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Structural durability of different components and systems for a Utility Vehicle is critical to design, due to severe customer usage in rural zones and off road driving conditions. Physical validation of new component designs is time consuming, costly and iterative. Also, this process does not ensure an optimized structure. Through virtual validation it is possible in the initial phase of design to validate the structure and optimize the design. The core of a virtual validation process is to obtain accurate correlation which can replace developmental laboratory testing. Hence, only a confirmatory test can be carried out. This enables design optimization based on simulations. This paper presents the systematic approach used for optimization of SUV rear bumper and bumper mounting structure. Dynamic correlation is obtained for bumper structure subjected to the vibration levels as mapped from the proving ground test. The objective of new bumper development is for value engineering.

The cylinder block for the power train has always been a classic example of concurrent engineering in which disciplines like NVH, Durability, thermal management and lubrication system layout contribute interactively for concept design. Since the concept design is based on engineering judgment and is an estimated design, the design iterations for optimization are inevitable. This paper aims at outlining a systematic approach for design of crankcase for fatigue which would eliminate design iterations for durability. This allows a larger scope for design improvement at the concept stage as the design specifications are not matured at this stage. A process of stress optimization is adopted which gives accurate dimensional input to design. The approach is illustrated with a case study where an existing crankcase was optimized for fatigue and significant weight reduction was achieved.

With the increasing demand for light weight engines, the design of FEAD (Front end accessory drive) Brackets has gradually shifted from conservative cast iron design to optimized aluminum design. Hence there is a requirement for a virtual validation procedure that is robust and accurate. The FEAD brackets for the engine are subjected to periodic vibrations (engine excitations) and random vibrations (Road excitations), the former being the more dominant of the two as road excitations are isolated by the power train mounts. Hence these brackets are susceptible to fatigue failures. The paper describes a virtual validation procedure adopted for FEAD brackets that gives accurate stress prediction and thereby ensures accuracy in predicted fatigue factor of safety for design. The simulated dynamic stresses are later compared with the test results and a good correlation is observed.