Notch-Type Division for Modified Field Intensity Fatigue Prediction
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Solution Overview
Problem
Conventional field intensity approach models face significant computational challenges in predicting the fatigue life of notched components due to local stress concentration, making it difficult to define the fatigue failure zone accurately.
Innovation Solution
A modified field intensity approach based on notch type division, involving elastic-plastic finite element analysis, stress-strain distribution, notch type classification, and simplified one-dimensional models to predict fatigue life, using S-N curves for smooth materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional field intensity approach model is used to predict fatigue life of notched components, then prediction can be performed, but calculation complexity increases significantly and fatigue failure zone definition becomes difficult
Solution Approach 1:
The patent segments the complex stress distribution problem by dividing the notch into three distinct types (sharp notch, moderate notch, passivation notch) based on stress gradient characteristics. Each notch type is associated with a specific field diameter definition and simplified calculation model, transforming the single complex prediction problem into multiple simpler sub-problems that can be handled systematically.
Solution Approach 2:
The patent applies local quality by defining different field diameters and correction parameters for different notch types. Instead of using a universal approach, the method tailors the field intensity calculation to the specific local characteristics of each notch type, with each type having its own designated field diameter (e.g., distance from notch root to stagnation point for sharp notches) and corresponding correction parameter ξ(Ω).
Data Source
AI summary
The disclosure relates to a technical field of engineering metals, in particular to a fatigue life prediction method based on notch type division by a modified field intensity approach, including: S1, carrying out elastic-plastic finite element analysis on a notched component to be analyzed, obtaining a stress-strain distribution, extracting a stress distribution on the most dangerous path of the notched component, and calculating a corresponding relative stress gradient; S2, dividing notch types according to an obtained relative stress gradient; S3, defining a field diameter of a corresponding notch according to different stagnation point positions; S4, according to a divided field diameter, bringing the field diameter divided into simplified one-dimensional field intensity approach models, and calculating a corresponding equivalent stress according to the divided field diameter; and S5, combining an S-N curve of a smooth material, and predicting the fatigue life of the notched component according to a calculated equivalent stress.