The research objective of this collaborative project is to investigate high cycle fatigue failure in representative engineering alloys (304 austenitic stainless steel, Inconel 718+ Ni-based superalloy and Ti-6Al-4V alloy) with a tightly integrated modeling/experimental approach. A computational framework will be established based on the integration of an enriched space-time finite element method and a multiscale fatigue damage model. With this approach, new knowledge will be gained through studies on key factors such as load cycles, stress history and triaxiality, nonlinear coupling among the loads, and complex geometry, which are known to critically influence the fatigue failure and generally not fully accounted for in the empirical design approaches that are being practiced today. The fundamental mechanisms revealed through the computational efforts will be verified and validated through existing experimental data as well as proposed high cycle fatigue tests featuring in-situ monitoring of fatigue crack initiation and propagation. Additionally, microstructural characterization will be performed to establish a map between the observed microstructural deformation mechanism and the proposed multiscale material model.
If successful, this project will shed new night on the fundamental mechanisms that govern the high cycle fatigue failure in many critical engineering applications. Examples include turbines used for energy and power applications, aerospace structural components, and high-performance electronics. The multiscale simulation models and experimental techniques developed from this project will also be of interest to other researchers who are studying high cycle fatigue mechanism for a broader range of materials and devices. The acquired research results on the topic of high cycle fatigue will be fully incorporated into the undergraduate/graduate curricula. With a cyber-enabled approach, the knowledge will be disseminated through a variety of channels towards a wide range of audiences, including graduates, undergraduates, K-12 and underrepresented groups.
