Crack-propagation test method and device

The patent relates to a crack-propagation test method and a device. The method comprises the steps of: firstly, prefabricating a test piece with a continuously-variable cross section area, then presetting cracks at different cross sections on the test piece, applying cyclic load on the test piece, simultaneously measuring the load size at the cracks, setting the cyclic step length of each time of experiment, and measuring the lengths of the cracks on the surface of the test piece after each cyclic step length is measured. The invention studies the influences of the initial lengths and the initial positions of the cracks, the load size, the loading mode and the ratio between the vibrating frequency and the stress on the crack-propagation characteristic of the test piece by adjusting the initial lengths and the initial positions of the cracks, the weight size, the loading mode, the exciting frequency and the exciting force. The invention has the advantages that the method is simple, the operation is convenient, the adaptability is strong, the accuracy is high, the energy consumption is less, the efficiency of the crack-propagation test can be effectively improved and the test cost is reduced.