T-W. Chou and R kaniva Table I Preforming techniques for a plate element Loading condition Bi-axial In- Transverse Weaving Angle-interlock Multi-axial weave · Tube rapier Lappet weaving Screw shafi Split-reeds Guide block 3D orthogonal Braiding Multi-step 3D solid braid Knitting Multi-axial warp knit Stitchin Cloth lamination for both bi-axial and in-plane shear loading are available for transverse loading Some of the multi-axial weaving techniques can be found only in patents and further development seems to be needed for practical use. Because of the general applicability of braided preforms to the loading conditions the basic concept of multi-step braiding is introduced below It has been found that the individual control of the rows and columns of yarn carriers on a Cartesian braiding bed allows for the fabrication of advanced 'multi- stepbraids; the micro-structural possibilities of three-dimensional braids are thus greatly extended. It also has been concluded that the traditional four-step and two- step braidings are special cases of multi-step braiding. The process of braiding Is termed multi-step because any number of steps may be specified in a given machine cycle. As an example, consider the machine cycle depicted in Fig. 2.The cycle consists of eight steps with one unit displacement for each. Figure 3 depicts the front view of 2-step and 4-step braided preforms. The majority of fibers in the 2-step preforms are aligned in the axial direction while the 4-step preform contains off-axis fibers, although fibers can be inserted in the axial and transverse directions. The process simulation of multi-step braiding allows for the identification of individual yarn paths, number and location of yarn groups, and braid geometry