Model Predictions for Void Growth

Stage 1 The temperature is increased from 25°C (298 K) to 135°C (408 K) at 2°C/min, yielding a rise time of 55 min. The autoclave pressure is one atm. the pressure inside the vacuum bag is 0.1 atm and remains so throughout the entire cycle. 

Stage 3 The autoclave pressure is increased from one to 5.78 atm at a constant temperature of 135°C (408 K). 

Stage 4 The temperature continues to be held constant at 135°C (408 K) under a constant autoclave pressure of 5.78 atm for 105 min. 

Stage 5 The temperature is increased from 135°C (408 K) to 179°C (452 K) at a rate of l.l°C/min. under an autoclave pressure of 5.78atm, and the rise time taken is 40min. 

Because the actual pressure profile in the resin is as yet unknown, it is assumed that the void experiences a resin pressure of 0.1 atm during Stages 1 and 2, which then increases to 5.78 atm during stages 3-5. The resin never actually experiences the total autoclave pressure, so 5.78 atm represents an upper bound. 

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