Optimization of Hydroformed Exhaust Gas Recirculation Tube under Vibrational Load by Finite Element Analysis

This study emphasizes the importance of CAE approach in optimizing EGR tube under vibrational load. EGR tube is a weak link in the EGR system and chances of failure due to vibration and relative displacement of mating parts, i.e., overhang or improper support at exhaust manifold, intake manifold, or EGR system. Consideration of the mating parts for the EGR tube is very important to get the realistic resonance frequencies, otherwise it could have some different results in the CAE, which will deviate from the reality. So, it’s important to study the dynamic response on the EGR tube, which needs to be taken care during the design phase. This paper aims to optimize the EGR tube under vibrational load by using CAE techniques and the industry experience as a product expertise. some critical parameter such as damping is very important during the CAE, which can be generated by doing the rigorous testing and how it affects the stress and correspondingly FOS. CAE model of EGR tube is created on which modal and harmonic response analysis is made. The natural frequency and stresses in the EGR tube are assessed by using CAE Tool ANSYS Mechanical. Using the CAE result observations, the changes in design of the EGR tube is done to improve its design. The design of EGR tube is improved by changing thickness, hydroformed corrugations, materials, or using different brackets. The CAE model results is also correlated with the testing results on electrodynamic shaker. EGR tube is assembled on the shaker with engine mating components having the same orientation as on vehicle. The shaker is used to find resonance frequency and to carry durability testing of the EGR tube. The results obtained from CAE model and testing are compared and found satisfactory. All the above efforts enable analysts to make the first time right design.