The InHeatPro is a TSB funded three year project, which targets on delevoping a ‘smart-patch’ system with a reliable, low cost, integrated sensor network that will act as part of a feedback control system for active cure control to optimise both adhesive mechanical properties and minimise residual stress. The sensors will also be used as active transducer elements to enable non-destructive inspection of the patch to with a high probability of detection for voids and disbonds that are equal to or larger than the critical size. Bonded composite patches are used to repair corrosion, fatigue and impact damage to airframes due to their superior mechanical integrity characteristics compared with mechanically fastened repairs. Such repairs also reduce aircraft down-time, maintenance labour costs and enable useful life extension. Success of a bonded repair is critically dependent on achieving suitable surface preparation and cure under difficult field conditions. Expanding the scope of patch repairs to primary load bearing structures, requires an added level of assurance that voids/disbonds are below a critical size threshold and that cure conditions result in adequate adhesive shear modulus without high residual stress.
