Composite materials are widely used in the construction of means of transport, including aircraft and helicopters. By appropriately selecting components and combining them in appropriate proportions and in a specific way, it is possible to profile the composite material to an element that carries specific loads, while reducing the mass that is so important in aircraft structures. In addition, the dynamic development of composites, which has been taking place in recent years, brings increasingly new solutions in the field of production, diagnostics, repair technology, protection against external conditions, protection against the impact of chemical factors, maintenance, etc. The growing trust in composites is expressed by the growing ratio of the amount of composite materials to the total amount of materials used in aircraft structures. However, similar to other layered composites, sandwich composites are also very sensitive to impact loads, even with very low energy values. Various measures are taken to reduce this defect, e.g. by using protective layers. The authors of the article, aiming at reducing the impact load effect on layered structures, propose replacing the classic sandwich composite with a multi-core sandwich composite, hence the main objective of the research was to investigate and describe the effect of low-energy impact loads on a multi-layer sandwich composite with cores in the form of polyvinyl chloride foam and additional reinforcement inside the core. The manufactured multi-core samples were subjected to a static tensile test, impact tests and puncture resistance tests. As a result of the tests, it was found that composites with a core of higher density exhibit higher impact strength values both under both surface and edge loading. It can also be seen that permanent post-impact deformations are greater in the case of composites with a core of higher density foam. The composite with a core of lower density exhibits higher tensile strength. Additionally, it was noted that the use of two cores with internal reinforcement in the form of a laminate made of glass fabric results in significantly better protection of the opposite cover and an increase in the impact strength of the sandwich composite. Keywords: composite, sandwich, core, impact strength, stress.