Analysis of cyclic load die forming for woven jute fabric 3D reinforcement polymeric composites

摘要

2D fabrics are used widely and to good effect as a reinforcement for many planer composites and simple curved structures, i.e. a cylindrical arc. There are, however, manufacturing difficulties in the formation of composite structures which are curved across two axes, i.e. a bowl shape. This can be addressed by manufacturing 3D fabric preforms; however, this requires complex machinery and is slow and expensive. It is, therefore, desirable to form complex curved shapes from planer textile structures; this is either done by cutting a net shape from the textile and placing it on a mold or by using force to stretch the fabric to the mold. These methods, however, result in discontinuous reinforcement or poor distribution of phases, respectively. Wrinkling of the fabric during formation will increase the possibility of composite failure under loading because of the presence of rich fiber or resin areas. A new method was suggested to manufacture 3D shapes from 2D fabric through the application of cyclic loading on the 2D fabric under a continuous hot air till the final fabric prepreg bagging form is reached. The composite fabrication process was completed in two steps: imposing dynamic bagging of the chemically treated 2D Jute fabric with 16% sodium hydroxide in slack form to fit the die final shape prior to the infusing of the resin accompanied by pressing two halves of the mold. A proto-type setup was designed to study the two-step fabrication method for various shapes of 3D fabric reinforcement.