Filament-winding pattern

Table 5.13 Different filament winding patterns meet different performance requirements... 

Kandola, A., Processing software for easy filament winding pattern generation . Advanced Composites Bulletin, 2010, August, 6. 

Figure 7-90. Examples of different filament-winding patterns that can be used in designing to meet different performance requirements.

Halpin (1) and Tsai (2) have presented treatises that address the effects of fiber content, orientation and properties on the composite s mechanical performance. A numerically controlled filament winding machine is capable of placing fiber in precise, three dimensional, engineered patterns. Future research addressing the molecular role of the resin s infrastructure on mechanical performance, will couple filament wound composite... 

In filament winding the fiber is wound to form a desired pattern, usually but not necessarily hollow and cylindrical. The fiber is passed through the resin and then spun onto a mandrel. After the desired number of layers of fiber is added, it is cured. Prepregs can be filament wound. With the advent of new machinery, complex shapes and designs of the filament can be readily wound. 

The mechanical properties of the filament wound composite are a complex combination of (a) winding pattern and thickness and (b) resin and filament properties. The mechanical properties of the dome regions, in particular, require specialized treatment. The interested reader is referred to the text by Fubin for more information. 

Filament-Winding. This requires a mandrel to shape the desired finished product. Continuous filament or woven tape is fed through a liquid resin bath to impregnate it, and then wound onto the mandrel in a calculated pattern to optimize the final properties (Table 15.27). The assembly is oven-cured. A collapsible mandrel can then be removed from the plastic product or the mandrel can be left as a part of the finished product. These are the strongest plastic products ever made. Typical products are pipes, tanks, and pressure bottles. Other suggested products... 

The ATL and AFP processes are thus a cross between filament winding with its elaborate automated patterns of fibre laydown and unidirectional prepreg layup with its reliance on the autoclave. The use of automated robotic machinery for the layup gives increased layup speed (vital to economically manufacture these large items in feasible timescale), consistency and freedom from errors compared with manual techniques, as well as ensuring precision in the placement of the tows and tapes. 

Closure In filament winding, it is the complete coverage of a mandrel wdth fiber. When the last tape circuit that completes the mandrel coverage is laid down adjacent to the first without gaps or overlaps, the winding pattern is said to have closed. 

Fig. 2. Thermal expansion of filament-wound samples. The winding pattern is o-xxxx-o-xxxx (x = 45°).

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