不确定初始几何缺陷杆动态屈曲失效分析

Dynamic buckling failure analysis of rod with uncertain initial geometrical imperfection

由初始几何缺陷所引起的结构屈曲载荷降低最高可达70%.由于制造误差等原因使得结构初始几何缺陷往往具有不确定性,而这种不确定性又必然会导致结构屈曲荷载与动态屈曲响应的不确定性.研究了动载作用下含有不确定初始几何缺陷杆的动态屈曲失效问题.基于积分挠度定义了动态屈曲安全因子.采用区间分析方法和凸模型方法,给出了具有不确定初始几何缺陷杆的基于积分位移的动态屈曲安全因子的最不利估计,其结果为判断具有不确定初始几何缺陷杆结构的动态屈曲失效分析提供了重要依据.

It can be found from some data that the buckling load of structure may decrease by 70 percent due to the existence of initial geometric imperfection.The initial geometric imperfection may be uncertain due to the manufacture errors and so on,so this will lead to the uncertainty of the buckling load or the dynamic buckling response of structure.The problem of dynamic buckling failure of rod with uncertain initial geometrical imperfection under the axial dynamic loading was studied.The safety factor was defined based on the integral deflection.The uncertain initial geometrical imperfection was described by interval analysis and convex models respectively,and then the least favorable estimation on the dynamic buckling safety factor of rod was evaluated based on the integral displacements.The results are significant for judging the dynamic buckling failure analysis of rod with uncertain initial geometrical imperfection.