This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Deflection Measurement for Friction Materials Using Segment Applicator
- Ground Vehicle Standard
- J3231_202206
- Issued
Sector:
Issuing Committee:
Language:
English
Scope
This SAE Recommend Practice specifies a method for measuring the deflection of friction materials and disc brake pad assemblies in a manner more consistent with classical material compressive strain testing.
This SAE test method differs from SAE J2468 in the preload and maximum load applied to the test sample when deflection is measured. It adopts the material applied stress levels found in ISO 6310 (0.5 to 8.0 MPa) using a 25 mm diameter flat plunger.
Rationale
Legacy test methods to measure the deflection under a load of friction materials use destructive sampling to control the measurement using a known stress load. This SAE Recommend Practice addresses the brake pad deflection characteristics similar to SAE J2468, with the following refinements:
-
Use of a 25 mm diameter flat plunger to apply stress on the brake pad material applied stress between 0.5 MPa and 8.0 MPa.
-
Use of graphical and tabular formats to summarize and present the test results.
-
Inclusion of guidelines to improve the accuracy and repeatability of the test method.
-
Use of the complete brake pad assembly without the need to cut segment for testing.
The deflection characteristics of friction materials and disc brake pad assemblies are commonly used in caliper and brake system design, as well as for quality control during manufacturing. Pad deflection influences many design characteristics, including brake fluid consumption, caliper stiffness and mass, caliper piston retraction, and park brake adjustment. The deflection also influences performance characteristics including brake pedal travel, brake drag, park brake performance, and the propensity of the brake system to generate noise and roughness.
Recommended Content
Ground Vehicle Standard | High-Preload Deflection and Compressibility Test Procedures for Friction Materials |
Ground Vehicle Standard | Road Vehicles - Friction Materials - Finished Brake Pad Normalized Elastic Constant of Friction Material |
Ground Vehicle Standard | Inertia Dynamometer Rotor Crack Test Procedure for Air Disc Brakes |
Topic
Data Sets - Support Documents
No Datasets Available
Issuing Committee
Brake Linings Standards Committee
The goal of the Brake Lining Standards Committee is to provide a means of developing and maintaining common test and nomenclature standards for the friction materials industry. In working toward this goal, the committee helps reduce industry costs, harmonize global markets and enhance safety by recommending uniform test and performance standards for automotive friction materials.
Reference
Number | Title |
---|
* Redlines comparisons are available for those standards
listed in the Revision History that contain a radio button. A
redline comparison of the current version against a revision is
accomplished by selecting the radio button next to the standard and
then selecting 'compare'. At this time, Redline versions only exist
for some AMS standards. SAE will continue to add redline versioning
with ongoing updates to SAE MOBILUS.