Book excerpt: The rising demand to reduce fuel consumption and the continuous increase of materials and manufacturing costs has obliged aircraft manufacturers to boost the use of composite materials and to optimise the manufacturing methods. Foam core sandwich structures combine the advantages of high bending properties with low manufacturing costs when liquid composite processes are used. However, the use of foam core sandwich structures is not widespread in aircraft applications due to the better weight-specific performance of honeycomb cores and the susceptibility to impact loading. In this context, pin reinforcements are added to the foam core to improve its mechanical properties and its damage tolerance. This work contributes to the understanding of the mechanical behaviour of pin-reinforced foam core sandwich structures under static and impact loading. Ultrasonic scan and micro-computed tomography are used to identify the different damage modes. The effect of very low temperature on the damage behaviour under impact loading is investigated. An explicit simulation model to predict the impact response of pin-reinforced foam core sandwich structures is also proposed.