Experimental quantification of brake factor for S-Cam type foundation brake

摘要

A new methodology for experimental quantification of brake factor (BF), in a practical way under elastic deformation, is proposed. At a newly designed testbed, foundation brake was held in brake state by a Type-24 brake chamber and then brake line pressure measurements were recorded. Simultaneously, two hydraulic cylinders in testbed were pressurized to rotate the drum against braked state of shoes. When drum starts to rotate, from all measurements, the corresponding true experimental BF quantities were obtained. In the paper, theoretical bounds were also defined. Experimental results were compared with those bounds after a weighted least squares polynomial approximation was performed on the measured data. It was investigated that significant values of BF could exceed to theoretical bounds for the certain brake line air pressure or related deformation trough stiffness effects. Therefore, the BF variation is formulated empirically as a deformation related quantity by using experimental data. (C) 2016 Elsevier Ltd. All rights reserved.