The tolerance compensation on the winding pin - innovation in coreless fiber winding for high-precision fiber composite components
Abstract
Coreless filament winding enables the production of lightweight, high-performance fiber composite components, but suffers from limitations of existing anchor technologies. A new solution with tolerance compensation elements on the winding pin creates precise mounting surfaces and expands application possibilities for high-precision applications.
Advantages
- Geometrically high-precision fiber composite components
- Minimal use of materials
- Stress-free assembly of fiber composite components
Fields of application
Wherever complex and high-performance frame structures are required:
- Aerospace: ultra-lightweight frame and carrier systems such as antenna structures, satellite frames or aircraft parts
- Automotive: lightweight body and chassis components, battery housings or drive structures
- Mechanical and plant engineering, automation technology: components with minimal mass, lightweight components for highly dynamic movements, supporting structures for peripheral components (e.g. cable and hose guides) on moving assemblies
- Marine: lightweight and durable mast and rigging components as well as robust, corrosion-resistant elements for offshore applications
- Logistics: load carriers and modular, reusable transport structures for more efficient freight solutions
- Energy: support systems for photovoltaic systems or other energy structures
- Sports and leisure: lightweight and robust sports equipment such as bicycles, rackets, fishing rods, kayaks or drones
Background
Coreless filament winding (CFW) is an advanced manufacturing process for the production of lightweight, high-performance fiber composite components. By precisely aligning fiber bundles, this technology enables the design of tailor-made structures with high mechanical performance. Applications can be found in the aerospace, construction, automotive, and energy sectors, where the strength-to-weight ratio plays a crucial role. Unlike conventional processes, which require a mandrel, coreless fiber winding works without these cores. Instead, point-like anchors are used to place the fibers in a predetermined pattern. This method offers enormous freedom in the geometrical design, but is limited by the current state of anchor technology.
Problem
Existing anchor technologies face several challenges that limit the application possibilities and efficiency of coreless fiber winding. Classic anchors, such as hooks, nails or sleeves, not only limit the flexibility in the fiber arrangement, but also the alignment during subsequent assembly. Component positions cannot be tolerated using classic anchors, which is particularly difficult with highly rigid material systems. In the case of multiple screw connections, which connect the fiber composite components to other components by means of the anchors, the high geometric variation in coreless filament wound fiber composite components leads to misalignments. The geometric deviations, which usually occur in three dimensions, cannot be compensated for in a simple way, such as by using elongated holes in screw connections. This severely limits the use of such fiber composite components for high-precision applications.
Solution
By integrating tolerance compensation on the winding pin, a geometrically precisely defined mounting surface can be created, which allows a connection to another component to be made completely stress-free. The basis for this are cost-effective additional elements that are attached to the winding pin. These enable the production of precisely defined contact geometries by processing with commonly available processing machines (e.g. machining post-processing) without damaging the actual fiber structure. The precise geometry produced in this way enables the use of highly efficient coreless wound fiber composite components for a wide range of applications.
Figure 1: Section of a fiber structure (top) connected to a winding pin on a support structure. A white plastic disk is attached to the winding pin to compensate for tolerances. This has already been machined to the intended dimensions and mounted on an aluminum component (bottom of image). (Image University of Stuttgart, IFF, ITFT)
Literature and links
Pascal Mindermann und Götz T. Gresser. Adaptive winding pin and hooking capacity model for coreless filament winding. Journal of Reinforced Plastics & Composites, 2023, https://doi.org/10.1177/07316844221094777