One of the major concerns in design of structural adhesive bonding for aircraft and spacecraft is the toughness and reliability.However,as the bonded joints are toughened,there comes the need for other important functionalities.These include typically the electrical conductivity,thermal conductivity,damping property and fire retardation property,etc.In an analogue to the requirementsand technological challenging similar demands exist inthe structural composites.For the composites,the interleaf-toughening concept has been successfully demonstrated to increase the impact damage resistance.