The simulation of the variation in the ultrasonic wave characteristics during the steel sample building by wire arc additive manufacturing

The aim of the present paper is simulation of the ultrasonic wave propagation during sample building by additive manufacturing under ultrasonic assistance. The simulation was carried out using the explicit dynamics modulus of ANSYS. To find the mesh sizes for ANSYS simulation, the analytical solution of the wave equation was found using the dynamic Euler-Bernoulli beam equation. The mesh size was varied from 1 to 5 mm and the results were compared to Euler-Bernoulli solution. The best agreement between the solution and the simulation was found if mesh size was 2 mm. The ultrasonic wave propagation was simulated in the samples with a height varied from 6 to 60 mm. It was found that an increase in the sample height decreased the wave amplitude. If the sample height was larger than 30 mm, then the wave amplitude was different at various levels from the substrate. This occurred since the variation in geometric sizes and mass of the sample affected the planar second moment of area, cross-sectional area and boundary conditions that influenced the wave amplitude and number. In the samples with a height of 30 mm or less, the ultrasonic wave amplitude did not depend on the y position but it was different for various z position that might affect the mechanical properties. To confirm this assumption, two steel samples were manufactured without and under the ultrasonic assistance and the microhardness was measured in various cross-sections. It was found that the microhardness was the same in cross sections of the sample manufactured without ultrasonic assistance, and it was different in the sample produced under the ultrasonic assistance.

1. St.Petersburg Science Foundation - № 23-RB-09-43
2. the Belarus Republican Foundation for Fundamental Research - Т24СПбГ-008