GMW17887

Description / Abstract: Introduction

Note:Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose.

This procedure evaluates the structural durability performance of damper modules when subjected to real-time load profiles simulating proving ground road durability tests. This procedure describes developing the test and performing the durability test execution.

Note: If the strut tower and/or the surrounding structure are included in the evaluation requirements, this test procedure can be executed in conjunction with GMW17058 (Strut Tower Strength and Durability).

Applicability.

This procedure is used to develop or validate the structural durability of a damper module. Damper module components that are not sensitive to fatigue damage from road inputs may not experience the same level of correlation.

This procedure does not provide a total damper module durability test. Only vertical inputs are driven into the damper module test system. The resultant lateral forces are not used for test development or correlation, but will be monitored.

This procedure applies to all independent suspensions provided that the test system has the capacity to reproduce the suspension road responses. Refer to Table B1 in Appendix B for typical test system configurations and specifications.

Remarks.

This procedure simulates road induced loading, using repeatable displacement profiles, designed to represent durability modules that make up the proving ground road durability tests. The loads cause fatigue and wear phenomena on the damper assembly.

The typical test process diagram for performing a damper module fixed reacted, real-time, laboratory road simulation structural durability test and test development is in Appendix A, Figure A1.

This procedure reproduces the test equivalent of fatigue exposure, for most vertical structural inputs, in less time than it takes to perform an equivalent proving ground road durability test, (reference 3.4 for test time estimates).

Typically, for each test request, a Road Load Data Acquisition (RLDA) or Virtual Road Load Data Acquisition (vRLDA), a drive file development, and a correlation evaluation are performed.

This procedure refers to other procedures which contain detailed information that is closely tied to specific equipment or software. These procedures were specifically written for full vehicle, inertia-reacted, laboratory road simulation testing, but are also applicable to this procedure. Refer to 2.2 for the list of GM documents referenced in this procedure.

This procedure is written as a guide for engineers and technicians. It does not cover every possible aspect of a damper module, fixed-reacted, real-time, laboratory road simulation structural durability test. This procedure is intended to produce a laboratory road simulation for a specific damper module. That is, a set of drive files will closely reproduce measured responses obtained from remote parameters and correlation transducers for a damper module with a specific combination of ballast condition and suspension components. If any of the component characteristics are changed from the damper module used to collect the road load data, the degree of laboratory to road correlation may be reduced. For further details see 7.3.1.