JIPKIC 结构设计原理 The principle of structure design The main content of this chapter Characteristics of use of reinforced concrete beam during the calculation. The concept of transformed section and the geometric characteristics. The stress state of reinforced concrete short-term checking. Flexural members of the cracks and the maximum width of crack. Deformation of flexural members. Durability of concrete structures.  Characteristics of use of reinforced concrete beam during the calculation.  The concept of transformed section and the geometric characteristics.  The stress state of reinforced concrete short-term checking.  Flexural members of the cracks and the maximum width of crack.  Deformation of flexural members.  Durability of concrete structures. The main content of this chapter ：