METHOD FOR DETERMINATION OF PLASTIC AND ELASTIC COMPONENTS OF CONSTRUCTIONAL MATERIAL HYSTERESIS LOOP Russian patent published in 1998 - IPC

FIELD: examination and analysis of materials. SUBSTANCE: zero deformation characteristic of the first specimen-standard made of homogeneous material without internal stresses in measured in elastic area. Two specimens are manufactured from the same homogeneous material. First deformation characteristic of one of specimens is measured. Then condition of these two specimens is stabilized by annealing till internal plastic stresses are removed completely. This done, second deformation characteristic of the same specimen is measured, and value and sign of internal stresses for both specimens are determined. For plotting the hysteresis loop first and second deformation characteristics of second specimen are combined with zero characteristic of first specimen in one system of coordinates. Total width of plastic and elastic components of hysteresis loop is determined for second specimen by value and sign of internal stresses as well as by slope angle to axis of anscissa, with load removed, graphically or from expression. EFFECT: reduced measurement errors. 5 dwg, 1 tbl