Improved molding technology for running feet blades

Abstract

Large composite structures are often difficult to design and produce due to the need for large and expensive molds. For the best accuracy, most of these molds are CNC cut out of large blocks of expensive and often heavy materials like invar, steel, and aluminum. Other methods such as carbon composite molds are also standard in the production of composites as they are light and match the thermal expansion of the parts being made but are again expensive and require even more steps to manufacture. Other methods like bending a flat panel into the shape result in not very accurate tools and are often made of thin metal that is prone to warping during curing.In this thesis, a design case is made for a modular mold that fits in the current production that would allow for the lay-up of a single foot and upwards. This would reduce material cost by utilizing thinner rolls of unidirectional fibers than usual. The mold costs would also be decreased as the need for a continuous mold surface is not necessary. Analyzing the current and potential problems that can occur during the manufacturing process is important for understanding and designing a solution that solves this. Utilizing axiomatic design principles to decide on design parameters for an initial concept for tool meeting these parameters. From this concept, a prototype ready for production and testing is designed in CAD. This prototype is analyzed with FEM simulation to inspect the possible deformation and stress in the design.