Component welding spot random vibration fatigue life distribution prediction method based on rain flow method

Abstract

The invention provides a component welding spot random vibration fatigue life distribution prediction method based on a rain flow method. The method comprises the following steps: firstly, acquiring alocal power spectral density (PSD) response curve of a component welding spot under the action of a random vibration environment by adopting a finite element simulation technology; and converting thepower spectral density (PSD) response curve into a plurality of different stress-time response curves in a time domain by using a Monte Carlo method and a time domain simulation method (an inverse Fourier transform method, a trigonometric series method and the like), and calculating fatigue life distribution of component welding spots by using a rain flow method. According to the method, the finite element simulation analysis result is efficiently converted into the stress-time response curve in the time domain, the recording process of long-time response signals is avoided, the calculation workload of fatigue life is reduced, and a time domain analysis interface is provided for the finite element simulation technology. Meanwhile, the invention provides the component welding spot random vibration fatigue life distribution prediction method, and the confidence coefficient of a fatigue life prediction result is improved.

Description

technical field [0001] The invention relates to the technical field of reliability of electronic components, in particular to a method for predicting the random vibration fatigue life distribution of solder joints of components. First, the finite element simulation technology is used to obtain the local power spectral density (PSD) response curve of the component solder joint under the random vibration environment, and then the Monte Carlo method and the time domain simulation method (inverse Fourier transform method, trigonometric series method, etc.) to convert the power spectral density (PSD) response curve into a stress-time response curve in the time domain, and then use the rainflow method to predict the fatigue life distribution of component solder joints. Background technique [0002] When the working environment of electronic products is harsh, or the interconnection of internal devices is complex, random vibration often becomes the main cause of electronic product ...

AI Technical Summary

Problems solved by technology

[0004] The existing time-domain analysis method needs to record the random vibration response signal for a long enough time, the recording method is complicated, the test period is long, and it is difficult to combine with the finite element analysis method commonly used in engineering, and the engineering applicability is poor

The accuracy of the prediction results of the existing frequency domain analysis method is insufficient, and the results are quite different in the face of random vibration loads with different stress amplitude ratios and different bandwidths

Although the frequency domain analysis method is closely related to the finite element simulation analysis, only one fatigue life prediction result can be obtained in one simulation experiment through the frequency domain analysis method alone, and a reasonable distribution of the predicted fatigue life cannot be obtained, and the reliability of the result is low.

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