Abstract: A simple prediction method for low-cycle fatigue life of structure under field load is described. Under rotating speed spectrum, the prediction for fatigue life of jet engine compressor disk is given. The predicting results are compared favorably with actual test results for the same material and under the same rotating speed spectrum. The key in this prediction is to obtain typical load(P) versus local damage(D) curve(P-D)at the critical load, existing material propertices and plasticelastic F.E.M. The fatigue life of structures can be determined with the P-d curve and field specturum by computer program. Therefore, the prediction can save time and money, and the results are satisfactory.

Key words: fatigue life, disk, plasticelastic FEM