In most modern aircraft /recently certificated designs, the autopilot should disconnect if the pilot applies an overpowering force.
In other aircraft, depending on system design, the overpowering force could be interpreted by the autotrim as being out of trim, thus it will attempt to trim the aircraft away from the datum condition with potentially hazardous outcome. There is a history of such accidents and incidents relating to loss of control.
Do not overpower automatic systems, disengage and fly the aircraft manually; and similarly ensure that the aircraft is in trim before engaging the autopilot.