Experimental Study on Rapid Repair of Foam Sandwich Composites for Radome with Low-velocity Impact Damage

Abstract

Sandwich structure composites are commonly used in Radar radomes, the core materials mainly include honeycomb material and foam material. Impact damage is the greatest threat to this kind of structure. In this paper, low-velocity impact damage was simulated by drop hammer test, while ultrasonic phased array technique was used as NDT(Non-Destructive Testing Technology), and restored by scarf repair technique. The mechanical properties and the electromagnetic wave performance of the foam sandwich panel before and after repair were carried out comparatively. The results show that, the flexural strength can restore 112.7% of the undamaged plate, and the lateral compressive strength can restore 85.1%. The repair efficiency calculated from tests was observed to be 135% and 50.7% respectively. Besides, electro-magnetic wave permeability was improved apparently. The method for repairing the low-velocity impact damage of the foam sandwich structure can meet the requirements of the rapid repair for practical radome structure.