Strength enhancement of notched composite pultruded shafts by repairing with woven and knitting fabrics

Composite shafts can be damaged because of unsuitable production, mistaken assemblage, and excessive strain. Repairing of damaged composite shafts with patch or an alternative approach is an economical solution. This study aims to enhance the tensile, compressive, and four-point bending loads of notched E-glass/vinylester composite pultruded shafts by repairing with different patch materials. For this purpose, the notched composite shafts having 1mm, 1.5mm, and 2mm notch depths were repaired with E-glass woven fabric, rib knitting fabric, and milano knitting fabric with 30mm, 50mm, and 70mm widths by winding method. The results of the repaired composite shafts were compared with unrepaired composite shaft to better understand the influence of type and width of patch and notch depth on the critical damage load. The results showed that the repairing with E-glass woven and knitting patches increased the critical damage load of notched composite shafts by about 67%.