A surgical apparatus comprises a body, an ultrasonic transducer, a shaft, an acoustic waveguide, an articulation section, an end effector, and an articulation drive assembly. The ultrasonic transducer is operable to convert electrical power into ultrasonic vibrations. The shaft couples the end effector and the body together. The acoustic waveguide is coupled with the transducer. The articulation section includes a collar that is located distal to a nodal portion of the waveguide and is operable to deflect the end effector away from the longitudinal axis. The end effector comprises an ultrasonic blade in acoustic communication with the ultrasonic transducer. The articulation drive assembly is operable to drive articulation of the articulation section. The articulation drive assembly comprises at least one translating articulation driver coupled with the collar. The ultrasonic blade is operable to deliver ultrasonic vibrations to tissue even when the articulation section is in an articulated state.