Under JT/T 617.6 and GB 18564.1, why are tank vehicles transporting liquid dangerous goods generally restricted from operating with a filling degree (充装率) between 20% and 80% unless the tank is compartmentalized or equipped with surge baffles?

1. Liquid sloshing (液体晃动) within a partially filled tank generates severe dynamic wave forces that destabilize vehicle handling and cause sudden rollover during braking or cornering
2. Liquids expand into dangerous gaseous bubbles only when filled to exactly 50%
3. Tanks with 50% filling automatically trigger the engine speed limiter to drop to 10 km/h
4. Partial filling creates a vacuum that causes the entire steel chassis to warp permanently