Abstract: Based on the theory of fatigue strength,a parameter of effective equivalent stress amplitude is introduced.The optimum overstrain extent of autofrettaged thick-walled cylinders has been studied with elasto－plasticity theory and finite－element method(FEM)－In order to get the longest fatigue life.the effective equivalent stress amplitude of inner surface should be the smallest.and be equal or quite approach to that of outer surface.

Key words: prestress, high pressure vessel, fatigue strength, residual stress, stress analysis, strain, yield stress

摘要： 基于疲劳强度理论,引入等效相当应力幅参量,对高压与超高压设备自增强处理时的最佳超应变度进行了理论分析与有限元计算.最佳的超应变度应使设备内表面有最低且内外壁面尽可能接近的等效相当应力幅,此时设备将有最长的疲劳寿命.

关键词: 预应力, 高压容器, 疲劳强度, 残余应力, 应力分析, 应变, 屈服应力