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This work presents the development of a new approach to EMAT finite element method (FEM) simulations by using a novel coupled electromagnetic-mechanical equation system. Validation is performed within the limits of the un-coupled equations using commercially available FEM codes. The advantages and drawbacks of the new method versus the traditional un-coupled approach are evaluated for various EMAT patterns. Numerical FEM analyses use a sparse direct solver with either Euler or Crank-Nicolson implicit time integration methods.

Two-dimensional axis-symmetric finite element method (FEM) simulations are conducted to study remote field eddy current testing (RF-ECT) in ferromagnetic steam generator (SG) tubes for fast breeder reactors (FBR). The present work investigates a combination of quasi-static and transient analysis with both linear and non-linear material properties. Two FEM codes are employed: a commercial one based on COMSOL and a 2D-FEM code developed in-house. Both codes are used to evaluate the influence of the speed of the ECT probe during in-service inspection of SG tubes at a low excitation frequency. As a result, the maximum error in SG tube defect detection when using the classical linear and quasi-static approximations is obtained.

In this work the behavior of high temperature (400C) low-cycle fatigue crack propagation during in-plane bending of an elbow from Monju Liquid Metal Fast Breeder Reactor (LMFBR) is presented in three stages. First, experimental measurements made in a real-size laboratory specimen are presented. This test was carried out under displacement-controlled conditions, with artificial defects introduced in the crown parts, where the maximum stress arises. Second, the experimental setup is simulated making use of Finite Element Analysis (FEA), in order to obtain the actual stress distribution through the loaded elbow. Finally, based on the FEA data, deterministic fatigue crack propagation based on the J-integral criterion is compared with the experimental data. Overall a good agreement was observed between experimental and analysis results, highlighting our capacity to evaluate such phenomena without necessarily incurring into extensive experimental work. In the future these tools will keep supporting the cost-efficient acceleration and improvement of LMFBR design and inspection criteria.