Journal Article

Damage Propagation and Residual Strength of Simple Block-Loaded CFRP Plates with Circular Holes under Tension–Tension Fatigue Conditions

Heinzlmeier, Lukas, Schagerl, Martin, Sieberer, Stefan, Wolfsgruber, Thomas, Kralovec, Christoph

2023

Overview

Holes and their effects on the fatigue behavior and damage propagation of thin-walled structural components remain objects of research. In this paper, the previously untreated effect of round holes in thin plain-woven carbon fiber-reinforced plastic plates subjected to simple block loading is examined, and the implication on both damage propagation and residual tensile strength is investigated. Using three-dimensional digital image correlation, the damage propagation in the performed experimental tests is acquired, and the damage size is quantified. The evaluations reveal a relationship between the damage propagation and applied load level, for which an empirical model has been previously established by the authors. As the number of cycles increases, a saturation behavior is found. Once the increased load is imposed on the plate, damage propagation resumes, leading to further damage propagation that can be described with the same empirical model as the initial damage propagation, including renewed saturation behavior. The subsequent experimental tests to determine the residual tensile strength reveal a positive effect of the existing damage size, as the ultimate load significantly exceeds the ultimate load of the non-damaged plate.

• Publisher: MDPI AG
• Subject: Block loading / Carbon fiber reinforced plastics / Carbon fibers / Composite materials / Critical path / Damage / Digital imaging / Discount coupons / Fatigue / Fatigue failure / Fatigue testing machines / Image acquisition / Laminates / Materials / Materials research / Mechanical properties / Plastic plates / Production processes / Propagation / Reinforced plastics / Residual strength / Strength of materials / Stress concentration / Tensile strength / Ultimate loads