scope:

Purpose.

To test a vehicle for self-induced stone impact damage. Areas of the vehicle that are susceptible to stone impacts shall be identified and any changes that are needed to the styling or components shall flow into the development process at an early stage.

Four (4) testing options are available and described in the following document. Each individual testing option does not necessarily need to be performed. The test options can be executed on an as-needed basis. The following summarizes the four options:

Total Vehicle Analytical Evaluation (Math Based).

The stone impingement performance of a vehicle is influenced by its surface geometry due to the impact angles with which a stone impinges the vehicle surfaces. To better understand the vehicle's performance prior to any physical properties being available, a math-based tool can be used to evaluate the impinged surfaces. Modifications to the vehicle can then be made prior to a design freeze for the vehicle.

Exterior Styling Concept Development (Road Based).

Stone impact damage to the lower exterior surfaces (fenders, quarter panels, doors, etc.,) can lead to customer complaints or, in extreme cases, to cosmetic corrosion and thus to loss of vehicle value. The development test, therefore, serves to influence the outer shape of the vehicle. (The test results shall be available before styling freeze.) For this test the outer skin of the susceptible stone impact areas is fitted to a mule vehicle to evaluate the stone impact behavior and potentially optimize the styling of the vehicle. These results shall be able to be used to prevent directly visible stone impact damage for customers.

Underbody Development (Road Based).

The objective is to evaluate stone impact damage to the underbody structure or underbody components that could lead to cosmetic corrosion or functional issues.

Total Vehicle Validation (Road Based).

During the validation test, a production-process built vehicle or a vehicle built that is deemed sufficiently representative of the design and production processes is evaluated for the following:

Exterior stone impact damage that is visible and may be objectionable to critical customers.

Underbody stone impact damage that may lead to corrosion or functional issues.