Objective: Friction materials (FMs) are normally tested in brake inertia dynamometers (dyno) for validations & approvals before introduction in the market. Dyno testing can be expensive, time-consuming, and needs infrastructure, energy, and manpower to operate. Apart from this, other testing methods using full-scale non-inertia rigs (Quality testers), and sub-scale testers like FAST and CHASE testing are used in the friction industry. In a quest to save energy and time of dyno testing for quicker screening and validation, a new performance schedule was designed & validated on our non-inertia full-scale rig and compared against the inertia dynamometer outcomes. Methodology: Two different types of friction materials (NAO & Low-met) were chosen for this case study. Our Simulated Performance Test (BI-SPT) schedule was designed based on global performance test standards of SAE J2522 (AKM) and ISO-26867 test schedules, with a short time duration of 3.5-4.0 hours in the non-inertia full-scale rig. The same friction material grades/brake was tested on the inertia dynamometer with the regular AKM and ISO schedules as well. Results: It is observed that the repeatability of the SPT schedule on the non-inertia rig was within 2% for both grades. the tested NAO & Low-met grades show a good correlation with the inertia dyno results on a qualitative basis (coefficient of friction behavior). Non-inertia rig results also correlate well on the Mu behavior with the different sections of inertia dyno test standards. Conclusions: Our results from BI-SPT run on a non-inertia test rig can be used as a time & cost-effective test method for initial assessment during formulation development, raw material screening, process, and quality verifications. Overall, this helps in quicker developments with only validations performed on the inertia test rig.
Dr. Mukesh Kumar, R&D Manager, Brakes India Private Limited; Mr. Srikanth Venkatesan, Friction Business Head, BRAKES INDIA PVT LTD; Mr. Hariharan Swaminathan, Chief Friction Formulator, BRAKES INDIA PVT LTD; Mr. Venkatraman Gopalakrishnan, Senoir Manager, BRAKES INDIA PVT LTD