Holistic and Consistent Design Process for Hollow Structures Based on Braided Textiles and RTM

Abstract

The present paper elaborates a holistic and consistent design process for 2D braided composites in conjunction with Resin Transfer Moulding (RTM). These technologies allow a cost-effective production of composites due to their high degree of automation. Literature can be found that deals with specific tasks of the respective technologies but there is no work available that embraces the complete process chain. Therefore, an overall design process is developed within the present paper. It is based on a correlated conduction of sub-design processes for the braided preform, RTM-injection, mandrel plus mould and manufacturing. For each sub-process both, individual tasks and reasonable methods to accomplish them are presented. The information flow within the design process is specified and interdependences are illustrated. Composite designers will be equipped with an efficient set of tools because the respective methods regard the complexity of the part. The design process is applied for a demonstrator in a case study. The individual sub-design processes are accomplished exemplarily to judge about the feasibility of the presented work. For validation reasons, predicted braiding angles and fibre volume fractions are compared with measured ones and a filling and curing simulation based on PAM-RTM is checked against mould filling studies. Tool concepts for a RTM mould and mandrels that realise undercuts are tested. The individual process parameters for manufacturing are derived from previous design steps. Furthermore, the compatibility of the chosen fibre and matrix system is investigated based on pictures of a scanning electron microscope (SEM). The annual production volume of the demonstrator part is estimated based on these findings.

Manufacturing processes for braided composite materials

“…Potluri et al proposed a linear design strategy, where the modeling is done in roughly the same order as the physical production [7]. Gn€ adinger et al showed the mutual dependencies of the various design features while striving for virtual design process chain integration [78]. They also showed the lack of integration of braiding process modeling and downstream resin infusion process modeling.…”

Experimental and numerical studies on compaction of carbon fiber composite joint with variable cross‐section using thermal expansion process

“…It should be noticed that most studies focused on composite structure with constant or regular cross‐section profiles, whereas few studies were conducted on hollow composite structure with complex and variable cross‐section profile. With increasing requirements for structural efficiency in marine and aircraft applications, composite products with variable cross‐section are increasingly used , and thermal expansion process is a good choice for integral forming of such structure. For composite structure with constant cross‐section, the shape of core mold is regular and uniform thermal expansion of core mold is generally obtained at each region, resulting in uniform compaction pressure distribution on composite.…”