Analysis of Stiffened Penstock External Pressure Stability Based on Immune Algorithm and Neural Network

Table 6

Computational results of various calculation methods.

Shell thickness	Mises method		Semianalytical finite; element method				Lai-Fan method		Proposed method; in this paper
			Stiffening ring as; simple supported		Stiffening ring  as; fixed supported
	𝑃cr; MPa	𝐾	𝑃cr; MPa	𝐾	𝑃cr; MPa	𝐾	𝑃cr; MPa	𝐾	𝑃cr; MPa	𝐾
20	1.529	1.91	0.859	1.07	1.595	1.99	2.716	3.40	1.579	1.97
22	1.965	2.46	1.144	1.43	2.123	2.65	3.462	4.33	2.273	2.84
25	2.690	3.36	1.678	2.10	3.115	3.89	4.795	5.99	2.916	3.64
27	3.266	4.08	2.114	2.64	3.924	4.91	5.846	7.31	3.784	4.73
29	3.926	4.91	2.619	3.27	4.862	6.08	7.031	8.79	4.592	5.74