Path-dependent bond-line evolution in equilibrated core honeycomb sandwich structures. (10th August 2020)

• Record Type: Journal Article
• Authors: Zebrine, Daniel; Anders, Mark; Centea, Timotei; Nutt, Steven
• Is Part Of: Advanced manufacturing. Volume 6:Number 3(2020)
• Page Start: 127
• Page End: 141
• Publication Date: 2020-08-10
• Subjects: Sandwich structures -- honeycomb core -- epoxy prepregs -- thermoset adhesives -- defect formation -- cure behaviors -- process monitoring -- autoclave processing; Composite materials -- Periodicals; Polymers -- Periodicals; 620.19205
• DOI: 10.1080/20550340.2020.1800194
• Languages: English
• ISSNs: 2055-0340

Abstract

Abstract: During co-cure of honeycomb core sandwich panels, composite facesheets are cured and concurrently bonded to the core, introducing complex interactions that can lead to unsatisfactory bond-line formation. In this work, an in situ co-cure fixture is employed to directly observe the adhesive during processing and identify defect formation mechanisms specific to the bond-line. Relating fillet quality to imposed core pressure reveals the non-linear effect of core pressure. High pressures suppressed voids; intermediate pressures resulted in void growth and entrapment within deformed fillets; and low pressures led to void rupture and small, irregular fillets. Experimental results aided in developing a model to predict void growth in the bond-line. The findings presented here provide insight into the physics controlling the adhesive bond-line evolution during co-cure, which can inform manufacturing decisions to produce higher-quality honeycomb core sandwich structures. Graphical Abstract: