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.

已经通过实验研究了具有阶梯式梯度泡沫芯的全夹紧和简支复合夹层梁在低速冲击下的动态破坏行为。设计制造了均匀泡沫芯、正梯度泡沫芯和负梯度泡沫芯的夹心梁。实验结果表明，岩心的质量分布对失效模式有显着影响。冲击端的低密度泡沫层会导致压痕或面断裂的局部破坏模式，而冲击端的高密度泡沫层会带来芯部剪切和脱粘组合的整体破坏模式。简支渐变夹层梁表现出软化后的失效行为，而完全夹紧的渐变夹层梁表现出硬化后的失效行为。负梯度泡沫芯全夹紧和简支夹芯梁的初始强度最高，而正梯度泡沫芯全夹紧夹芯梁的后续强度最高。在泡沫芯材的所有梯度分布中，负梯度泡沫芯材设计的全夹紧复合夹芯梁的抗冲击性最高。