life expectancy of design

• 设计使用年限

life expectancy of design的用法和样例：

例句

1. This paper introduces the design working life and durability design for structures in China and abroad, esp.
   介绍国内外结构尤其是英国海工结构的设计使用年限及耐久性设计概况。
2. The durability design of the concrete structure should be done according to the environment types and the designed serviceable life.
   混凝土结构的耐久性设计应根据环境类别和设计使用年限进行设计。