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Thermomechanical modelling for the consolidation of hybrid bicomponent fiber preforms
This work shall obtain the needed material characteristics and develop a thermomechanical consolidation model for bicomponent fibers based on the similarities of the microscopic mechanisms to those occurring in sintering.
**Motivation**
Today, fiber-reinforced composites are broadly considered to be lightweight but labor intensive alternatives to conventional engineering materials and are thus seldom chosen for high volume production schemes. Let’s change that!
Composites with thermoplastic matrix systems offer alternative processing routes and provide a higher potential for recyclability than those containing conventional thermosets. However, the desired low cycle times are currently only achievable in stamp forming using comparatively expensive organosheets. Stamp forming of thermoplastic composites is still a promising method for high volume production and facilitates the transition of using composite materials in existing sheet press plants. The issue at hand lies not with the process, but with the intermediate material.
**Thermoplastic Sheath Bicomponent Fibers**
The concept of providing continuous reinforcement fibers which are individually coated with a thermoplastic polymer as feedstock for stamp forming fills that gap, because the composite has a complete wet-out to begin with and only needs to be consolidated.
The fabrication of such bicomponent fibers is not trivial. CMASLab investigates high-speed coating processes based on dilute polymer solutions as methods of manufacture.
**Motivation** Today, fiber-reinforced composites are broadly considered to be lightweight but labor intensive alternatives to conventional engineering materials and are thus seldom chosen for high volume production schemes. Let’s change that!
Composites with thermoplastic matrix systems offer alternative processing routes and provide a higher potential for recyclability than those containing conventional thermosets. However, the desired low cycle times are currently only achievable in stamp forming using comparatively expensive organosheets. Stamp forming of thermoplastic composites is still a promising method for high volume production and facilitates the transition of using composite materials in existing sheet press plants. The issue at hand lies not with the process, but with the intermediate material.
**Thermoplastic Sheath Bicomponent Fibers** The concept of providing continuous reinforcement fibers which are individually coated with a thermoplastic polymer as feedstock for stamp forming fills that gap, because the composite has a complete wet-out to begin with and only needs to be consolidated.
The fabrication of such bicomponent fibers is not trivial. CMASLab investigates high-speed coating processes based on dilute polymer solutions as methods of manufacture.
Thesis Objectives
The consolidation behavior of hybrid bicomponent fibers is expected to differ significantly from that of other hybrid preforms for thermoplastic composites, which is mainly governed by microscopic impregnation flows. The concept of bicomponent fibers circumvents any impregnation flows altogether. Here, consolidation is governed by the surface energies of the melted thermoplastic sheats, the mechanical compaction and nesting behavior of the core fibers and ultimately also by the enthalpies related to melting and solidification of the used polymer.
This work shall obtain the needed material characteristics and develop a thermomechanical consolidation model based on the similarities of the microscopic mechanisms to those occurring in sintering.
**Your Profile**
- Interested in modeling and empirical work
- Ideally experience with methods of finite differences or finite elements
Thesis Objectives The consolidation behavior of hybrid bicomponent fibers is expected to differ significantly from that of other hybrid preforms for thermoplastic composites, which is mainly governed by microscopic impregnation flows. The concept of bicomponent fibers circumvents any impregnation flows altogether. Here, consolidation is governed by the surface energies of the melted thermoplastic sheats, the mechanical compaction and nesting behavior of the core fibers and ultimately also by the enthalpies related to melting and solidification of the used polymer.
This work shall obtain the needed material characteristics and develop a thermomechanical consolidation model based on the similarities of the microscopic mechanisms to those occurring in sintering.
**Your Profile** - Interested in modeling and empirical work - Ideally experience with methods of finite differences or finite elements
ETH Zurich
Christoph Schneeberger
CLA E 32.2
Tannenstrasse 3
8092 Zurich
Phone: +41 44 633 63 08
cschneeb@ethz.ch
www.structures.ethz.ch
ETH Zurich Christoph Schneeberger CLA E 32.2 Tannenstrasse 3 8092 Zurich