Fatigue Testing

class-img

Comprehensive Fatigue Testing Services at Westmoreland Mechanical Testing & Research

Westmoreland Mechanical Testing & Research offers bespoke fatigue testing for commercial sectors such as oil & gas, power generation, and aerospace. Our fatigue testing and analysis can prevent service interruptions, failures, and their consequences, including loss of revenue due to fatigue damage.

Contact us today for expedited fatigue testing services!

Customised Servo-Hydraulic Test Equipment and Comprehensive Testing Scope

Our unique testing approach includes an extensive scope and comprehensive data specific to each test. We can accommodate a wide range of temperatures from cryogenic to 1315.56°C (2400°F) and sample sizes from 25g (0.055lbs) to 453,592kg (1,000,000lbs).

We specialise in:

  • High cycle fatigue
  • Low cycle fatigue
  • Fastener testing
  • Fatigue testing

What Is Fatigue Testing?

A fatigue test analyses the behaviour of materials under the stress of variable loads. Typically, two loads apply to a material – a specified mass load (i.e., zero) and an alternating load. These loads cycle and measure until the material fails. This failure of a material under fatigue is called fatigue life.

Customisable Fatigue Testing Capabilities

Our substantial onsite capabilities allow us to customise each project to your materials and mechanical specifications. We provide unique customer advantages in fatigue testing:

  • Custom Analysis: We design and write proprietary software to analyse your test results.
  • Superior Turnaround Time: To ensure the best turnaround time on your projects, we design and machine specialised fixtures.
  • Customisable, Extensive Scope: For your unique testing needs we have the resources, experience, and testing capacity to get the job done right.
  • Experts in Fatigue: We are specialists in conducting axial tests on many different types of specimens.

These tests conduct load, strain, or position control on servo-hydraulic test equipment at temperatures ranging from Cryogenic to over 1315.56°C (2400°F). We have the flexibility and resources to accommodate a wide variety of sample sizes with our machine capacity ranging from 25g (0.055lbs) to 453,592kg (1,000,000lbs).

WMT&R is an industry leader in Low Cycle Fatigue (LCF) and High Cycle Fatigue (HCF) Testing for the automotive, aeronautic, motorsport, marine, ministry of defence, manufacturing, and power generation industries.

Differences Between Low Cycle Fatigue and High Cycle Fatigue Testing

Low Cycle Fatigue (LCF)

The low cycle fatigue test runs in strain control with the load being a dependent variable. The strain variables that are usually defined by the customer are:

  • Wave Shape (triangle/sinusoidal/trapezoidal)
  • Frequency (Hz, opm, strain rate = strain%/sec)
  • Maximum Target Strain or Strain Range (%)
  • A-Ratio (amplitude/mean) or R-Ratio (minimum/maximum)
  • Switch Point (Specific time or cycle at which test is stopped)
  • Discontinue Test (Specified cycle count at when reached the test is terminated)

There are three stages to low cycle fatigue testing:

  • The first stage is designed to detect crack initiation on a polished specimen.
  • The second stage is propagation life, which occurs after initiation.
  • The third stage is failure, determined by some percentage of load drop from a stable condition.

High Cycle Fatigue (HCF)

Unlike LCF, high cycle fatigue (HCF) tests conduct on specimens in force control. These tests determine the number of cycles to fracture for each specimen, and the data can compile into stress-life (S-N) curves. Nominal stress levels in HCF tests are low — significantly below the material's yield strength.

WMT&R provides high cycle fatigue (HCF) services that can help in determining the fatigue strength of a particular material through a variety of tests including but not limited to:

  • Axial Fatigue (ASTM E466)
  • 3-Point Bend Fatigue
  • 4-Point Bend Fatigue
  • Cantilever Fatigue
  • Rotating Beam Fatigue (RR Moore style)

These tests conduct at cryogenic to elevated test temperatures. WMT&R is a one-stop source for low cycle fatigue (LCF) machining, low stress grinding/polishing, and LCF testing ready to meet customers' ISO/ASTM testing requirements.

Fastener Testing

Fastener Testing directly affects every one of us on a daily basis. The cars we drive, the planes in which we fly, and the tools we use to do our work all have nuts, bolts, and fasteners. Our fatigue department is involved with a diverse array of fastener tests including fatigue tensile, wedge tensile, double shear, stress rupture, stress durability, microstructure, and chemical analysis.

Fatigue Testing Services

Our fatigue testing services include:

  • High-Cycle Fatigue (HCF)
  • Low-Cycle Fatigue (LCF)
  • Fastener Testing
  • Fracture Toughness (KIC)
  • Axial Fatigue (Displacement, Strain, Load Controlled)
  • Rotating Beam Fatigue
  • Three Point Bend Fatigue

Data reported on this test includes load peaks, strain peaks, hysteresis loops at specific intervals, calculated plastic, and elastic strain, first cycle information, and half-life cycle loop information. In addition to axial tests, we also test materials in bending and rotating modes. Bending fatigues could involve three or four-point flexural tests or cantilever fatigue tests. Rotating beam fatigues are commonly done and are available at room or elevated temperatures. Machining samples from exotic or difficult material are no problem for our in-house machine shop.

Fastener Testing is a critical component of fatigue testing that affects several sectors. From the cars we drive, the planes in which we fly, and the tools we use to do our work all have nuts, bolts, and fasteners of some kind. Our fatigue department is involved with a diverse array of fastener tests such as fatigue tensile, wedge tensile, double shear, stress rupture, stress durability, microstructure, and chemical analysis. The laboratories at WMT&R meet all the requirements of the Fastener Quality Act and its Amendments.

Do you need testing on full-size components or assemblies? We have designed and executed fatigue tests for a variety of sectors and applications including:

  • Railroad locomotive suspension springs
  • Aeronautic materials
  • Automotive components
  • Aircraft supports
  • Helicopter rotor blades
  • Coal mining equipment
  • Motorsports components

All of our tests may be run under computer data acquisition to achieve the best performance. Computer data acquisition allows us to obtain data on how a material changes in response to fatigue loading based on your particular sector applications. This data is available to you typically in a tabular data summary and as graphical representations. Due to the nature of fatigue testing, it is necessary to keep you informed as to the status of your testing.

Standardised Fatigue Testing Specifications

Here is a sample of the standardised fatigue tests that WMT&R is accredited to perform:

  • ASTM E399: Standard Test Method for Linear-Elastic Plane-Strain Fracture Toughness KIC of Metallic materials
  • ASTM E466: Standard Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic Materials
  • EN 6072: : Aerospace series - Metallic materials - Test methods - Constant amplitude fatigue testing
  • WMTR-QTP-F0281 In-house method for Rotating Bend/Beam Fatigue (based on ISO 1143)
  • ASTM E647 Standard Test Method for Measurement of Fatigue Crack Growth Rates
  • ASTM E606: Standard Practice for Strain-Controlled Fatigue
US Website

Visit Our US Website for More In-depth Testing Information

\n