Fatigue life prediction method and device based on weighted average maximum shear stress plane

A technology of fatigue life prediction and shear stress, which is applied in the direction of measuring devices, testing material strength by applying stable shear force, testing of mechanical components, etc., can solve problems such as no better solution

CN111624116AActive Publication Date: 2020-09-04TSINGHUA UNIV +1
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2020-09-04

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Abstract

The invention provides a fatigue life prediction method and device based on a weighted average maximum shear stress plane. The method relates to the field of multi-axis fatigue strength theories, andcomprises the following steps: (1) synthesizing multi-axis variable-amplitude load processes into an equivalent stress process through a von Mises equivalent stress formula, and performing cyclic counting on the von Mises equivalent stress process through a Wang-Brown multi-axis cyclic counting method; (2) taking the proposed weighted average maximum shear stress plane as a critical plane under ahigh-cycle multi-axis variable-amplitude load; (3) calculating a fatigue damage parameter on the critical surface in each repeating by counting; (4) carrying out fatigue damage calculation by adoptinga Zhang-Shang model; and (5) accumulating damage calculated in each repeating by adopting a Miner linear accumulation rule, and finally calculating the fatigue life. The weight function proposed in the method can consider the main fatigue damage mechanism under multi-axis loading. The life prediction result shows that the life prediction method can better predict the fatigue life under multi-axisconstant amplitude and variable amplitude loading.
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Description

technical field

[0001] The invention relates to the field of multiaxial fatigue strength theory, in particular to a fatigue life prediction method and device based on a weighted average maximum shear stress plane. Background technique

[0002] The lithography machine is the core equipment for manufacturing large-scale integrated circuits. The electromechanical system of the lithography machine contains a large number of components, and many components are subjected to complex multi-axis random loads during operation. Under the action of multi-axial random loads, mechanical parts will experience sudden fatigue fracture after a period of operation, resulting in huge economic and property losses. The traditional uniaxial fatigue strength theory can no longer meet the design requirements of strength and fatigue life of actual engineering components. Therefore, in recent years, more attention has been paid to multiaxial fatigue research that is more in line with engineering reali...

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Embodiment Construction

[0066] Embodiments of the high cycle multiaxial fatigue life prediction method based on the weighted average maximum shear stress plane according to the present invention will be described below with reference to the accompanying drawings. Those skilled in the art would recognize that the described embodiments can be modified in various ways or combinations thereof without departing from the spirit and scope of the invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims. Also, in this specification, the drawings are not drawn to scale, and like reference numerals denote like parts.

[0067] The high-cycle multiaxial fatigue life prediction method based on the weighted average maximum shear stress plane includes the following steps:

[0068] Step 1): Obtain the load history of the notched parts, such as Figure 2a Shown, F N is the loaded axial force, M T For loading to torque, the load history of the...