Reflection of an impulsive torsional wave by a moving boundary

• Reflection problem of an impulsive torsional wave by a moving boundary is discussed exactly.
• A torsional wave source which produces the simple spherical wave is discussed.
• Exact closed form solution for the reflected wave is obtained.
• A new wave is found.
• Development of wave front shape is analytically obtained and illustrated.

Reflection of an impulsive torsional wave by a uniformly moving surface/boundary is discussed. Applying the Cagniard–de Hoop technique, the solution for the reflected wave is obtained in the closed form and a new wave that runs along the moving boundary has been found. Its wave front singularity is stronger than those of the incident and the regular reflected waves. This new wave has the cylindrical surface, but the shape of the disturbed region is a torus with a triangular-like cross section.