Rigidity influence of round attachment without opening

For safety and accuracy,the influence of the rigidity of hollow attachment on calculation should be considered.Equivalent stresses about fatigue analysis from WRC107 and EN13445 were compared with those from the finite element method,under three thickness configurations of round attachment,that half,equal,double of shell thickness.Results show that in key point Au defined by WRC107 stress decreases while attachment thickness increases,and that in key point C stress increases while attachment thickness increases.When the thickness of attachment equals to that of the shell,the equivalent stress of WRC107 in C comes closest to FEM.EN13445 overestimates the stresses and it is less influenced by the thickness of attachment.As a conclusion,round attachment thickness should be considered when using WRC107.