Experimental analysis of shear strength and strain rate on H2/CH4 pinch-off flames

•The strain rate and shear strength correlation is analyzed for pinch-off flames.•Pinch-off mapping analysis is performed at various fuel and air velocities.•When acoustic excitation is dominant, the strain rate increases.•When the shear effect is dominant, the shear strength increases.•Shear strength is suggested as a possible parameter for distinguishing pinch-off.