Application of Alternative Methodology to Select the Optimum Design of TCU Carrier Using FEA

The transmission control unit is used in automobile domain, to control the automatic transmissions. TCU is associated with mechanical parts like Housing, Carrier, Hydraulic Plate etc. In this case, TCU carrier is mounted on hydraulic plate using a dowel pin to locate it accurately. During servicing of the TCU, Carrier with dowel pin is subjected to high displacement which leads to huge plastic deformation & failure of the carrier. A study was required using Finite Element Analysis for a series of designs to evaluate their structural stability and to recommend the best possible design. ANSYS tool is used for the simulation. During this study, when conventional method of reckoning stresses and strains as a criterion of comparison was adopted, it involved a tedious process & required many numbers of iterations. Despite plenty of iterations, it may not be possible to conclude the exact force at which the carrier fails or the max displacement it can withstand. The other reason to look for an alternative method is, the development team expectations about the structural stability of the carrier considering operating conditions is contradicting with the strains observed with conventional method. So, there was a need to develop alternative method to evaluate the carrier strength. Hence, stiffness criterion is obtained as a solution. Series of designs are compared based on stiffness & deformation criterion for loads ranging from operating load of 3 mm to maximum displacement load of 6 mm. The simulation results through this stiffness method obtained are also validated with testing results and accuracy of results is observed. This study using stiffness method helped us in selection of best possible carrier design suitable for maximum displacement load without any failure. Cost of testing for around 6 designs is reduced by using FEA and optimum design is also obtained.