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Interface Solutions for Structural Testing

Interface products are used in many types of structural tests across industries, including for rockets, aircraft, EV batteries, heavy equipment, and infrastructure projects. Our loads cells provide the accurate and reliable data, which is why our force measurement solutions are a top choice for these complex and highly regulated industries.

Structural testing labs use Interface solutions to perform tensile, compression, bending, fatigue and hardness testing on materials, components, or assemblies. There are a variety of structural tests used for measuring tension of push and pull forces, design proofing, and lifecycle fatigue validation. Each of these tests plays a critical role in verifying the quality and safety of a product, component or materials, and each of these tests relies upon force measurement sensors.

Types of Structural Testing

  • Tensile Testing involves applying a pulling force to measure a structure’s strength and resistance. Load cells are used to measure the applied force and resulting tension from elongation or deformation of the material.
  • Compression Testing uses compressive force to evaluate the strength and resistance of a structure to crushing. Force measurement sensors are used to measure the magnitude of the applied force and the resulting deformation or failure.
  • Torque Testing measures the twisting or rotational forces applied to a structure. Torque transducers are utilized to assess the material’s torsional strength, stiffness, and behavior.
  • Load Capacity Testing determines the maximum load that a structure can withstand before failure. Force measurement sensors and load cells are used to gradually increase the load until failure occurs, enabling the determination of the structure’s load-carrying capacity.
  • Bending Tests assess the flexural strength and behavior of materials under force. Load cells measure forces applied during bending and to determine the bending moment, stress distribution, and deflection of the material within a structure.
  • Fatigue Tests in structural testing labs assess the durability and performance of materials under cyclic loading conditions. Force sensors measure the applied forces or loads helping to analyze the material’s fatigue life through various cycle counts.
  • Impact Testing involve subjecting a structure to sudden and high-intensity forces to assess its ability to withstand rapid loading conditions. This is particularly important for environmental condition testing to structures that endure extreme temperatures, winds, moisture. This type of testing is also important for submersible structures.
  • Shear Testing evaluates the resistance of a material to forces applied parallel to its surface, causing it to slide or deform. Force measurement devices measure the applied shear forces and determine the shear strength and behavior of the material used in a structure.

During the Testing Lab Essentials Webinar, Interface application experts detail various ways our products serve test labs. During this event, the experts detailed top considerations in selecting Interface products that serve test lab engineers in conducting structural tests. 

Structural testing labs use our LowProfile load cells because they are designed to fit into tight spaces and machines, making them ideal for use in small-scale structural applications. High-capacity load cells from Interface are designed to measure large forces and are commonly used in heavy machinery and structural testing. Universal load cells are capable of measuring tension and compression, making them ideal for quality control and structural testing applications.

Multi-axis sensors are valuable force measurement solutions as they provide more data across two, three and six axes during a single structural test. Implementing multi-axis sensors can provide a more complete picture of loads and moments being applied to the DUT providing additional insight for design and verification.

As noted in the webinar, key challenges involved in structural testing include managing and isolating extraneous loads such as off-axis load and bending, understanding which products are most suitable for the type of structural tests you are performing and ensuring the instrumentation you are using is compatible with force solutions. Equally, it is important to define your systems for optimal data collection in the planning phase of any project.

Structural Testing Applications

Performance Structural Loading

Performers and entertainers have special stages built to perform in concerts for their fans. From the largest sports events half-time shows to other complex staging, a force measurement system is needed to ensure the safety for all performers, equipment, and scenery on stage. The stage needs to hold all weight, and also maintain during dynamic movements, such as performers walking on stage. For this challenge, Interface’s A4200 Zinc Plated or A4600 Stainless Steel WeighCheck Load Cells paired with the 1280 Programmable Weight Indicator and Controller is able to measure the individual loads on each load cell, or the entire weight of the performance stage. Results from the 1280 Programmable Weight Indicator and Controller was sent to the customer’s control center. Using Interface’s A4200 Zinc Plated or A4600 Stainless Steel WeighCheck Load Cells as a customizable solution, the customer was able to monitor and weigh the performance stage.

Rocket Structural Test

NASA’s Space Launch System (SLS) core stage will be the largest ever built at 27 feet in diameter and 200+ feet tall. Core components including liquid hydrogen and oxygen tanks must withstand launch loads up to 9 million pounds-force (lbf). Interface load cells attached to hydraulic cylinders at various locations along test stands to provide precise test forces. Strain gages bonded to rocket structure surface and connected to data acquisition system for stress analysis. Using this solution, Engineers are able to measure loads applied at various areas on the rocket structure, verifying the structural performance under simulated launch conditions.

EV Battery Structural Testing

As electric vehicles push advancements in efficiency gains, structural battery packaging is at the forefront for optimization. This drives the need to validate structural battery pack design, both in terms of life expectancy against design targets as well as crash test compliance and survivability. Interface’s solution includes 1100 Ultra-Precision LowProfile Load Cells in-line with hydraulic or electromechanical actuators in customer’s test stand. Also utilized are 6A Series 6-Axis Load Cells to capture reactive forces transmitting through pack structure. Multi-axis measurement brings greater system level insight and improved product success.

