Vibration Measurement On a Truck GSO Hood

A long-time customer of Dewesoft located in Greensboro, North Carolina, USA had an issue with some trucks - the hoods were cracking in the grill frame. The customer manufactures some well-known truck brands and is one of the top producers in the vocational and on-road vehicle market.

The Durability and Reliability team of the customer’s Research and Development Center conducts Track and MTS Rig testing following regulations of GCC Standardization Organization (GSO). In the field, the Hoods of some trucks had an issue with cracking in the Grill frame. Visible cracking and damage to test articles occurred during testing.

The Dewesoft SIRIUS system was applied during in-vehicle and MTS rig testing collecting the data necessary to identify the problem and potential solutions. MTS test systems are used to simulate the forces and motions in materials, products, and structures. The testing determined the problem to be the grill diagonalization.

The measurement setup was made for an on-track testing data acquisition system, including:

• SBOX data processing computer and SSD data logger

• 4x SIRIUSi-8xSTG-L2B10F with Analog Output option

• Silicon Design Accelerometers

SIRIUS systems were mounted in the passenger seat foot position and numerous sensors were positioned around the vehicle’s front end. The truck was then taken on the customer's test track to go through the custom-made events simulating field conditions. while on the track, Dewesoft recorded all the data on board the SBOX computer module.

After the Track data had been obtained and analyzed they were exported from Dewesoft to the MTS Flex test control systems and a profile was created to focus on specific events re-creating the proper Unit failure conditions.

The Dewesoft SIRIUS system provided additional signal conditioning to an MTS Flex test controller for the rig testing of possible solutions and new revisions of the hood. Converting finite-precision time series data to continually varying physical signals – and vice versa - the same signal conditioning and A/D converters were used to collect data in the rig test configuration and on the track.

Dewesoft software was used for quick visualization of the data to confirm data quality and relevance. The data was then exported to the MTS software for the rig collection. Finally, third-party software was used for detailed analysis to derive final design changes.

After extensive on-vehicle track testing and MTS rig testing the customer was able to redesign the hood structure to allow for a new grill shape. It was determined that a thicker material in certain areas would allow countering the new vibration profile to prevent any cracking on production units.