Life and damage contradiction - Hyperlife fatigue

Jegan cae
Jegan cae New Altair Community Member
edited March 7 in Community Q&A

Hello,

I was performing Random response fatigue analysis with PSD data (1 direction).

First 1G base excitation was done in Optistruct to get the Transfer function (Modal based FRF in 1 direction).

The H3D FRF results and PSD (Exposure time of 1 hour) were given as an event. Stress life approach was chosen.

The problem got solved and there was Damage (>1) on a particular component as expected.

But when I look at the Life contour plot, the cycles were very high numbers (more than 1 million).

My question is, if the Damage is higher than one, then the life should be some limited number of cycles, right?

How to comprehend this result?

Request support from Altair community.

Thanks,

Jegan

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Answers

  • Omar_NDIAYE
    Omar_NDIAYE
    Altair Employee
    edited March 7

    Hello Jegan,

    Have you look at the same element for damage and life ?
    In fact, the Life is the reciprocal of the Damage. So if the Damage > 1.0, then the Life should be less than 1.0.

    I would suggest to use the Callouts feature to mark a particular element and check the value of Life and Damage for that element.

    I hope this helps.

    Best regards,

    Omar.

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