Structural Durability & Fatigue Testing

Structural durability/fatigue testing is performed by subjecting a test sample to the load conditions it will experience during its service life. This testing is typically performed early in the product development process to identify design deficiencies prior to releasing the product for production. It is also commonly used as a validation test for component selection or product design. 

 

Traditionally, the structural durability of a product is assessed by building and testing full-scale prototypes and operating them under typical conditions. Although effective, this approach can be costly in the fabrication and operation of a full-scale prototype machine. To allow for adequate accumulation of test hours, this process can also lengthen the product-development timeline. 

 

In contrast, lab-based durability testing can be performed on individual components and can accelerate the development timeline by subjecting the test sample to only the worst-case load scenarios. Component testing reduces costs, as a full-scale machine is not required. It also allows for a much more agile testing approach as numerous design iterations can be investigated prior to incorporating the component into the full-scale design. 

 

To suit different client needs, WESTEST offers various lab-based structural durability and fatigue test options, such as

 

     

  • force input testing, using hydraulic actuators to apply loads
  •  

  • vibration durability testing with specialized vibration tables, and/or
  •  

  • the use of a customized durability test rig to simulate a unique loading application.        
  •  

 

In all situations, it is important to understand the product duty cycle so that it can be accurately reproduced in the lab.

 

 Force Input Structural Durability/Fatigue Testing

 

WESTEST uses a MTS FlexTest controller and an assortment of different servo-controlled hydraulic actuators for its force input testing. This type of testing is commonly performed on structural machine or vehicle components that will be subjected to dynamic loads during their service life. Typically, the test sample is held rigid in a fixture. While in the fixture, hydraulic actuators, equipped with load cells and displacement transducers, are coupled to the test sample to apply the loads at the correct location and orientation. The FlexTest controller is programmed to control the actuators by applying precise test loads at a controlled rate and sequence. The load cells and displacement transducers measure the real-time force and displacement signals and provide a constant feedback signal to the controller, ensuring precise test control is maintained through the duration of the test. WESTEST's FlexTest controller has the ability to independently control up to four different hydraulic actuators, which allows up to four different test loads to be simultaneously applied to the test sample. This controller provides a broad range of load control options from simple sinusoidal load inputs to complex Remote Parameter Control (RPC)  loads that replicate actual loads measured and recorded during on-road or in-field data acquisition events. More on our Force Simulation Test Equipment.

 

Vibration Durability/Fatigue Testing

 

Vibration durability testing is conducted on WESTEST's multi-axial simulation table (MAST) system, vertical vibration table, horizontal vibration table, or electrodynamic shaker table . This testing is commonly performed on machine or vehicle components that will experience vibration loads throughout their service life. The test sample is secured to the platform of the shaker table using a test fixture or mounting system representative of its end-use installation. The shaker table platform is excited to produce the desired vibration inputs at the test sample, and accelerometers are used to provide feedback signals to ensure precise test control. WESTEST's MAST system, vertical vibration table and horizontal vibration table are all hydraulically controlled and ideally suited for testing vehicle or machine components that will be subjected to vibrations in the lower frequency range (up to 100 Hz). The electrodynamic shaker table is better suited for testing components that will be subject to higher frequency vibrations (up to 3,000 Hz). All vibration test equipment can be programmed to produce a wide range of vibration inputs.  More on vibration testing.

 

Custom Durability Testing

 

WESTEST regularly performs customized durability testing for vehicle, machinery, and component manufacturers. With an understanding of the duty cycle, loads, and constraints, our team of engineers and technologists will work with you to develop a customized test solution to meet your requirements. Examples of customized durability tests previously conducted by WESTEST include gearbox and driveline testing, bump testing, wear testing, and general cyclic product functionality testing.

 

Benefits of Structural Durability and Fatigue Testing

 

     

  • Prevents over-design and saves on unnecessary materials costs.
  •  

  • Improved product reliability reflected in increased customer satisfaction and fewer warranty claims.
  •  

  • Requires less time than field testing and gets products to market faster.
  •  

  • Permits testing of isolated components to measure performance without machine interference.
  •  

  • Is independent of environmental factors and precisely repeatable allowing for direct comparison of competing designs.
  •  

  • Is an economical and convenient alternative to traditional methods.
  •  

  • Verifies computer modeling and simulation.
  •  

 

Test Equipment 

 

 

Click the link for details and specifications