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Study of Allowable Interlaminar Normal Stress Based on the Time-Temperature Equivalence Principle in Automated Fiber
Rui Xiao1, Jiaqi Shi1, Jun Xiao1
1College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Polymers
|December 10, 2021
Summary
This study introduces allowable interlaminar normal stress to predict concave surface delamination in automatic fiber placement (AFP). Experimental data guide AFP parameter selection, improving composite material manufacturing.
Area of Science:
- Materials Science
- Manufacturing Engineering
- Composite Materials
Background:
- Automatic fiber placement (AFP) is crucial for composite material manufacturing in aviation.
- Concave surface delamination is a common AFP defect with insufficient research on its occurrence conditions.
Purpose of the Study:
- To propose and define allowable interlaminar normal stress for predicting concave surface delamination in AFP.
- To experimentally investigate the relationship between laying speed and allowable normal stress.
Main Methods:
- Probe tests utilizing the time-temperature equivalence principle were conducted.
- Analysis combined viscoelastic theory and the molecular diffusion reptation model.
- Experimental data were used to guide AFP engineering parameter selection.
Main Results:
- A laying speed/allowable normal stress curve was generated and analyzed.
- The physical meaning of allowable normal stress was discussed.
- Dominating effects in metal/prepreg and prepreg/prepreg layer formation were identified.
Conclusions:
- The proposed allowable interlaminar normal stress effectively predicts delamination in AFP.
- Experimental data and theoretical models provide insights into defect formation mechanisms.
- The findings are applicable to optimizing AFP process parameters in engineering applications.
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