Goodman/Soderberg/Gerber API

Returns the fatigue factor of safety under combined mean and alternating stress by the Goodman, Soderberg (linear) and Gerber (parabolic) criteria, plus a first-cycle yield check. Answers 'Is my mean+alternating stress combination safe for infinite life?', 'Which mean-stress criterion governs?'.

Price$0.06per request

MethodPOST

Route/v1/engineering/mean-stress-fatigue

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

fatiguegoodmansoderberggerbermean-stressendurance-limitsafety-factormachine-design

API URLhttps://x402.hexl.dev/v1/engineering/mean-stress-fatigue

Integration docs

Example request

{
  "alternatingStressMpa": 100,
  "meanStressMpa": 50,
  "enduranceLimitMpa": 200,
  "ultimateStrengthMpa": 400,
  "yieldStrengthMpa": 300
}

Example response

{
  "goodmanFactorOfSafety": 1.6,
  "soderbergFactorOfSafety": 1.5,
  "gerberFactorOfSafety": 1.8885,
  "firstCycleYieldFactor": 2,
  "governingCriterion": "Soderberg most conservative, Gerber least; Goodman is the common design line.",
  "formula": "Goodman σa/Se+σm/Sut=1/n; Soderberg σa/Se+σm/Sy=1/n; Gerber σa/Se+(σm/Sut)²=1/n",
  "interpretation": "Goodman FoS ≥ 1 — predicted infinite life under this mean+alternating combination."
}

Input schema

{
  "type": "object",
  "required": [
    "alternatingStressMpa",
    "meanStressMpa",
    "enduranceLimitMpa",
    "ultimateStrengthMpa"
  ],
  "properties": {
    "alternatingStressMpa": {
      "type": "number",
      "examples": [
        100
      ]
    },
    "meanStressMpa": {
      "type": "number",
      "examples": [
        50
      ]
    },
    "enduranceLimitMpa": {
      "type": "number",
      "examples": [
        200
      ]
    },
    "ultimateStrengthMpa": {
      "type": "number",
      "examples": [
        400
      ]
    },
    "yieldStrengthMpa": {
      "type": "number",
      "examples": [
        300
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}