Session: CS-01-02 Structural Integrity of Pressure Components-2

Paper Number: 154615

154615 - A Comparative Study on Estimating Fatigue Life Using the Asme sec.viii div.2 Code Methodology ,In Comparison to Other International Standards Such as En-13445 , Ad 2000 Markblatt, and Pd 5500. 

Abstract: 

Nowadays, pressure equipment is often subjected to complex loading conditions, with cyclic loading being one of the most significant. When equipment is exposed to cyclic loading, it becomes essential to evaluate its fatigue life. Fatigue life assessment is a key factor in ensuring the safe and long-term operation of pressure equipment under these conditions.

Design codes typically offer "screening tests" to determine if a full fatigue analysis can be avoided, usually based on the expected number of stress cycles during the equipment’s design life. In addition, they provide simplified fatigue analysis methods that rely on assumptions about loading conditions and fatigue resistance, as well as detailed fatigue analysis procedures for more comprehensive evaluations.

The ASME fatigue rules, developed in the early 1960s, are based on the concept that fatigue life can be estimated using S-N curves for the relevant material, derived from fatigue tests on small, polished specimens, with various correction factors applied. In contrast, other codes such as EN-13445,PD5500 & AD 2000 Merkblatt, place greater emphasis on assessing fatigue in welded joints.

This paper aims to compare the fatigue life estimation approaches of several international codes by analysing a random nozzle-to-shell geometry. The comparison will focus on calculating the damage factor and fatigue life leading to a final conclusion based on the results.

Presenting Author: Shyam Gopalakrishnan LRQA Inspection Services India LLP

Presenting Author Biography: Technical review team leader

Authors:

Sujay Pathre LRQA Inspection Services India LLP
Shyam Gopalakrishnan LRQA Inspection Services India LLP
Mohammad Abdul Qadeer LRQA Inspection Services India LLP
Akshay Chalvade LRQA Inspection Services India LLP
Ameya Mathkar Thyssenkrupp Uhde India Pvt.Ltd