MAGNETIC MONITORING OF THE STRESS-STRAIN STATE AND RESIDUAL SAFE LIFEOF THE STEEL STRUCTURES OF HOISTING CRANES

Measurements of coercivity are used to evaluate the stress-strain stat e and determine the residual safe life of the steel structures of carg o cranes. Results are presented from experimental studies that establi shed a linear relationship between coercivity H-c and strain epsilon ( for strains smaller than 10%). A examination is made of the effect of plastic deformation and cumulative fatigue damage on H-c. Practical re commendations are given on predicting the residual safe life on the ba sis of H-c.