A sheet of brittle material, such as glass, flat or bowed, is separated along a score line by applying vibration energy through a probe into previously scored sheet material. The separation time is less than 1 second with smooth edge quality. The brittle material can be in the form of a moving ribbon of glass sheet, where a vibrational load is applied transverse to the score line to enhance crack propagation along the score line. A controller operates the probe at selected vibration frequencies, amplitudes, contact velocities, contact forces of impact, alignment with the score line, and the like, depending on material properties and structure, and depending on optimal process parameters.