Integrated Structural Durability Test Cycle Development for a Car and its Components

This work was taken up with the objective of developing an integrated durability test cycle for a car and its components applicable for Indian service usage of 1,60,000 kilometers. The test cycles applicable for following test facilities have been developed.

• In-house durability track testing for vehicle durability
• 4 poster durability tests on vehicle
• Component durability tests on suspension test rig

The service road load data was collected for two different types of service usage:

• A car running long distances on wide variety of roads which include highways, rough roads, city streets and so on. The damage due to road inputs in such a usage is of continuous nature.
• Car usage on various vehicle driving situations akin to Indian service conditions such as pothole braking or a speed-breaker braking. The road inputs in such events on a car are of short duration but are of very high magnitudes (shock loads).

The correlation of these road inputs in these service usages in the test cycles has been done using following techniques:

• In-house durability track testing: Match of exceedance plots of service loads and test loads using correlation techniques from principles of linear regression.
• Simulation on 4 poster and suspension test rig using iterative remote parameter control technique.

Severity match on the above test cycles has been fully achieved as the part failures have exhibited good match between the service use and tests for the failure modes and life.

Use of the integrated approach to develop test cycles for complete vehicles and its components based on common road load inputs in reducing developmental costs has been successfully demonstrated for suspension components validation during development of this car.