Abstract:

The coupling of current, temperature and stress has been proposed in crack arresting by the electromagnetic heat effect at the moment when a pulse current is switched on. A simulation experiment has been conducted using a super density pulse current generator (model ZL 1) developed by the authors. Complex function analysis is applied in the theoretical analysis; the temperature and stress at the crack tip are solved in analytical solution after crack arresting. The numerical analysis process was finished by two ways of the thermal electrical coupled and thermal mechanical coupled. The results of the numerical simulation are in good agreement with the results of theoretical analysis and experiment. Theoretical analysis, experiment surveys and numerical calculations show that the tip of crack may be melted and the crater can be formed by metal melting when the crack is arrested by part crossover using the electromagnetic heat effect, which decreases the stress concentration and forms a compressive stress area. Therefore, the goal of crack preventing can be reached. This method can be applied in the fatigue crack prevention of the aerofoil root.

Key words: aluminum alloy plate, crack arresting, temperature field, thermal stress field