OldDuffus
Structural
- May 20, 2021
- 2
thread794-427944
This post is in reference to the thread 794-427944 which was once active in 2017. At that time, Pauletta asked the question where the 0.6 term came from in the pressure vessel minimum required thickness equation of, I believe, ASME, Sect VIII. Most of my experience was with ASME Sect 1 (Power Boilers), I worked for the B&W company. I knew Jim Farr personally at work, who is mentioned in the original thread. The thread included answers to her question that summarized that the factor of 0.6 and historic data that shows other possible constants ranging from 0.5 to 0.6. The general conclusion was that these factors in the thin-wall equation are usually empirically determined and are included to amplify the thickness required for a pressure vessel to address the non-uniform circumferential stress distribution seen in thicker-walled vessels as modelled by the Lame' formula.
My question is: Does anyone have the paper or a short-cut to it that documents an ASME study made, I think, in 1943 on the variations to the thin wall pressure vessel equation? It reviewed the derivations of several thickness equations and their authors which included the one with 0.6 which is H.C. Boardman's equation. The paper may have been part of the minutes of an ASME committee or conference. My take is that these early formulas can be thought of as curve fits using a simple formula involving multiplication and division, suitable for slide rule use. I don't know if they were fitting the classical Lame' formula for thick-walled vessels or attempting to fit empirical data.
This post is in reference to the thread 794-427944 which was once active in 2017. At that time, Pauletta asked the question where the 0.6 term came from in the pressure vessel minimum required thickness equation of, I believe, ASME, Sect VIII. Most of my experience was with ASME Sect 1 (Power Boilers), I worked for the B&W company. I knew Jim Farr personally at work, who is mentioned in the original thread. The thread included answers to her question that summarized that the factor of 0.6 and historic data that shows other possible constants ranging from 0.5 to 0.6. The general conclusion was that these factors in the thin-wall equation are usually empirically determined and are included to amplify the thickness required for a pressure vessel to address the non-uniform circumferential stress distribution seen in thicker-walled vessels as modelled by the Lame' formula.
My question is: Does anyone have the paper or a short-cut to it that documents an ASME study made, I think, in 1943 on the variations to the thin wall pressure vessel equation? It reviewed the derivations of several thickness equations and their authors which included the one with 0.6 which is H.C. Boardman's equation. The paper may have been part of the minutes of an ASME committee or conference. My take is that these early formulas can be thought of as curve fits using a simple formula involving multiplication and division, suitable for slide rule use. I don't know if they were fitting the classical Lame' formula for thick-walled vessels or attempting to fit empirical data.
