Numerical Simulation Of Dynamic Response Of Plane Strain Ring Under Transient Rotation

In the military industry,aerospace,power machinery and other engineering fields,impact dynamics due to high-speed collisions and transient loading are often encountered.Numerical simulation is an important method to analyze the impact dynamics problem.Domestic commonly used software such as ANSYS/LS-DYNA and ABAQUS is used as a numerical simulation tool,but attention is paid to the numerical simulation study of the self-programming program.On the other hand,for a long time,the impact dynamics have focused on the dynamic response problems caused by the translational impact or loading of the material?such as long rod axial collisions,flyer collisions,etc.?,and the dynamic response to rotational transient loading.Less research.At the same time,the Jaumann stress rate is of great significance in the calculation of the material constitutive model.It is related to the stress state and the rotation rate of the material.It is worth paying attention to the influence of the Jaumann stress rate on the rotational dynamics.Therefore,the main content of this paper is as follows:Based on the theory of nonlinear continuum mechanics,a two-dimensional plane dynamic finite element program was developed by using the dynamic finite element method.This program was used to simulate the long-axis axial collision problem.The program calculation results can be compared with the LS-DYNA calculation results.Compared to the LS-DYNA calculation results,the error of the diameter increase of the long rod impact end remains within 4.2%.The error of the impact platform is within xx,which explains the correctness of the program.The programmed two-dimensional plane dynamics finite element method was used to simulate the dynamic response of a plane-strain ring under transient conditions.For the aluminum ring with inner and outer radii of 2 cm and 4 cm,two types of initial and boundary conditions were set up for numerical simulation analysis.The first type of condition is given the initial angular velocity,the inner and outer boundaries of the ring remain free;the second type of condition is given the inner boundary or outer boundary angular velocity,the ring is initially stationary;the angular velocity is 10^-4 rad/?s and 2.0?10^-2 rad/?s.The results show that under the first type of conditions,the ring presents a phenomenon of radial and circumferential normal stress distribution and the shear stress is relatively weak;under the second type of conditions,the ring presents shear stress propagation and freedom.With the surface reflection effect,the radial and hoop normal stresses are relatively weak.The influence of Jaumann stress rate is studied in the long-pole collision and ring rotation dynamics examples.The results show that when the material rotation is not significant or the shear stress is not significant,the Jaumann stress rate has no obvious effect on the dynamic response.