Secondary impact preventing device of drop hammer impact testing machine and testing method of secondary impact preventing device

The invention relates to a secondary impact preventing device of a drop hammer impact testing machine and a testing method of the secondary impact preventing device, and belongs to the technical fieldof engineering experiment equipment. The secondary impact preventing device comprises a top plate, a base, supporting rods, guide rods and a sliding plate, wherein an electromagnetic capturing and lifting device is arranged under the top plate; an objective table is mounted on the base, and a cushion block is mounted on the objective table; supporting rods are fixed to the periphery of the base,guide rods are installed in the middles of the supporting rods, and the upper portions of the supporting rods and the guide rods are fixed to the top plate; the two ends of the sliding plate are installed on the guide rods, the balance weight chamber is installed under the sliding plate, a hammer base is installed under the balance weight chamber, and a drop hammer is installed under the hammer base; a fixing rod is installed in the center of the counterweight chamber; and an infrared emitter I, an infrared emitter II, an optical sensor I and an optical sensor II which are level with the top part of a sample are mounted at the lower ends of the four supporting rods respectively. By means of electromagnetic capture and lifting, the possibility of secondary impact is effectively reduced, operation is convenient, the structure is simple, and impact tests of different types of hammer heads can be conducted on samples of various test specifications.