Kordsa (Istanbul, Turkey) is a global supplier of tire and building reinforcement and composite materials technologies. It recently expanded its aerospace capabilities through the acquisition of multiple US companies. The company is also constantly expanding its business in the automotive and heavy truck sectors. At the Turk Kompozit Composite Materials Summit held in Istanbul, Turkey in October 2019, the company discussed the weight reduction technology of the heavy truck chassis system jointly developed by Kordsa and Ford Otosan under the title "Development of Kordsa Heavy-Duty Composite Leaf Spring Materials" , And a monitoring system for process optimization, parts inspection and online health diagnosis.
Chassis components are an excellent opportunity for composite applications, because they account for the largest percentage of the car body weight and are structural components that are subject to dynamic loads.
Kordsa and Ford Otosan's goal is to reduce weight by producing composite leaf springs (75% weight reduction compared to steel), reduce CO2 emissions and improve fuel efficiency and payload. This will also reduce the unsprung weight of the vehicle to reduce subsequent weight in other systems, and improve comfort by reducing noise, vibration and roughness (NVH).
Achieving performance goals for heavy truck leaf springs is extremely challenging. It must bear an axle load of 13.4 tons, and withstand harsh service environments, and have a long-term fatigue life of at least 1 million kilometers. Therefore, this thick composite part (maximum 110 mm) must have a sufficiently high fiber volume and low porosity, as well as a glass transition temperature (Tg) between 120-150 ° C. The productivity must match the productivity of the heavy truck (up to 10,000 parts per year) so that the curing cycle is less than 1 hour and the cost must be competitive.
Kordsa and Ford Otosan chose prepreg compression molding because it can obtain a uniform resin distribution and optimized stiffness by improving fiber arrangement, reducing deformation and thickness changes, and the process has high reliability and Repeatability. Kordsa produced a variety of unidirectional carbon fiber and glass fiber / epoxy prepregs, and performed a complete material characterization of each material, and developed the material data required by Ford Otsan for input into computer-aided engineering (CAE) tools in. Then, it tried to fully refine the load of the prototype heavy-duty card composite leaf spring, and used fiber Bragg grating (FBG) sensors to verify the load and explore process parameters and fatigue characteristics.
The final prototype product is 75% lighter than steel, while improving tensile strength, compressive strength and fatigue resistance. Kordsa will continue to work with Ford Otosan and other transportation manufacturers to reduce the weight of cars, trucks, airplanes and ships through lighter composite structures, thereby reducing CO2 emissions globally.