Method for predicting fatigue life of moving component

Abstract

The invention discloses a method for predicting the fatigue life of a moving component, which comprises the following steps of: simplifying the moving process of the moving component into a plurality of moving positions, finding out first failure points of the moving component at the moving positions through finite element analysis, and establishing a mapping relation between stress or strain of the first failure points and the fatigue life; and calculating to obtain the damage amount generated by the first failure point when the moving component is at each moving position, and calculating to obtain the fatigue life of the moving component by taking the fatigue damage amount of the first failure point at each moving position in one moving period as a basis. According to the method, the motion process of the motion component is simplified from a dynamics problem to a statics problem, the complexity of fatigue life prediction of the motion component is reduced, and the proposed method is suitable for the fatigue life prediction problem of any motion component and can also be applied to fatigue life prediction of parts with multi-working-condition characteristics in the field of mechanical engineering.

Description

technical field [0001] The invention belongs to the field of fatigue life of mechanical structures, in particular to a method for predicting fatigue life of moving components. Background technique [0002] Fatigue damage is one of the main failure modes of most parts and components in the field of construction machinery. According to statistics, about 50% to 90% of structural damage is caused by fatigue damage. How to accurately predict the fatigue life of parts in the design stage? Providing mechanical guidance for its design and optimization has become a key problem for structural engineers to solve urgently. At present, the methods for predicting the fatigue life of mechanical structural parts mainly include: nominal stress method, local stress-strain method, fracture mechanics method, etc. By establishing the mapping relationship between the stress, strain or crack of structural parts and fatigue life, a prediction model is given. . The above methods are often used for...

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Problems solved by technology

The above methods are often used in the life prediction of key bearing structures in construction machinery, but only for a single working condition of the structure

However, when the moving components move to different positions, they often receive different loads. Due to the constant change of the load, the existing methods cannot be applied to the fatigue life prediction of the moving components, and the cost of building a fatigue testing machine for the moving components is too high.

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