Electromagnetic Simulation Of Eddy Current Sensor

Eddy Current Sensor(ECS) is an nondestructive testing component,which is applied extensively in engineering and science researches.However, the testing performances are sensitive to the material properties (such as resistivity ρand relative permeability μr), which hampers eddy current sensor applied more conveniently and extensively. So, it is necessary and important to study on the electromagnetic properties of ECS. Finite Element Method and Experiments are adopted in this thesis to study the electromagnetic properties of ECS. The research work conducted is outlined as following. 1. Theory studies on the electromagnetic properties of ECS Based on foundational principals and equivalent circuit of ECS, effects that the relative parameters (such as testing distance, frequency etc.) to the properties of ECS are addressed. 2. Study on the electromagnetic modeling of ECS Based on the modeling theory of FEM and the electromagnetic foundational theory, the finite element model is built by simplifying appropriately the original model, selecting the element type, meshing and defining the boundary conditions. Then, the model is solved, and the result from analysis is compared with that from the works home and aboard, which strengthens the validity of the model. 3. Finite element analysis of the electromagnetic properties of ECS The effect of the tested material parameters, testing distance, coil shape and frequency to the properties of ECS are addressed in detail and respectively in the thesis. The rule of the electromagnetic field of ECS and eddy field of tested are studied under every factors. 4. Study on the relativity of tested material and ECS At present, ECS obtains the relationship of the output voltage and the testing distance by controlling the equivalent impedance. In the thesis, the relativity of tested material and ECS is studied by controlling the real part and the image part of the impedance of the coil. The innovations of the thesis mainly include following aspects: 1. The effects of the testing distance and frequency to the properties of ECS are reasoned out.