A testing system for causing a physical change in a crack tip region of a crack within a specimen. The testing system includes a load application system for applying a load to the specimen having the crack formed therein, an electrothermal system for applying an electrical current through the specimen and comprising a power supply and a controller operably coupled to the load application system and the electrothermal system. The load application system configured to perform a crack growth test on the specimen. A method of thermally influencing a crack tip region of a crack within a specimen includes applying at least one pulse of current to the specimen to generate flux tangentially around the crack within the specimen and at the crack tip region and causing the crack tip region of the crack within the specimen to reach a predetermined activation temperature.