Grant: Alliance Grants

The automotive sector is under pressure to reduce vehicle weight to reduce fuel consumption and green house gas emissions, while improving vehicle safety. To achieve this goal, steel manufactures have designed new high strength/high ductility steels to lighter vehicle structures. These steels have led to new vehicle structure design possibilities. To maximize options for design optimization, virtual design techniques have been developed to virtually optimize vehicle part strength and stiffness according to predetermined factors. Material data is needed to implement virtual design methodologies. This is easily obtained for sheet materials, which is very consistent. However, static and cyclic (fatigue) weld strength is highly dependent on joint geometry, welding process parameters and weld geometry. Although weld strength may be determined experimentally, testing all possible configurations is onerous. In the past, full structures were build and tested to confirm designed strength. However, full-scale testing is cost prohibitive. The proposed project will for the first time understand how welding and manufacturing variability systemically affects static and cyclic joint strength. This understanding will be used to build an finite element model to predict joint strength and build a large data database to develop a novel machine learning (ML) predictive algorithm that can be widely applied in industry to implement the findings of this research. This project will i) characterize how welding process and weld geometry affect fatigue strength of automotive joints, ii) develop a novel ML model to predict post-weld geometry from weld process data, iii) develop ML models to predict weld fatigue life of a weld particular weld geometry, iv) develop a methodology use the ML models to create data suitable for automotive design optimization. The know-how developed from this project will contribute to the competitiveness of Canada's automotive industry, allowing Canadian vehicle designers to easily design new light and safe automobiles made from the newest steels, reducing green house gas emissions of gas-power vehicles and enabling the production of new electric vehicles.