SAE J840:2017 pdf free
SAE J840:2017 pdf free.Test Procedures for Shear Strength of Automotive Brake Pads and Brake Lining Assemblies
This SAE Recommended Practice covers equipment capabilities and the test procedure to quantify and qualify the shear strength between the friction material and backing plate or brake shoe for automotive applications. This SAE Recommended Practice is applicable to: bonded drum brake linings; integrally molded disc brake pads; disc brake pads and backing plate assemblies using mechanical retention systems (MRS); coupons from drum brake shoes or disc brake pad assemblies. The test and its results are also useful for short, semi-quantitative verification of the bonding and molding process.
This Recommended Practice is applicable during product and process development, product verification and quality control.This Recommended Practice does not replicate or predict actual vehicle performance or part durability.
The purpose of this test is to quantify the load required to cause a shear failure at the interface of the friction material and backing plate or brake shoe. The test also provides a qualification of the failure mode on the assembly at the different layers or components. Test parts can be of different types and in different conditions: new or used from vehicle or inertia-dynamometer test, prototype or production, complete assemblies or segments, and with or without special treatment like thermal, environmental or corrosion exposure.
Use a movable ram that contacts the edge of the lining for its full length and thickness within 1 mm ± 0.2 mm (0.040 inch ± 0.008 inch) of the shoe table or rim; See Figure 1. The ram shall contact the lining on its entire width in the direction of the shear load. Apply the load in a direction perpendicular to the plane of the shoe web; support the shoe to maintain uniform loading along the length of the lining or segment; avoid distortion of the shoe table or shoe web during the test.SAE J840 pdf free download.
