There is a design value called the design value of tensile strength of reinforcing steel bar, and there is a word called standard value. As you can imagine, these two values must be in order to ensure their safety, and come out of a numerical value, today I will tell you what these two are.

　　为了结构或者构件需要满足一定的强度保证率，原材料的强度不可能都是同一的强度，有的可能高点，有的低点，假如钢筋抗拉强度设计值是210兆帕的话，在100根钢筋里面，有95根强度在210以上，只有5根低于210，这就是满足95%保证率的要求。

　　For the sake of structure or component safety, the strength of raw materials can not be the same strength, some may be high, some low, if the design value of steel bar tensile strength is 210 MPa, 95 of the 100 steel bars have strength above 210, only 5 of them are below 210, which is to meet the requirement of 95% guarantee rate.

　　受拉钢筋设计时是按屈服强度设计都是以屈服强度为标准定的，屈服强度部分受拉和受压，屈服强度都是一样，比如Q235的钢筋，设计值就是235，标准值就是210，Q335的钢筋，设计值是335。标准值主要是计算承载力的，设计值使用来验算结构或构件的挠度和裂缝宽度的。

　　Tensile steel bars are designed according to yield strength. The yield strength is partly tension and compression, and the yield strength is the same. For example, Q235 steel bars, the design value is 235, the standard value is 210, Q335 steel bars, and the design value is 335. The standard value is mainly used to calculate the bearing capacity, and the design value is used to check the deflection and crack width of the structure or component.