FINITE ELEMENT MESH SIZE IN FATIGUE LIFE EFFECT
Keywords: Fatigue life, Finite element analysis (FEA), Pipe elbow, Variable amplitude, loading(VAL), Tetrahedral element(Tet)
AbstractPipe elbows are consequential parts in a piping system. When a thin-wall elbow is
exposed to variable amplitude loading as internal cyclic pressure, piping elbows are
vulnerable to crack at the crown. This paper presents a technique to predict the fatigue
life of elbows with the application of variable amplitude loadings (VAL). For this goal,
the finite element analysis technique was being used for the modeling and simulation.
The fatigue life prognostication was carried out using the finite element based fatigue
analysis codes. Numerical life prognostication results of three types of elbows (135
and curved ) under VAL are presented and discussed. Varying elbows shows
different fatigue life behavior, the curved one gives better life. The two types of
elements (Tet4 and Tet10) were investigated with optimum mesh size to get the
maximum principle stress. The simulation results showed that more studies on the
piping elbows necessity to be performed in order to obtain more delicate fatigue life.