Strain and Fatigue Testing

Backed by more than thirty years of experience, and exposure to unique scenarios, ATA engineers have developed the skills and tools necessary to solve intricate and complex strength and fatigue problems. We have worked with many commercial and government customers in diverse fields including the manufacturing, transportation, aerospace, and amusement park industries.

ATA Supports Any Schedule

stress-fatigue-imgATA has a history of supporting customers with urgent and immediate needs. In addition to the flexible schedules of our engineers, our portable data systems allow us to travel anywhere in the world on short notice. ATA also has multiple data acquisition and processing systems that allow us to conduct tests for a number of different projects simultaneously.

Measurement Capabilities

instrument-imgOperational or fatigue testing often requires more than just quasi-static strain gage based stress measurements. ATA has the equipment, experience, and personnel necessary to install and measure data from strain gages, tachometers, inclinometers, displacement sensors, accelerometers, load cells, thermocouples, pressure transducers, and other instrumentation. ATA engineers are dynamics specialists – we have experience with high speed instrumentation and the subtleties involved with dynamic measurements.

Environmental Capabilities

ATA has extensive experience conducting strain tests in areas where protection against extreme environments is vital for test success. The environments we test in include: outdoors, extreme heat/cold and thermal shock, salt spray and fog, water submergence, dirty/dusty/oily environments, dynamically rough environments, low pressure and/or vacuum, and shock/explosive tests.

Data Acquisition

water-proofingATA is equipped with multiple strain conditioning and acquisition systems capable of providing quality test results in a variety of environments. Our hardware is specifically designed for environments ranging from temperature-controlled lab conditions to extreme locations where temperature, moisture, vibration, dirt, and oil would normally damage or destroy other systems. Our data acquisition systems can sample at rates over 100K samples per second simultaneously for over one hundred channels.

Fatigue Life Predictions and Operational Loads

bogey_gray_bgATA has developed a method for measuring operating loads through a structure based on strain readings and a series of strain-to-load calibrations. Using the test-measured strain-based loads and detailed finite element models, we can then provide our customers with accurate fatigue life predictions on components or in areas where strain readings are impossible to obtain.

An example in which ATA used this procedure was for a study on safety and fatigue life of rollercoaster running gear bogies. By performing a series of calibrations on the bogie, ATA characterized the load-to-strain relationship and developed a two dimensional calibration matrix. Strain data recorded during operational testing was used to resolve each of the decoupled loads. In addition to providing the customer with operating loads which would not otherwise have been measureable, ATA applied these loads to analytical models and identified several trouble areas and loading patterns, allowing our customer to optimize the bogie design, improve safety, and reduce expensive maintenance.

Dynamic Peak Stress Analysis

stress_peak_chartIn many cases it is important for our customers to understand the structural behavior of a test article during specific moments of a show, ride, or other operation. To facilitate this, ATA has developed several methods for viewing and analyzing dynamic operating measurements at discrete moments in time.

ATA test engineers can quantitatively assess overall dynamic activity using response data from a multitude of strain gages or other sensors. The method allows for the identification and accumulation of stress peaks that may contribute to fatigue or otherwise negatively impact ride comfort or entertainment value. The peaks are accumulated within short spans of time, usually 1-3 seconds each. Visualization of this data allows a fast assessment of time points which need further review in order to improve the operational performance of the structure. An example of the results is shown here.