008 and JXMS202009)+4 种基金Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices(PMND201902)Engineering Research Center of Nuclear Technology Application(East China University of Technology)Ministry of Education(HJSJYB2019–5)Science and Technology Project Founded by Education Department of Jiangxi Province(GJJ190406)Research Foundation for Advanced Talents of East China University of Technology(DHBK2019091).
文摘In this work,the microstructure,hydrogen storage properties,anti-oxide ability and rate limiting step of Zr(Cr_(1−x)Co_(x))_(2)(x=0,0.2,0.4 and 0.6)alloys have been investigated.After studying the crystal structure,we found that all alloy samples could show C14-type phase but the alloy sample x=0 could also show a small amount of Cr phase.Rietveld fitting showed that lattice parameter and unit cell volume of C14-type phase decreased with increasing x.After further research,it was clear that the first hydrogen absorption capacity decreased with increasing x.But introducing more Co content had a positive influence on the effective hydrogen storage capacity and cyclic hydrogen absorption and desorption properties of the alloy sample.We also found that adding Co to ZrCr_(2)alloy could improve its anti-oxide ability.In addition to this,the rate limiting step model was also studied.
基金supported by the National Natural Science Foundation of China (No. 50748033)the Specific Foundation for PhD of Hefei University of Technology (No. 2007GDBJ044), China
文摘The method of nonlinear finite element reliability analysis (FERA) of slope stability using the technique of slip surface stress analysis (SSA) is studied. The limit state function that can consider the direction of slip surface is given, and the formula-tions of FERA based on incremental tangent stiffness method and modified Aitken accelerating algorithm are developed. The limited step length iteration method (LSLIM) is adopted to calculate the reliability index. The nonlinear FERA code using the SSA technique is developed and the main flow chart is illustrated. Numerical examples are used to demonstrate the efficiency and robustness of this method. It is found that the accelerating convergence algorithm proposed in this study proves to be very efficient for it can reduce the iteration number greatly, and LSLIM is also efficient for it can assure the convergence of the iteration of the reliability index.
基金the National Natural Science Foundation of China(No.51305421)the National Defense Technology Basis Research Project(No.JSZL2014130B005)the Development of Science and Technology Project of Jilin Province(No.20140520137JH)
文摘As structure buckling problems easily arise when supercavitating projectiles operate with high underwater velocity, it is necessary to perform structure buckling reliability analysis. Now it is widely known that probabilistic and non-probabilistic uncertain information exists in engineering analysis. Based on reliability comprehensive index of multi-ellipsoid convex set, probabilistic uncertain information is added and transferred into non-probabilistic interval variable. The hybrid reliability is calculated by a combined method of modified limit step length iteration algorithm(MLSLIA) and Monte-Carlo method. The results of engineering examples show that the convergence of MLSLIA is better than that of limit step length iteration algorithm(LSLIA). Structure buckling hybrid reliability increases with the increase of ratio of base diameter to cavitator diameter, and decreases with the increase of initial launch velocity. Also the changes of uncertain degree of projectile velocity and cavitator drag coefficient affect structure buckling hybrid reliability index obviously. Therefore, uncertain degree of projectile velocity and cavitator drag coefficient should be controlled in project for high structure buckling reliability.
