OVERVIEW OF TEXTILES
Fig. 2-22. Waviness induced in warp weavers in a 3D interlock weave by
compression during processing.
Measuring geometrical irregularity in textile composites is very difficult; predicting
it from process models probably impossible. Therefore, detailed knowledge of types and
degrees of irregularity are not likely to become part of any practicable scheme for predicting
strength and life. More reasonably, the degree of regularity should be correlated
experimentally with process parameters, so that a maximum degree of irregularity can be
guaranteed given sufficient quality control in composite fabrication. While irregularity is
difficult to quantify, it dominates strength and fatigue life and therefore must be able to be
bounded for textile composites to be regarded as reliable. Neither should any model of a
textile be accepted as giving accurate predictions without an assessment of how irregularity
would affect the outcome.
Fig. 2-23. Tracings of yarn cross-sections in a 3D braided composite (from [2.29]).
2.4 Integral Structures made by Textile Processes
The performance and manufacturing advantages of eliminating joints make integral
structures a particularly exciting prospect in textile composite technology. Unfortunately,
models for integral structures are not yet developed and they therefore receive little attention
in the remainder of this handbook. A few examples are offered here in anticipation of future
developments.
