INVESTIGATION OF INFLUENCE OF DIFFERENT PIERCING METHODS OF ABRASIVE WATERJET ON DELAMINATION OF FIBER REINFORCED COMPOSITE LAMINATE

摘要

Due to the highly abrasive nature of composite materials, cutting composites with traditional rotary cutting tools such as a band saw or Dremel? tool is a challenge. Cutting composite materials often results in tool wear, high heat, and dust generated during the cutting process. Thermoplastic reinforced composites can be especially challenging to machine because of their tendency to melt due to the high heat generated during cutting. If the melted material gums up the cutting blade, the cutting equipment is no longer able to cut the material effectively. Abrasive waterjet cutting (AWJ) does not have direct contact between the machine and material, so many of the machining challenges are avoided. However, the impact of a waterjet stream may cause delamination of composite laminates. This research addresses the influence of different piercing methods of the waterjet cutting process on delamination of the composite laminate. The investigated geometry is a 25.4 mm x 101.6 mm carbon fiber laminate which is manufactured using 3 plies, 6 plies, and 30 plies of plain weave carbon fiber prepreg. The axial centerline of the sample will be pierced and cut using four different kinds of piercing methods; stationary piercing, dynamic piercing, low-pressure piercing, and very brittle material piercing. After cutting the sample with water jet, the delamination zone of the composite laminate will be observed using a Computed tomography (CT) scanning technology. The analysis shows that the distribution of delamination and the size of delamination depends on the different piercing methods.