Analysis On Crack Accident Of 1700 Hot Rolling Mill Roller-chop Shear Frame

Frame is a permanent part of flying shear, is one of the most important components of it, which is used to install the flying shear body, bear the shock and the tipping force when it works. Its strength and deformation will affect the overall equipment reliability and efficiency units, so the frame should have adequate strength and long service life, to ensure continuous production. Therefore, to master frame flying shear stress and strain, and on this basis, analyzing its fatigue life play a very important instructional role on maintenance of the frame, service life and design standards.In light of chop-shear frame breakage of a 1700 hot-rolled line, the thesis analyzed stress and deformation of the frame with the finite element method and compared them with field test results. Then obtained the dangerous parts of the stress spectrogram by the on-spot test, and predicted service life of the frame with modified Miner rules and Corten-Dolan linear damage theory. Finally on this basis, put forward some improved measures and programs that can increase strength and life of the frame and evaluate the program. The main contents are following:1) According to the flying shear parameters and calculated the actual load condition of the bearing block, combined installation mode of the bearing block and the frame, calculate the load received by the frame. Analyzed strain and stress on the frame with finite element software;2) Took a field test to the necessary area with electrical measurement method. Compared the test result with finite element simulation results, it turns out that both the results are unanimous;3) Obtained the dangerous part of the stress spectrogram based on the on-spot test data. Estimated both the fatigue life of the most dangerous part of the frame with Modified Miner Rules and Corten-Dolan fatigue life predicted methods, it shows that the results of two estimated methods is fairly close;4) In light of the actual destruction situation and the finite element simulation results, made a improved program for the frame. Then evaluated the program, it turns out that the improved program can effectively increase the fatigue life of the frame.