Tyres | Buying Guide | Technology | Size Guide | Speed Rating

Cooper Tyres Technology

Cooper engineers work in teams with our customers to design advanced systems for our customers' specific needs. We are proud of the work we do with our customers, and are aggressively expanding our capabilities with new systems for Computer Aided Design, Computer Aided Engineering, vehicle testing, and rapid prototyping. In addition, we have recently added a new technical centre located at our Auburn, Indiana, campus. At each of our design facilities, we have a talented staff of dedicated people using a number of techniques to solve design problems.

Vehicle Analysis

Our vehicle analysis techniques have helped us obtain useful information for improving our product designs and their performance on vehicles. Test vehicles are outfitted with a microprocessor based on-line vehicle modal characterization computer. Random or repetitive excitations are input onto the vehicle structure, either from the engine or a computer controlled shaker rigidly attached to the structure.

  Frequency response functions are measured at predetermined performance points, usually the steering wheel, seat track and floor pan. Sound pressure levels at peak frequencies are also measured. The data obtained is used to evaluate and verify the effectiveness of the powertrain components and other vibration isolators, and for subjective Noise Vibration Harshness evaluation.

Data obtained from vehicle modal analysis is input into the SMS (Structural Mode Shapes) software. Structural animation of mode shapes at peak frequencies establishes the active locations on the structure and conditions under which the dominant activities occur. This information is used to establish the optimal placement of vibration isolators.

Fatigue Validation

For fatigue validation, an on-line data acquisition system is used to monitor conventional passive vibration isolators undergoing bench tests. The criteria for the tests (load, displacement and elapsed time) are preset on the machine for the test's duration. The system tracks specimen conditions and shuts down the test equipment if any of the presets are violated, or when the test has run its course.

State of the Art

New equipment has been acquired with the same capabilities as our multi-axis tester, but with the following additions:

• Ability to fatigue test in three directions simultaneously.
• Part characterization software that allows static and dynamic performance tests at specified fatigue life cycle intervals without removing the part from the equipment.
• Programmable environment chambers for cold and hot temperature tests.
• Signal Processing Interactive Data Analysis Routine (SPiDAR) simulation software, which provides iterative control for testing including partial spectral analysis and drive profile generation.

Specialized equipment is used for studying heat build-up in the elastomers during testing. The heat distribution pattern is used to determine the failure mode of the test specimen. This information can then be used to redesign parts that fail prematurely due to excessive heat build-up The same equipment can also be used to determine heat distribution in a mould during warm-up and during the actual part moulding operation. This information is useful in uncovering any potential process problems, such as inadequate heat distribution in mould cavities.

Performance Validation

Our computer controlled elastomer test system is used to validate load/deflection characteristics of vibration isolators in tension or compression. Test criteria are entered prior to testing. Graphical results are then stored to disk or printed for statistical analysis. Test results are then used to validate the results obtained from design optimisation software.

Finite Element Analysis

Cooper's Engineered Products Division also uses Finite Element Analysis (FEA) during the design process to improve and speed up part design.

Typical analysis work we have performed includes (but is not limited to):

• Linear and non-linear dynamic and static analysis.
• Harmonic analysis of pre-loaded assemblies to simulate actual service performance.
• 2D and 3D contact analysis to simulate and evaluate contact forces (body seals).
• Accurate calculations of shape factors for fine-tuning our design and elastomeric assemblies.
• Fracture mechanics and fatigue-life evaluation to simulate durability tests. We have access to a Scanning Electron Microscope and we use the facilities to examine the modes and mechanisms of failure from fractured surfaces obtained from durability tests or actual failed parts.
• Validation of experimental test results from analysis of test sample models.

Tyres | Buying Guide | Technology | Size Guide | Speed Rating