The creep fatigue testing machine is a key equipment for evaluating the durability of materials under the combined effects of high temperature, high stress, and cyclic loading. Its simulation process is achieved by precisely controlling three core parameters.

1. Accurate environmental simulation:

The core of the testing machine is a high-temperature furnace or environmental chamber, which can heat the sample and stabilize it at the target temperature for a long time (up to 1200 ° C or above). This temperature is usually close to 0.3 to 0.7 times the melting point of the material, and is the region where creep effects are significant. The precise temperature control system ensures that the temperature gradient within the specimen gauge is extremely small throughout the entire testing process, avoiding the generation of additional thermal stress and accurately simulating the actual working thermal environment of components such as aircraft engine blades and turbine disks.

2. Complex load simulation:

The equipment applies high stress through a high stiffness servo mechanical or hydraulic actuation system. The core of its technology lies in the ability to independently or coupled control stress (load) and strain. The experiment usually adopts the "strain control" or "stress control" mode to simulate the load spectrum in reality:

Holding time: Introducing holding time at peak stress or strain is crucial for simulating creep. During this period, the material undergoes sustained creep deformation under constant high stress, resulting in microscopic damage such as pores and grain boundary slip.

Cyclic load: Simulate mechanical fatigue caused by equipment start stop and power changes through alternating tension compression or tension hold compression hold load waveforms, leading to fatigue crack initiation.

3. Data collection and lifespan prediction:

Throughout the entire experimental process, the system continuously collected high-frequency data on load, strain, temperature, and time, and plotted the stress-strain hysteresis loop. By analyzing the shape of the loop, creep strain rate, cyclic softening/hardening rate, and the number of cycles/time of final fracture, researchers can establish a constitutive model and damage evolution equation for the material. These data are the basis for constructing a creep fatigue interaction damage model, which can be used to predict the service life and reliability of actual engineering components under complex working conditions.

In summary, the device accurately reproduces the triple coupling environment of "temperature stress time", accelerates material damage, and thus reveals its failure mechanism and quantifies its lifespan in the laboratory.