Author : Hatem R. Wasmi, Mohammad Qasim Abdullah and Omar Ali Jassim

The ANSYS Fatigue Module has a wide range of features for performing calculations and presenting clear and accurate results. It is estimated that 50-90% of structural failure is due to fatigue, so there is a real need for quality fatigue design tools. However, at this time a fatigue tool is not available which provides both flexibility and usefulness comparable to other types of analysis tools. This is why many designers and analysts use “in-house” fatigue programs which cost much time and money to develop. It is hoped that those designers and analysts, were given a proper library of fatigue tools could quickly and accurately conduct a fatigue analysis suited to their needs. The objective of this work is to take the recommendations of the fatigue analysis in the body of the flange connection and it was considered as calculations of strain-life in ANSYS workbench. Three types of cycling loads were applied. Firstly, a fully reversed load was used, and the number of cycles to failure was found from 27334 minimum to 109 maximum for all the bodies, so we need wide ranges of safety factor as its found (0.25 min. to 15max.).Secondly, applying a zero based load, so the strain life cycles found to have the range (2.6*106 min. to 109max.) and safety factor range (0.5 to 15). Finally a ratio (min.stress / max. stress =0.5) fluctuating load were applied, then the number of cycles to failure were estimated and found to be equal to 109 for all the bodies and the range of safety factor is not varying too much as the other load but also it has a range (1 to 15).

Keyword: Flange Connection, ANSYS, Fatigue life and Fatigue sensitivity

Article published in International Journal of Current Engineering and Technology, Vol.6, No.4 (Aug-2016)