IMPROVED STRUCTURAL FATIGUE ANALYSIS USING FEM: DEVELOPMENT OF API SCRIPTS FOR STRESS RANGE CALCULATION

Abstract

: This paper presents an improved procedure for performing structural fatigue analysis using the finite element method (FEM). Numerical analyses were conducted for two typical structural load cases using Femap with NX Nastran software. To automate the fatigue stress range calculations, two custom API scripts were developed. The fatigue stress range was determined as the difference between the stress responses of the two load cases. First API script calculates the stress range based on the principal stresses, while second script uses the Von Mises equivalent stress criterion. The resulting stress ranges from both methods were compared, and their deviations were analysed. By automating the otherwise time-intensive task of calculating stress range vectors, these API scripts significantly reduce the required engineering time and probability of error. The results of the fatigue analysis confirm that these API tools can effectively improve the process and save engineering time.