Discussion on the Implementation of the Primary Structure Method in Design by Analysis

The implementation of the primary structure method in design by analysis of pressure vessel is discussed. With two examples of axisymmetric structure of pressure vessel, flat head-cylindrical shell joint and flange-ellipsoidal head joint, the primary structure is constructed according to the principle of this method with ANSYS. By comparing the stress intensity and deformation of the primary structure with that of the original structure, the primary and secondary stress along the stress classification line can be clearly distinguished by using the primary structure method. It has great application value in dealing with stress classification in the elastic stress analysis method. The results also show that a variety of reasonable primary structures can be constructed based on the same original structure, and the primary structure method has some flexibility.