A method of the fuzzy cross-correlation factor exponent in dynamics is researched and proposed to diagnose abnormality of cracks in the concrete dam. Moreover, the Logistic time series changing from period-doubling bi...A method of the fuzzy cross-correlation factor exponent in dynamics is researched and proposed to diagnose abnormality of cracks in the concrete dam. Moreover, the Logistic time series changing from period-doubling bifurcation to chaos is tested first using this method. Results indicate that it can distinguish inherent dynamics of time series and can detect mutations. Considering that cracks in the concrete dam constitute an open, dissipative and complex nonlinear dynamical system, a typical crack on the downstream face of a concrete gravity arch dam is analyzed with the proposed method. Two distinct mutations are discovered to indicate that the abnormality diagnosis of cracks in the concrete dam is achieved dynamically through this method. Furthermore, because it can be directly utilized in the measured crack opening displacement series to complete abnormality diagnosis, it has a good prospect for practical applications.展开更多
The hot rolling experiment of AZ31 magnesium alloy was carried out by laying anoverlay mold at the initial temperature of 400℃.According to the Mizushima automatic plan view pattern control system(MAS)rolling theory ...The hot rolling experiment of AZ31 magnesium alloy was carried out by laying anoverlay mold at the initial temperature of 400℃.According to the Mizushima automatic plan view pattern control system(MAS)rolling theory and the cross rolling process,different reductions in the middle and edges of the magnesium alloy were realized,and the influence of the regional controlled reduction rolling on the edge cracks and microstructure gradient of the magnesium alloy were analyzed.It is shown that this rolling approach has reduced the maximum edge crack depth of the rolled piece by 56.85%,and there is a weakening tendency in the base surface texture of the strip edge,the base surface texture density drops from 23.97 to 17.48 after ordinary flat rolling.It exhibits basal texture gradients from the edge to the middle of the sheet along the RD direction,which reflected the uneven deformation of the sheets.It is suitable for the processing of metal molds that require large edge reductions such as mobile phone shells,and provided a theoretical basis for the variable thickness rolling of the magnesium alloy strip.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 51079046, 50909041, 50809025, 50879024)the National Science and Technology Support Plan (Grant Nos. 2008BAB29B03, 2008BAB29B06)+7 种基金the Special Fund of State Key Laboratory of China (Grant Nos. 2009586012, 2010585212)the Fundamental Research Funds for the Central Universities (Grant Nos. 2009B08514, 2010B20414, 2010B14114)China Hydropower Engineering Consulting Group Co. Science and Technology Support Project (Grant No. CHC-KJ-2007-02)Jiangsu Province "333 High-Level Personnel Training Project" (Grant No. 2017-B08037)the Natural Science Foundation of Hohai University (Grant No. 2008426811)Graduate Innovation Program of Universities in Jiangsu Province (Grant No. CX09B_163Z)the Science Foundation for The Excellent Youth Scholars of Ministry of Education of China (Grant No. 20070294023)Dominant Discipline Construction Program Funded Projects of Universities in Jiangsu Province
文摘A method of the fuzzy cross-correlation factor exponent in dynamics is researched and proposed to diagnose abnormality of cracks in the concrete dam. Moreover, the Logistic time series changing from period-doubling bifurcation to chaos is tested first using this method. Results indicate that it can distinguish inherent dynamics of time series and can detect mutations. Considering that cracks in the concrete dam constitute an open, dissipative and complex nonlinear dynamical system, a typical crack on the downstream face of a concrete gravity arch dam is analyzed with the proposed method. Two distinct mutations are discovered to indicate that the abnormality diagnosis of cracks in the concrete dam is achieved dynamically through this method. Furthermore, because it can be directly utilized in the measured crack opening displacement series to complete abnormality diagnosis, it has a good prospect for practical applications.
基金Project(52005358)supported by the National Natural Science Foundation of ChinaProjects(201901D111243,201901D111241)supported by the Natural Science Foundation of Shanxi Province,ChinaProject(2019-KF-25-05)supported by the Natural Science Foundation of Liaoning Province,China。
文摘The hot rolling experiment of AZ31 magnesium alloy was carried out by laying anoverlay mold at the initial temperature of 400℃.According to the Mizushima automatic plan view pattern control system(MAS)rolling theory and the cross rolling process,different reductions in the middle and edges of the magnesium alloy were realized,and the influence of the regional controlled reduction rolling on the edge cracks and microstructure gradient of the magnesium alloy were analyzed.It is shown that this rolling approach has reduced the maximum edge crack depth of the rolled piece by 56.85%,and there is a weakening tendency in the base surface texture of the strip edge,the base surface texture density drops from 23.97 to 17.48 after ordinary flat rolling.It exhibits basal texture gradients from the edge to the middle of the sheet along the RD direction,which reflected the uneven deformation of the sheets.It is suitable for the processing of metal molds that require large edge reductions such as mobile phone shells,and provided a theoretical basis for the variable thickness rolling of the magnesium alloy strip.
