Nowadays, polymer based sandwich panels are widely used in industry because of their excellent physical properties compared to metalic alloys, such as lightness, high strength to weight ratio, and so on. Different mechanisms of damage occur during mechanical loading of the composites. Accumulated defects eventually lead to the composite failure. Matrix cracking, fiber breakage, and delamination are some of the damage mechanisms caused by these types of structures. It is necessary to identify the contribution of each mechanism to the ultimate failure of the composites. Non-destructive monitoring of this type of structures and prediction of damage with simulation by finite element method is very important. In this paper, damage mechanisms under low impact impact for sandwich panel made of glass / polyester shell and polyurethane foam core was investigated. In the present study, the shell and core of the sandwich panel was made manually and the sandwich sample was affected by the impact of 20 Joule, and during the test, acoustic data was stored by the installed sensor and was analyzed. Also, the impact process modeled using Abaqus FE software with explicit dynamic solver and damage mechanisms investigated applying cohesive bonding between layers and the proposed finite element model. The results obtained from the empirical test and simulation were discussed and there is a good agreement observed between them.