updated bridge instruction

antantantant · antantantant · commit a0132520ddcb · 2026-03-18T14:23:35.000-07:00
diff --git a/mee342_bridge_design.md b/mee342_bridge_design.md
@@ -60,7 +60,7 @@ Use global axes with **+Z upward**.
   $
   q = 5.0\ \text{kN/m}^2 \quad \text{downward (−Z)}
   $
-- Fatigue load cycle: between "self-weight only" and "self-weight + q". Target is infinite life.
+- Fatigue load cycle: Use "zero-based loading" (between 0 and +q). Use equivalent stress as the "stress component" for life and safety factor calculation. Target is infinite life ($10^6$ cycles). Use fatigue strength factor (Kf) of 0.7.
 
 ## 6. Boundary conditions (supports)
 

Original file line number	Diff line number	Diff line change
`@@ -60,7 +60,7 @@ Use global axes with +Z upward.`
`60`	`60`	`$`
`61`	`61`	`q = 5.0\ \text{kN/m}^2 \quad \text{downward (−Z)}`
`62`	`62`	`$`
`63`		`-- Fatigue load cycle: between "self-weight only" and "self-weight + q". Target is infinite life.`
	`63`	`+- Fatigue load cycle: Use "zero-based loading" (between 0 and +q). Use equivalent stress as the "stress component" for life and safety factor calculation. Target is infinite life ($10^6$ cycles). Use fatigue strength factor (Kf) of 0.7.`
`64`	`64`
`65`	`65`	`## 6. Boundary conditions (supports)`
`66`	`66`