Compaction of textile reinforcements for composites manufacturing. I: Review of experimental results

Abstract

As new developments are brought to the group of manufacturing processes for composite parts known as liquid composites molding (LCM), the compaction behavior of the textile reinforcements is increasingly seen as an important parameter of the definition of these processes. The evolution of the permeability tensor of the reinforcements with time, the general kinetics of the manufacturing operations, and the modelization of these processes depend on a large extent on the compaction behavior of the reinforcements used, especially in flexible‐wall RTM and autoclave molding. Also, more research efforts are devoted toward the development of a complete analytical model of the properties of heterogeneous textile reinforcements. In this paper the published experimental data related to the compaction and relaxation of random mats and woven reinforcements are gathered. Observed parameters are defined, which allow numerical comparisons of the experimental curves to be made, as well as the identification of general trends seen with most tested reinforcements. The effects of various processing parameters are identified, and relations to published analytical models of the mechanical properties of fibrous assemblies are discussed.

Digital element simulation of aligned tows during compaction validated by computed tomography (CT)

“…These manufacturing processes involve compaction of the dry preform to a certain level of pressure which changes the tow geometry of the preform affecting the fibre volume fraction and the resin permeability. Based upon these facts, the compaction process is taken as an important parameter of the manufacturing process (Robitaille and Gauvin, 1998). Extensive research has been done on the compaction behaviour of textiles (Chen and Chou, 1999;Chen et al, 2001;Chen et al, 2006;De Jong et al, 1986;Gutowski and Dillon, 1992;Latil et al, 2011;Nguyen et al, 2013;Pearce and Summerscales, 1995).…”

Influence of Tow Architecture on Compaction and Nesting in Textile Preforms

“…During autoclave curing, significantly higher pressures (around 7 bar) are applied resulting in a reduction in thickness and a corresponding increase in fibre volume fraction. As a result it is important to characterise the compaction behaviour during the composite manufacturing process [3].…”

Analysis of void formation in thermoplastic composites during resistance welding

“…[34][35][36] If the consolidated laminates are reheated, the residual compression stress previously stored in the fabric might be released due to the reduction of matrix stiffness at elevated temperatures. Such process is usually referred to as fibre de-compaction.…”