Interface is a valued partner to test labs for providing solutions for structural testing.

Additional Resources

Modernizing Infrastructure with Interface Sensor Technologies

Rocket Structure Testing

Rigging Engineers Choose Interface Measurement Solutions

Load Cell Selection Guide

Types of Force Measurement Tests 101

There are distinct types of force tests that engineers, product designers, manufacturers, and test labs perform to accurately measure factors that control quality, safety, and reliability.

Testing force helps to qualify how something will react when applying load, either by a normal application or by pulling and pushing it fails. The type of force measurement classifications are compression, fracture, tension, flexure, and shear.

Interface provides a broad range of solutions for static and dynamic force measurement tests including standard and custom transducers, instrumentation, accessories, frames, calibration equipment and other components used for in force testing.

The most common categories of force testing include:

  • Tensile testing
  • Shear testing
  • Compression testing
  • Fatigue testing
  • Torque testing
  • Hardness testing
  • Static testing
  • Mechanical strength testing
  • Material testing
  • Proof load testing
  • End of line testing

There are variations to each of these test classifications, such as cycle testing is often a subset of fatigue and mechanical strength tests. Hardness testing is frequently referred to as nondestructive testing. Initial R&D tests typically center around choosing materials, strength and durability tests, compression ergonomic and abrasion tests.

Here are the general characterizations of the most popular types of force tests.

Tensile Test

Tensile strength is the ability of a metal to withstand a pulling apart tension stress. Performing a tensile test, sometimes referred to as tension testing, applies uniaxial load to a test bar and gradually increasing the load until it breaks. The measurement of the load is against the elongation using an extensometer. The tensile data is analyzed by using a stress-strain curve. Interface load cells are commonly used for various tensile tests when accuracy of measurement matters.

Compression Test

Compression is the result of forces pushing towards each other. The compression test is like the tensile test. Place the object in a testing machine, apply a load and record the deformation. A compressive stress-strain curve is drawn from the data. Interface provides load cells that measure compression-only or tension and compression measurements from the same device.

Torque Test

Torque measurement determines how an object will react when it is turned or twisted. There are two common use cases, fastening tests of objects or by testing rotating parts in an assembly. The two types of torque measurement are reaction and in-line, which are important when selecting the type of torque transducer to use in your test. The wrong torque can result in the assembly failing due to several problems, whether that is by torque testing bolts or engine parts. Parts may not be assembled securely enough for the unit to function properly, or threads may be stripped because the torque was too high, causing the unit to fail. Torque is a force producing rotation about an axis. This type of testing is also extremely popular in automotive to measure a variety of components.

Shear Test

Shear strength is the ability to resist a “sliding past” type of action when parallel, but slightly off-axis, forces, applied in the test. Shear force is directional force that is over the top of a surface or part. Shear is measured by tension or compression using a shear or bending beam load cell.

Hardness Test

Hardness testing, which measures the resistance of any material against penetration, is performed by creating an indentation on the surface of a material with a hard ball, a diamond pyramid or cone and then measuring the depth of penetration. Hardness testing is categorized as a non-destructive test since the indentation is small and may not affect the future usefulness of the material. There are a wide variety of hardness testing types as well.

Examples of Testing Types

Compression Test Example

Interface’s customer wanted to measure the amount of compression force a piece of candy could withstand to ensure its label is marked correctly. The purpose of the test was to correctly calibrate the equipment to provide the same stamping force each time without breaking the candy apart. An Interface Model WMC Mini Load Cell and 9330 Battery Powered High Speed Data Logging Indicator are used to measure the results. Read more about this compression test here.

Torque Measurement Example

In this example torque testing accurately measures the forced needed to securely fasten a bolt. This type of test is critical in highly regulated industries like aerospace and automotive to ensure every screw and bolt are not over or under-tightened. Interface’s LWCF Clamping Force Load Cell along with Interface’s INF-USB3 Universal Serial Bus Single Channel PC Interface Module provide a solution that monitors the force being applied during bolt tightening.

Shear Test Example

This example shows how aerospace manufactures use shear testing to measure the affects of wind as it moves past the wings, hull, and other components of a plane. Interface measured this force using a Model 6A154 6-Axis Load Cell mounted in the floor of the wind tunnel, and connected  to the scaled model by a “stalk”. A BX8-AS Interface BlueDAQ Series Data Acquisition System was connected to the sensor to collect data.

As products become more complex and technologically advanced, the test and measurement industry must provide solutions to monitor a wide variety of factors. This is no different in force measurement.

Interface has been involved in every type of force measurement type across a variety of applications both large and small. To learn more about our more than 36,000 product SKUs designed to conduct all these tests, from single load cells and torque transducers to complete testing rigs and systems. We also provide calibration services for all types of force measurement transducers. Contact us if you are unsure which force measurement solution best fits your testing plan.

Additional Resources

Tensile Testing for 3D Materials

Material Tensile Testing

Interface Solutions for Material Testing Engineers

Bike Handlebar Fatigue Testing

Interface Specializes in Fatigue-Rated Load Cells

Specifying Accuracy Requirements When Selecting Load Cells

Spring Compression Testing App Note

Insights in Torque Testing Featured in Quality Magazine