It indicates that the key to increase service life of component lies in shortening final crack length ofmicro-short-crack expansion and increasing physics-short-crack threshold demension.

• 建立了疲劳寿命估算模式,阐述了疲劳寿命的影响因素,指出提高构件使用寿命的关键在于缩短微观短裂纹扩展的终止裂纹长度,增大物理短裂纹扩展的门槛裂纹尺寸。