Life evaluation based on double linear damage rule for hydraulic pump piston fatigue

Double Linear Damage Rule (DLDR) is commonly used in analyzing cumulative fatigue damage. Compared with the Linear Damage Rule (LDR), the DLDR takes into account the long established fact that order of loading significantly affects the summation of the cycle ratios at failure. This paper presents a method for calculating the fatigue life, by analyzing the actual load spectrum of a certain type of hydraulic pump, the fatigue life of piston was obtained with DLDR, the ANSYS software was used to simulate the fatigue life according to the actual load distribution of the piston. The life of piston calculated by DLDR and that simulated by ANSYS conform with the actual situation. This paper shows that the DLDR theory applied to the fatigue life evaluation is feasible and effective, and is of great guiding significance to the development and optimization of aircraft components.