Compression and impact testing of two-layer composite pyramidal-core sandwich panels

• Published in: Composite structures Vol. 94; no. 2; pp. 793 - 801
• Main Authors: Xiong, Jian, Vaziri, Ashkan, Ma, Li, Papadopoulos, Jim, Wu, Linzhi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2012; Elsevier
• Subjects: Applied sciences; Carbon fiber; Carbon fibers; Composite; Composites; Compressing; Compression; Compression tests; Energy absorption; Exact sciences and technology; Forms of application and semi-finished materials; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Impact tests; Low velocity impact; Physics; Polymer industry, paints, wood; Pyramidal truss core; Sandwich construction; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Struts; Technology of polymers; Trusses; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Pyramidal truss core; Compression; Composite; Carbon fiber; Low velocity impact; Interfacial layer; Volume fraction; Low speed; Fiber reinforced material; Static load; Energy dissipation; Carbon fiber reinforced plastics; Buckling; Static test; Damaging; Textile fiber; Rupture; Sandwich structure; Quasi static theory; Compression test; Weight; Truss structure; Glass fiber; Energy absorption; Crush; Impact test; Mechanical shock
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2011.09.018

Quasi-static uniform compression tests and low-velocity concentrated impact tests were conducted to reveal the failure mechanisms and energy absorption capacity of two-layer carbon fiber composite sandwich panels with pyramidal truss cores. Three different volume-fraction cores (i.e., with different relative densities) were fabricated: 1.25%, 1.81%, and 2.27%. Two-layer sandwich panels with identical volume-fraction cores (either 1.25% or 2.27%), and also stepwise graded panels consisting of one light and one heavy core, were investigated under uniform quasi-static compression. Under quasi-static compression, load peaks were identified with complete failure of individual truss layers due to strut buckling or strut crushing, and specific energy absorption was estimated for different core configurations. In the impact test, the damage resulting from low-velocity concentrated impact was investigated. Our results show that compared with glass fiber woven textile truss cores, two-layer carbon fiber composite pyramidal truss cores have comparable specific energy absorptions, and thus could be used in the development of novel light-weight multifunctional structures.