老化阶段 meaning in English

ageing step
aging step

The author holds that enterprise life cycle has three phases : growing phase , mature phase , regenerating and aging phase
文章认为企业生命周期有三个阶段：成长阶段、成熟阶段、再生与老化阶段。
Structural full longevity processes basically could be divided into three main phase : construction phase , operational phase and aging phase
结构的全寿命过程基本上可以划分为三个主要阶段，即建造阶段、使用阶段和老化阶段。
As service life of buildings approaching to projected life , or their structures entering aging stage , people are gradually concerned about the health status of the structure and security estimation
摘要随着我国部分房屋建筑使用年限接近设计期限，或者说结构进入老化阶段，结构的健康状况和安全性评估逐步引起人们的关注。
Upon the investigations , the mean failure rate of the structure is higher during construction phase and aging phase . whereas , in the field of structure reliability , less studies are focused on the aging phase currently
据调查，结构在全寿命过程中平均失效率较高的是建造阶段和老化阶段，而老化阶段也是当前结构可靠度领域研究较少的阶段。