| Abstrakt: |
Compression, and relaxation of a reinforcement fabric during composite manufacturing dictates mold design, resin flow, and fiber volume fraction of resultant composite; and single layer fabric architecture, and numbers of layers in a fabric stack change the compressibility character of overall reinforcement material. This study dealt with the effect of knit architecture and number of layers on dry compression and relaxation responses of weft knitted fabrics from glass yarn. Fabric architectures of 1x1, 2x2, English, and Fisherman ribs were selected. The thicknesses of single-, double-, and triple-fabric layers from same knit architectures were measured under compression and recovery pressures ranging from 2 to 200 kPa. Areal densities of single layer fabrics were measured. 2x2 and fisherman rib fabric architectures exhibited higher thickness, areal density and fiber volume fraction than 1x1 and English rib fabric architectures due to their nested and compact structures. Due to nesting between adjacent layers; multi-layer fabrics demonstrated higher fiber content than single layer fabrics. The difference between the compression and recovery thicknesses proved the existence of dissipated energy. Compression curves - the relationship between fiber volume fraction and compression pressure - classified by number of layers were fitted by square equation with fairly high determination of coefficients (R2). |
