Mechanical evaluation of different repair concepts in thermoplastic and thermoset materials

Abstract

The repair process of thermoplastic and thermoset polymeric matrix composite materials is being increasingly demanded in the aeronautic industry for the need to know, in relation to the performed approximation, the recovery of residual strenght. To ensure the security and the viability of the repair processes, as well as its durability throughout its life cycle, it is necessary to perform the validation of the mechanical properties of structural elements after the repair process to eliminate defects and damages. The aim of this work is to validate, after aging, different damaged composite repaired coupons that have undergone different repair processes. The analyzed repair concepts are named as “Prepreg”, “Dry” and “Hybrid” for the thermoset material, and “Reconsolidation” and “Pre-consolidated patch” for different integration techniques of thermoplastic materials. Test coupons have reached H/W conditions according to applicable specifications. Additionally, different protections have been performed on the specimens to faithfully simulate ageing conditions. Furthermore, for each type of material and configuration, a reference test series meaning undamaged and unrepaired specimens has been tested to monitore in each case the level of recovered structural capacity. This activity is part of the CERES (Advanced Rear End Structural test program – low level tests) project, which is framed under Clean Sky 2 JU.