김경종
57 lines
2.5 KiB
Markdown
57 lines
2.5 KiB
Markdown
---
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type: concept
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title: "Midas NFX Fatigue Analysis"
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created: 2026-06-02
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updated: 2026-06-02
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address: c-000181
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aliases:
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- NFX fatigue analysis
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tags:
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- concept
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- finite-element-method
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- midas-nfx
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- fatigue
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- verification
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status: current
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related:
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- "[[Midas-NFX-Analysis-Manual|Midas NFX Analysis Manual]]"
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- "[[midas NFX]]"
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- "[[Finite Element Modeling and Convergence Checks]]"
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- "[[Abaqus Progressive Damage and Failure]]"
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- "[[Midas FEA Fatigue Analysis]]"
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sources:
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- "[[Midas-NFX-Analysis-Manual|Midas NFX Analysis Manual]]"
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---
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# Midas NFX Fatigue Analysis
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## Definition
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NFX fatigue analysis estimates fatigue damage and life from finite element stress or strain histories. The manual covers stress-life, strain-life, and random vibration fatigue approaches.
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## Stress-Life Method
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The stress-life method uses S-N curves and is positioned for relatively low stress levels where elastic behavior dominates. The manual describes stress amplitude, mean stress, rainflow counting for variable-amplitude histories, S-N curve correction factors, Miner cumulative damage, and life as inverse damage.
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## Mean-Stress Corrections
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The source includes Goodman, Gerber, Soderberg, Morrow, and Smith-Watson-Topper style mean-stress correction ideas. This matters for solver verification because identical FE stress histories can produce different fatigue lives depending on correction method.
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## Strain-Life Method
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The strain-life method is positioned for higher stress/strain concentration regions where plastic strain can control life. The manual includes elastic/plastic strain decomposition, cyclic strength/hardening parameters, and Neuber-rule based recovery from linear elastic results.
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## Random Vibration Fatigue
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For complex load histories, the manual also treats frequency-domain random vibration fatigue. That workflow connects modal/frequency response outputs to fatigue damage rather than relying on explicit time histories.
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## Solver Development Use
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For a custom solver, fatigue is primarily a postprocessing harness problem. The FE solver must first produce trusted stress/strain histories at documented locations; only then should rainflow counting, S-N/E-N interpolation, mean-stress correction, Miner damage, and random-response fatigue be tested.
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## Connections
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- [[Finite Element Modeling and Convergence Checks]] connects fatigue accuracy to stress recovery and mesh quality.
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- [[Abaqus Progressive Damage and Failure]] provides a broader damage/failure comparison.
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- [[Midas FEA Fatigue Analysis]] is the sibling MIDAS fatigue reference.
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