Influence of winding speed and winding trajectory on tension in robotized filament winding of full section parts W. Polini, L. Sorrentino * Dipartimento di Ingegneria Industriale, Universita ` degli Studi di Cassino, via G. di Biasio, 43, 03043 Cassino, Italy Received 3 November 2004; received in revised form 24 January 2005; accepted 27 January 2005 Available online 23 February 2005 Abstract When composite parts are manufactured by robotized filament winding technology, winding tension is a very important param- eter to be controlled since it influences directly the defects and the mechanical property of these parts. The present work aims to study the influence of the main winding parameters on tension during the manufacturing of full section composite parts. In partic- ular, the focus of this work is to determine both the geometric parameters characterizing the winding trajectory and the winding speed that allows to keep the winding tension near to the nominal value that has been planned to have good composite parts. The geometric parameters of the winding trajectory are the number of points used to approximate the winding trajectory, the tra- jectory angle and the distance of the deposition system from the winding die in order to avoid collisions (called safety distance). The conclusions developed in this work may be used to understand the change in tension average value of winding typology. Ó 2005 Elsevier Ltd. All rights reserved. Keyword: Filament winding 1. Introduction Robotized filament winding technology manufactures a composite part by an industrial robot, opportunely equipped with a feed and deposition system, and a wind- ing die: coordinating the relative motions of these two parts it is possible to describe a 3D deposition trajectory of the roving on the winding die [1]. The process in- volves the pre-impregnated roving deposition, according to the planned robot trajectory, and its polymerization with the composite part closed between a winding die and a die, that may be accomplished in a furnace for thermoset resin matrix. Robotized filament winding is able to manufacture complex composite parts character- ized by high performances (i.e., the ratio between vol- ume of fibres and volume of part is higher than 50–60%). Winding tension is a parameter to be controlled for robotized filament winding technology, since it influ- ences directly the compaction and the alignment of the fibres. Composite resistance against loads applied along roving deposition direction of the resulting part is due to both the presence of defects in the work-piece and to its fibre percentage [2,3]; the higher the fibre percentage is in a unitary volume, the greater the work-piece mechan- ical resistance. It is possible to adjust the amount of fi- bres for a unitary volume by means of winding tension that influences the fibre compactness. The choice of the winding tension value and the need to keep it constantly to the chosen value are two aspects strongly connected to the geometry of the part to be wound. The present work focuses on parts with a full section parts. It is impossible to manufacture this kind of parts by traditional technology, while it is possible, 0266-3538/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.compscitech.2005.01.007 * Corresponding author. Tel.: +39 776 2994012; fax: +39 776 2993886. E-mail address: sorrenti@unicas.it (L. Sorrentino). URL: www.unicas.it (L. Sorrentino). Composites Science and Technology 65 (2005) 1574–1581 www.elsevier.com/locate/compscitech COMPOSITES SCIENCE AND TECHNOLOGY