Agricultural Tractor Hydraulic Lift Arm Assembly Design for Durability and Correlation with Physical Test 2016-28-0237

A hydraulic power train assembly of an agricultural tractor is meant to lift the heavy implements during field operations and transportation. As it is a crucial member of the tractor for its usage, so the power train assembly needs a properly designed lift arm, rocker arm assembly with better strength and stiffness. There are a standard like IS12224, IS4468 which regulates the test method for hydraulic power and lift capacity of tractor and the layout of hydraulic three point linkage. Computer aided engineering techniques followed by laboratory testing have been deployed in the earlier stages of the product design & development itself to deliver the first time right products to the customer.

In this paper, a virtual simulation process has been established to design an agricultural tractor hydraulic lift arm to meet the above requirements. A Design Verification Plan (DVP) has been developed consisting of 3 load cases. Loads and boundary conditions have been arrived based on the RWUP data from the field. Design acceptance criteria have been formulated for clearing the hydraulic power train assembly test as per IS12224, IS4468 and durability for the tractor life. Virtual validation has been done by performing (i) A multi body dynamics analysis to study the dynamic behavior of interconnected rigid or flexible bodies; MBD approach is used to predict the loads on Tractor Hydraulic Lift arm and (ii) Static structural analysis in ABAQUS for the durability. In hydraulic power train test, equivalent plastic strain approach has been used for predicting the failure and for durability analysis, fatigue based approach has been used for the life estimation. Physical test has been done in the NABL certified in-house lab for the hydraulic power train assembly and has been correlated with the CAE results. In this work, 94.6% of correlation between Virtual and physical test has been achieved.