En teoretisk modell för 3D-printing av fälg i kolfiber

Sammanfattning: The automotive industry faces the challenge to manufacture vehicles with reduced material usage and climate impact. To achieve this the industry has begun using other materials such as carbon fibre composite than materials such as steel and aluminium which are normally used for the manufacturing of automobile parts. Because its anisotropic structure gives the manufacturer increased opportunity to selectively use the material for the part’s stability and ability to withstand loads However Carbon fiber has drawbacks, the material is time-consuming to work with and expensive, because such automobile parts are either made by hand or with precisio nmolding equipment that requires experienced and educated personnel to produce parts with satisfactory quality. A car component whose weight reduction is crucial is the car rim. The car rims and tire’s weight determines the wheel shaft’s torque needed for steering which makes it an important component of the car. This work examines a manufacturing technology with the potential to reduce material use and the climate impact of car rims manufacturing. The manufacturing technology involves a robotic system that weaves carbon fiber threads on a winding frame that sits on a rotary table. The work’s purpose is to derive a theoretical model which describes the following characteristics: Production time, material usage, how the carrim and winding frame are to be adapted to one another to ensure the car rim can withstand loads to which it can be expected to be subjected.The objective is to generate data which describes these characteristics. To derive a theoretical model and generate data which describes the manufacturingstechnology’s characteristics, the work was split into two parts; In the first part, a theoretical formula was derived to relate material usage with the used length of a carbon fibre thread. Simulations are made to relate material usage and production time with theory for a PID-regulator.In determining the weaving pattern, material technology’s theory for anisotropy is used. The second part involves using theory from solid mechanics to derive theoretical equations which describes how the winding frame and car rim’s dimensioning are to be adapted to one another, with regards to the car rim’s critical parameters. Which in this work is the car rim’s stiffness and carbon fibre’s yield strength. To test the mechanical performance of the car rim, Finite-element-method(FEM) simulations are made and the validation of the simulation is done with the derived theoretical equations. In simplifying the work, winding frame, weaving pattern, and car rim are visualized using Computer-aided-design(CAD) tools. The conclusion from the results is that while the theoretical model showcases the manufacturing technology’s potential but further work is needed to improve it and adapt it to car rim’s industrial standards.