Study On Dynamic Buckling Of Cylindrical Shell Subjected To Axial Impact Of Rigid Mass Based On Energy Method

As the basic element of the structure,the cylindrical shell is widely used in practical life and various engineering practices.For example,shell structure has been utilized in kinds of aircraft,weapons and ships.Scholars have paid great attention to the study of structural buckling.At present,the research on static buckling is sufficient,but the research on dynamic buckling is still full of challenges.Based on this,the dynamic buckling of cylindrical shell subjected to axial impact of rigid mass is studied in this paper.The specific research content is as follows:1.The research status of cylindrical shells is reviewed.2.Based on the energy method and considering the stress wave effect,the buckling of cylindrical shell subjected to a rigid mass is studied.Substituting the Lagrange function and the trial function satisfied the boundary condition into the second Lagrange equation,the second-order linear partial differential equation is obtained.The analytical expression of the critical buckling speed of a rigid mass impacting cylindrical shell is derived by analyzing the properties of the equations.3.The influence of the critical length,impact mass,axial mode number,circumferential mode number and diameter-thickness ratio on elastic and elastoplastic buckling are discussed by analyzing the examples.The results show that:When the number of modes is different,the v_cr decreases with the increase of the l_cr,indicating that the stress wave effect has a significant effect on the dynamic buckling.When the l₀ is the same,the initial impact kinetic energy decreases as the number of modes increases,indicating initial kinetic energy has a significant effect on buckling.When m is different,the curves almost coincide,which is different from the influence of n on buckling.When k is different,the v_cr increases as the k decreases.It shows that the higher k is,the easier the buckling of the cylindrical shell can be excited by high-speed impact.When the boundary conditions are different,the v_cr of the clamped-fixed cylindrical shell is greater than the v_cr of the hinge-solid cylindrical shell and greater than the v_cr of the free-fixed support,indicating that the boundary conditions have a significant effect on buckling.Under the same impact load,cylindrical shells with free-fixed boundary conditions are more likely to buckle.The initial impact velocity of the elastoplastic buckling is greater than the initial velocity of the elastic buckling,which indicates that the initial kinetic energy has a significant effect on buckling.