Hygrothermal Ageing Influence on BVI-Damaged Carbon/Epoxy Coupons under Compression Load
Maria Pia Falaschetti1, Matteo Scafé2, Nicola Zavatta1
1Department of Industrial Engineering DIN, University of Bologna, Via Fontanelle 40, 47121 Forlì, Italy.
Polymers
|July 2, 2021
Summary
This study investigated how water absorption affects composite materials after impact. Hygrothermal aging significantly reduced compressive strength, more so than barely visible impact damage location.
Area of Science:
- Materials Science
- Aerospace Engineering
- Mechanical Engineering
Background:
- Composite materials are widely used in aerospace, facing challenges like barely visible impact damage (BVID) and humidity uptake.
- BVID is a common, hard-to-detect damage that, with aging, can lead to critical structural failures.
- Understanding environmental degradation is crucial for composite structure longevity and safety.
Purpose of the Study:
- To evaluate the effect of water absorption on the compressive residual strength of impacted composite specimens.
- To compare the influence of impact location (Near-Edge vs. Central) on aged composite behavior.
- To determine the relative impact of hygrothermal aging versus BVID on composite mechanical properties.
Main Methods:
- Composite specimens were impacted using a modified Charpy pendulum at Near-Edge and Central locations.
- Accelerated hygrothermal aging was performed by immersing specimens in water at 70 °C.
- Compressive residual strength was tested using the Combined Loading Compression (CLC) method, supplemented by Dynamic Mechanical Analysis (DMA).
Main Results:
- Hygrothermal aging demonstrably influenced the compressive residual strength of the composite specimens.
- The location of the barely visible impact damage (Near-Edge vs. Central) showed no clear, significant difference in aged specimens.
- Aged specimens exhibited a notable reduction in compressive strength, indicating significant material degradation.
Conclusions:
- Hygrothermal aging has a substantial impact on the compressive strength of composites.
- The effect of hygrothermal aging on compressive strength appears more pronounced than the influence of barely visible impact damage location.
- Further research is needed to fully understand the long-term effects of environmental factors on composite structures.
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