Fastening solutions on composite structures: Progressive damage analysis of a unique bolted joint design for single-lap CFRP laminate

This study tested a unique assembly method using single and multi-body sleeves with carbon fiber-reinforced plastic (CFRP) to improve load-carrying capacity in single-lap joints. Advanced techniques were implemented into FE code to simulate progressive material degradation behavior. Ti6-4 bolt, insert, and washers with AISI 304L sleeve joint were conceptually designed to keep bolt and nut together with less relative motion. Failure indices were reduced by 16–54%, damage initiation force was improved by 8–40%, and inter-plate clamp loss was reduced by 18% compared to the sleeveless design. Lateral load-carrying capability of joint and inter-plate clamp load significantly improved.