对于结构塑性动力响应问题,一般的是先从静态极限分析的完全解出发,假设其速度场,然后根据各种条件进行求解。本文以圆板塑性动力响应问题为例,给出一种不同的求解方法,即联合运用拉普拉斯变换和加权余量法进行分析和求解。先通过拉普...对于结构塑性动力响应问题,一般的是先从静态极限分析的完全解出发,假设其速度场,然后根据各种条件进行求解。本文以圆板塑性动力响应问题为例,给出一种不同的求解方法,即联合运用拉普拉斯变换和加权余量法进行分析和求解。先通过拉普拉斯变换将薄板的动力问题转化为静力问题,然后根据弯矩 M 和挠度 w 的边界条件分别假设试函数,再应用加权余量法进行求解。展开更多
The hot deformation simulation of a ZK60 magnesiuln alloy at different temperatures from 373 to 673 K and different strain rates of 0.1, 0.01 and 0.002 s^-1 was studied by using the Gleebe-1500 simulator. The plastic ...The hot deformation simulation of a ZK60 magnesiuln alloy at different temperatures from 373 to 673 K and different strain rates of 0.1, 0.01 and 0.002 s^-1 was studied by using the Gleebe-1500 simulator. The plastic deformation behavior was measured and the deformation activation energy was calculated. The microstructures of ZK60 magnesium alloy with an addition of neodymium during the deformation process were observed by using Polyvar-MET optical microscope and Tecnai G^2 20 TEM. The results show that the working hardening, the dynamic recovery and the dynamic recrystallization occur during the plastic deformation process at different temperatures and strain rates. The dynamic recrystallization starts when the temperature is over 473 K and the DRX grain size after hot deformation is only 5-10 μm. So the refined grains improve both the tensile strength and the elongation of alloys at room temperature. Neodymium is added into the alloy and a precipitate phase Mg12Nd that impedes the movement of dislocations is formed, which benefits to increasing mechanical properties of ZK60 magnesium alloy.展开更多
文摘对于结构塑性动力响应问题,一般的是先从静态极限分析的完全解出发,假设其速度场,然后根据各种条件进行求解。本文以圆板塑性动力响应问题为例,给出一种不同的求解方法,即联合运用拉普拉斯变换和加权余量法进行分析和求解。先通过拉普拉斯变换将薄板的动力问题转化为静力问题,然后根据弯矩 M 和挠度 w 的边界条件分别假设试函数,再应用加权余量法进行求解。
基金Project(2006BAE04B02-3)supported by the National Key Program of 11th Five-Year Plan of China
文摘The hot deformation simulation of a ZK60 magnesiuln alloy at different temperatures from 373 to 673 K and different strain rates of 0.1, 0.01 and 0.002 s^-1 was studied by using the Gleebe-1500 simulator. The plastic deformation behavior was measured and the deformation activation energy was calculated. The microstructures of ZK60 magnesium alloy with an addition of neodymium during the deformation process were observed by using Polyvar-MET optical microscope and Tecnai G^2 20 TEM. The results show that the working hardening, the dynamic recovery and the dynamic recrystallization occur during the plastic deformation process at different temperatures and strain rates. The dynamic recrystallization starts when the temperature is over 473 K and the DRX grain size after hot deformation is only 5-10 μm. So the refined grains improve both the tensile strength and the elongation of alloys at room temperature. Neodymium is added into the alloy and a precipitate phase Mg12Nd that impedes the movement of dislocations is formed, which benefits to increasing mechanical properties of ZK60 magnesium alloy.
