Kandreegula, S., Mukherjee, S., Jain, R., Prasad, S. et al., "FEM based Approach for Design and Development of Exhaust System Flex Connector and Experimentally Validated," SAE Technical Paper 2017-01-1079, 2017, doi:10.4271/2017-01-1079.
Flex Connectors are intended for mitigating the relative movement of exhaust system components along the axis of the system arising from the thermal expansion due to intermittent engine operation. Flex connectors must not be installed in locations, where they will be subjected to destructive vibration. Hence, the stiffness of the flex connector plays an important role, while designing or selecting the right design.It consists of a multi-ply bellows combined with an inside and an outside steel braid. The liner is included to reduce the temperature of the bellows and improve flow conditions. The braid is included for mechanical protection and to limit the possible extension of the joint. It has only axial translational motion.Instead of conventional approach, Finite Element Method has been adopted to align the project time plan (design and development time), to predict the static and dynamic stress levels along with the vertical, lateral and torsional frequencies for defining the design parameters (stiffness) of the flex connector suitable for the operating environment. Then, this flex connector has been tested under VECV standard durability cycles - to measure strain values and frequencies at defined locations and validated with the CAE results.The FE simulation have helped us in selecting the right parameters for the design and ensure First Time Right at the development phase. It implies reduction in number of physical trails and thereby achieving considerable time and cost saving for design and development phase.