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Every class of commercial vehicle has an entirely different usage pattern based on customer application and needs. To perform accurate durability testing, these prototypes should run on real customer usage locations and loading conditions for the target life. However, this is time consuming and not practical, hence resulting in Proving Ground (PG) testing. It is also known that a standard PG durability cycle cannot be valid for every class of vehicle and every application. So a statistical approach was followed to develop an accelerated durability test cycle based on in-house PG test surfaces in order to match the real customer usage to the durability target life. This paper summarizes the methodology to develop Durability Validation test cycles for commercial vehicle based on the work carried out on a heavy duty tipper and an intermediate commercial vehicle.

The use of Wheel Force Transducers (WFTs) to acquire data for laboratory simulation is becoming standard industry practice. However, in test rigs where we have only the suspension module and not the complete vehicle, does the reproduction of the orthogonal forces and moments at the wheel centre guarantee an accurate replication of the fatigue damage in the suspension components? The objective of this paper is to review the simulation methodology for a highly non-linear suspension in a 3 DOF (degree-of-freedom) suspension test rig in which the simulation was carried out using only the three orthogonal loads and vertical displacement. The damage at critical locations in the suspension is compared with that on the road and an assessment of the simulation using the WFT is made based on a comparison of the damage on the road vs. the rig.

Often complete vehicle, aggregate and component fatigue testing in the laboratory is conducted using one specific field or track recording of pre-selected vehicle component response data. These data become the targets which are reproduced in the laboratory with various test methods. These data are usually edited using various accelerated test methods to achieve shorter test time. The final drive signals at the minimum error condition are used to conduct the durability test on the vehicle. The fatigue failures that are obtained in the laboratory test could be biased due to the limited data set. A study was carried out where data were collected using multiple drivers and multiple repeats from the same test tracks. Multiple sets of component and aggregate response data were analyzed in terms of damage and other fatigue related properties. In practical engineering situations it is not possible to collect such large volumes of data.

In this paper the authors report on a development at Bharat Forge where CAE tools are an integral part of the new physical test laboratory. The paper will show how CAE can be used to model the physical test process and create its own “virtual test” process. By using these tools in parallel and by validating the virtual process at each stage of the test process, confidence is gained in the virtual process. The goal is to integrate the virtual test process into the component design process to establish an early validation of the component prior to finalizing the dies and forging the component.

Model-in-the-loop (MiL) testing refers to the scenario in which the test specimen is part real and part virtual, i.e. a physical sub-system is linked to a real-time computer simulation. Due to imperfect actuator behavior the hybrid test specimen will not respond in quite the same way as the real (complete) specimen would. In this paper the accuracy of the MiL system is assessed for two automotive testing examples: tire vertical dynamic emulation, and the emulation of aerodynamic forces. Linear models of racecar dynamics are used in the assessment, combined with real measurements of actuator response. The results indicate that considerable care is required in designing such test systems; the tire emulation results in particular are unacceptable.