Effect of stepwise gradient on dynamic failure of composite sandwich beams with metal foam core subject to low-velocity impact

• Published in: International journal of solids and structures Vol. 228; p. 111125
• Main Authors: Zhang, Wei, Qin, Qinghua, Li, Kaikai, Li, Jianfeng, Wang, Qiang
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.10.2021; Elsevier BV
• Subjects: Beams (structural); Carbon fiber-reinforced composite; Clamping; Composite beams; Density; Dynamic failure; Failure modes; Impact resistance; Indentation; Low-velocity impact; Metal foam; Metal foams; Sandwich beam; Sandwich structures; Stepwise gradient; Sandwich beam; Dynamic failure; Low-velocity impact; Stepwise gradient; Metal foam; Carbon fiber-reinforced composite
• ISSN: 0020-7683; 1879-2146
• DOI: 10.1016/j.ijsolstr.2021.111125

Dynamic failure behaviors of fully clamped and simply supported composite sandwich beams with stepwise gradient foam cores subject to low-velocity impact have been investigated experimentally. The sandwich beams with uniform foam core, positive-gradient foam core and negative-gradient foam core are designed and manufactured. The experimental results show that the mass distributions of cores have significant effect on the failure modes. The low-density foam layer at the impact end would lead to local failure mode of indentation or face fracture, while the high-density foam layer at the impact end would bring about global failure mode of combined core shear and debonding. The simply supported graded sandwich beam exhibits softening post-failure behavior, while the fully clamped graded sandwich beam displays hardening post-failure behavior. The initial strengths of fully clamped and simply supported sandwich beams with negative-gradient foam core are the highest, while the subsequent strength of the fully clamped sandwich beams with positive-gradient foam core is the highest. Among all gradient distributions of foam cores, the impact resistance of the fully clamped composite sandwich beams with negative-gradient foam cores design is the highest.