AISC/AWS Fatigue Stress Category Checker Calculator

Determine fatigue stress category and allowable stress range for welded details per AISC 360 Appendix 3 and AWS D1.1

Input Parameters

Results

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Allowable Stress Range (FSR)
ksi
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Actual Stress Range
ksi
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Threshold (FTH)
ksi
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Pass/Fail
Note: Fatigue categories per AISC Table A-3.1. Category A (base metal) has highest fatigue resistance. Category E' (thick fillet weld ends) has lowest. Details below FTH have theoretically infinite life.

Reference

AISC 360 Appendix 3 / AWS D1.1 Fatigue Provisions Allowable stress range: FSR = (Cf/N)^(1/3) >= FTH Cf = fatigue constant (Table A-3.1) FTH = threshold stress range (infinite life) Categories A through E' based on weld detail type N = number of stress range cycles in design life