FRANCIS GONZALEZ - Academia.edu (original) (raw)
Uploads
Papers by FRANCIS GONZALEZ
Procceedings of the 24th ABCM International Congress of Mechanical Engineering, 2017
An experimental procedure was developed to characterize fatigue delamination growth in co-cured c... more An experimental procedure was developed to characterize fatigue delamination growth in co-cured composite joints. No-growth criterion was used to guarantee that crack growth does not reach an unsafe size during the lifetime of the component. The tests were performed for Modes I and II loading configurations, using the double cantilever beam (DCB) and the three-point bend end notched flexure (3-ENF) specimens respectively. The DCB tests were carried out following the ASTM D6115 procedure. There is no standard test procedure for conducting Mode II fatigue delamination tests. The ENF test was chosen based in previous works available in the literature and the ASTM D 7905. Information from previous quasi-static tests (using specimens with the same material batch and geometry) was used to define the load and displacement values for various G-levels, leading to a relationship between the maximum strain energy release rate (SERR-Gmax) and the number of cycles associated with the onset of delamination growth (G-N curve). Experimental results show that the co-cured joints exhibit an overall better fatigue performance in pure mode II loading. Additionally, SEM fractography studies were performed to both loading modes in order to analyze their morphology surfaces. The testing procedures used in this study, and the associated test results will be useful to develop robust criteria based on safe life design in composite aerostructures.
Procceedings of the 24th ABCM International Congress of Mechanical Engineering, 2017
An experimental procedure was developed to characterize fatigue delamination growth in co-cured c... more An experimental procedure was developed to characterize fatigue delamination growth in co-cured composite joints. No-growth criterion was used to guarantee that crack growth does not reach an unsafe size during the lifetime of the component. The tests were performed for Modes I and II loading configurations, using the double cantilever beam (DCB) and the three-point bend end notched flexure (3-ENF) specimens respectively. The DCB tests were carried out following the ASTM D6115 procedure. There is no standard test procedure for conducting Mode II fatigue delamination tests. The ENF test was chosen based in previous works available in the literature and the ASTM D 7905. Information from previous quasi-static tests (using specimens with the same material batch and geometry) was used to define the load and displacement values for various G-levels, leading to a relationship between the maximum strain energy release rate (SERR-Gmax) and the number of cycles associated with the onset of delamination growth (G-N curve). Experimental results show that the co-cured joints exhibit an overall better fatigue performance in pure mode II loading. Additionally, SEM fractography studies were performed to both loading modes in order to analyze their morphology surfaces. The testing procedures used in this study, and the associated test results will be useful to develop robust criteria based on safe life design in composite aerostructures.