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Interface Specializes in Fatigue-Rated Load Cells

Often test protocols require a fixed load plus a dynamic load to be applied to a test sample simultaneously. Interface Fatigue-Rated Load Cells are well suited for this requirement. Fatigue-rated is a specification that defines a special class of load cell design and construction used for repetitive cycle and fatigue testing.

Interface has specialized in fatigue-rated load cells and their applications since our founding in 1968.  The stringent discipline that is necessary to produce true fatigue-rated load cells, with consistency, is why Interface is known for this specialized load cell design and construction.

Manufacturing these special types of load cells, we can proudly state there is no record of reported fatigue failure for Interface Fatigue-Rated Load Cells used within their specified ratings. Interface fatigue-rated load cells have a given service life of 100 million fully reversed, full capacity loading cycles. It’s why reliability, durability, and quality rank these types of load cells as best-in-class for fatigue and cycle testing.

The use of fatigue-rated load cells and data logging instrumentation are used for testing materials, parts, or assemblies for weakness, and often ultimately to destruction. These types of fatigue tests are valuable to have an accurate record of the forces applied at every moment of a test to analyze stresses, identify fatigue and potential failure risks.

INTERFACE FATIGUE-RATED LOAD CELLS:

  • 1000 Fatigue-Rated LowProfile® Load Cell Model 1000 series is a fatigue-rated low profile load cell with 300% safe overload, extremely low moment sensitivity of 0.1%/in and a higher fatigue life. Capacities give you options to measure 1 pound (4.45N) and up to 1 million pounds (4500kN) of force.
  • 1000 High Capacity Fatigue-Rated LowProfile® Load Cell With many variants and configurations our fatigue-rated load cells provide up to 100 million fully rendered cycles. The gaged sensors in every load cell are individually inspected, tested, and certified to meet our rigid standards.
  • 1500 Low Capacity LowProfile® Load Cell – The Interface Model 1500 is a fatigue-rated unique LowProfile Load Cell designed for low capacity applications where low sensitivity to eccentric load is important.

Each fatigue-rated load cell model grouping also has numerous capacities and variations, including additional bridge options. All product variations, capacities, customization options and availability are online. There are possibilities to have engineered-to-order made products and customized solutions, as with all Interface manufactured load cells.

When passing fatigue testing is critical to the success of an assembly, piece of equipment or product, engineers and manufacturers rely on Interface Fatigue-Rated Load Cells. Our fatigue-rated load cells are used by most manufacturers of test machines, aircraft, spacecraft, auto and transportation vehicles, and various devices and industrial systems.

Here are a few fatigue-rated applications that demonstrate different use cases:

Furniture Fatigue Cycle Testing App Note

Bike Frame Fatigue Testing App Note

Aircraft Wing Fatigue App Note

Prosthetics Load and Fatigue Testing App Note

Additional reading on this subject can be found here in the post, Considerations for Fatigue-Rated Load Cells. If you are exploring fatigue-rated load cells or products for cycle testing, contact our application engineers to answer questions and ensure you get the right product for your testing needs.

Interface Plays a Role in Testing Bicycles

Interface sensors are used in a never-ending list of products, from heavy machinery to miniature medical devices. In the spirit of the Olympics, we thought we would share how our force and torque technologies are used in the test and measurement of bicycles, whether used for extreme off-road racing or speeding around the track. Interface has a role in helping to get bikes on the road and performing at optimum speeds.

Road, mountain and e-bikes present a fantastic use case for our products because everything from the force a rider puts on a bike’s suspension, shocks and frame when sitting on it, to the torque of the pedals and tires need to be carefully tested before a bike is ready for action. In the application notes below, we outline different parts and kinds of bikes that utilize measurement testing in design and actual use, along with the specific Interface force sensors used in each case.

