Thermal Stress Field Guide | Cassandra Johnson

CORE DEFINITIONS

The "Golden Seam" is a myth. Survival is defined by staying within the elastic limit of your material during phase transition.

Parameter	Symbol	Definition	Critical Value
Glass Transition Temp	T_g	Threshold where amorphous solid becomes viscous/rubbery	~65°C (Starch)
Fracture Toughness	K_IC	Stress intensity at catastrophic crack propagation	Variable (See Failure)
Thermal Conductivity	k	Rate of heat transfer through matrix	0.5 W/(m·K)

FAILURE MODES

WARNING: Exceeding K_IC results in irreversible structural loss. No amount of "narrative" repairs a fractured load path.

Mode 1: Thermal Shock
ΔT exceeds cooling capacity. Outer skin vitrifies while core remains fluid. Result: Expansion mismatch → shear failure.

Mode 2: Viscoelastic Creep
Sustained T > T_g causes slow deformation under constant load. Result: Sagging geometry.

Mode 3: Moisture Flash
Internal water reaches boiling point before vapor pressure equalizes. Result: Explosive delamination.

OPERATIONAL PROTOCOL

PREHEAT: Ramp rate ≤ 2°C/min until T = T_g - 10°C.
HOLD: Maintain uniformity across the matrix. Verify thermal equilibrium.
RAMP: Increase to target temp. Monitor surface tension.
COOL: Controlled descent. Rate must not exceed thermal diffusion speed of core.

σ_thermal = E · α · ΔT
// Where E = Young's Modulus, α = Coefficient of Thermal Expansion

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