Mountain Bike Shock Testing

In this application example, when a manufacturer wanted to test the durability of the forks on the front of their bikes, the rear shocks, front suspension, and ensure that the bikes shocks absorption is working properly for bike riders, we had a solution. Interface suggested installing the 1000 High Capacity Fatigue-Rated LowProfile™ Load Cell in a fatigue frame using the company’s bike forks. The forks undergo a fatigue test for several hours. Test results from the 1000 High Capacity Fatigue-Rated LowProfile™ Load Cell will be sent to the INF-USB3 Universal Serial Bus Single Channel PC Interface Module where the customer can view, log, and graph the results on their PC computer or laptop with provided software. Using this solution, the customer was able to test the bike’s front and rear shocks using Interface’s products. They determined if there were any weak spots in the forks or if it was working properly.

E-Bike Torque Measurement

e) manufacturer needed to test the torque on their electronic bicycles. They also needed a torque sensing system that measures how much force the bike rider is pedaling onto the pedals, because this determines how much electric power the bike’s motor generates. To address this challenge, Interface suggested installing the Model T12 Square Drive Torque Transducer where the pedal assist sensor would normally be. The T12 Square Drive Torque Transducer’s results could then be recorded, graphed, and logged using the SI-USB4 4 Channel USB Interface Module when connected to the customer’s PC. This allows the e-bike manufacturing company to successfully test the torque on their electronic bicycles with Interface’s products and instrumentation.

Bike Power Pedals

For a bike manufacturer testing the functionality of its power pedals, Interface supplied a full wireless system solution to measure how much force the cyclist pushes down onto the bike pedals. The solution included four Model SML Low Height S-Type Load Cells installed within the bike’s pedals. The four SMLs were paired with our Wireless Telemetry System components, two WTS-AM-4 Wireless Strain Bridge Transmitter Modules, which transmit the force data from the cyclist to the WTS-BS-6 Wireless Telemetry Dongle Base Station Dongle connected to the customer’s PC or laptop. Interface also provided the software needed with their wireless products. Using this system, the bike manufacturer was able to measure the pedal power applied by the cyclist. The customer was also able to measure and log the data wirelessly transmitted to their PC computer.

Bike Load Testing

In this example, another mountain bike manufacturing company wanted a system that measures their bike frames load capacities and vibrations on the frame, and to ensure the bike’s high quality and frame load durability during the final step of the product testing process. Interface suggested installing Model SSMF Fatigue Rated S-Type Load Cell, connected to a WTS products, the WTS-AM-1E Wireless Strain Bridge, between the mountain bike’s seat and the bike frame. This measured the vibrations and load forces applied onto the bike frame. The results are then captured by the WTS-AM-1E and transmitted to the customer’s PC using the WTS-BS-6 Wireless Telemetry Dongle Base Station. Using this solution, the mountain bike manufacturing company was able to gather highly accurate data to determine that their bikes met performance standards through this final testing.

Bike Frame Fatigue Testing

Fatigue testing is critical for bike design engineers. Our customer wanted to perform a fatigue test on their bike frames and analyze the strength of their bike frames in order to ensure durability and high-quality standards, turned to Interface for a solution. We suggested installing Model 1000 Fatigue-Rated LowProfile™ Load Cell to the customer’s bike frame fatigue tester. This load cell provides the customer with highly accurate results through the fatigue cycling. These results are collected using the INF-USB3 Universal Serial Bus Single Channel PC Interface Module and displayed on the customer’s PC or Laptop with Interface’s provided software. With this solution, the bike manufacturing company successfully had their bikes undergo fatigue frame testing, receiving highly accurate results with Interface’s load cell and instrumentation.

This deep dive into bicycle testing is just the beginning in demonstrating how many applications of Interface products can be used to improve the quality and reliability of the final design. When you consider bicycles, testing is critical whether it’s being used in the Olympics, for recreation or even transportation. Bicycle safety is fundamental to any design. Testing the performance and durability are essential before any bicycle is approved to be used on the road.

For a preview of all the application we have and can possibly work on, continue following the Interface IQ Blog at http www.interfaceforce.com/blog/. Each month we provide analysis and insight on new and interesting use cases and application examples.