Stulpinaitė A. Parameters of low cycle fatigue curves according to elastic and plastic strain: Master thesis of mechanical engineer / research advisor associate professor dr. R. Šniuolis; Šiauliai University, Technological Faculty, Mechanical Engineering Department. – Šiauliai, 2004. -60p. Parameters of fracture (parameters of low cycle fatigue curves m, C) are determined at homogeneous stress state and symmetric or asymmetric low cycle straining. Low cycle loading in structures appear near stress concentrators, cracks in little volumes of material which is limited of elastic strained zones. The elastic plastic loading may be in the welded joints, too. In the condition of variable loading the elastic strained metal impedes the accumulation of strain in these areas. Therefore the conditions of straining in these areas are similar to low cycle straining. At low cycle loading lifetime depends on reduction of areay. Coffin’s equation for calculation of constant C is not suitable for most materials and more complex equations must be used. Parameter C markedly differs from the experimental, therefore high errors occur in evaluating lifetime of the material. It is noticed in many works that parameter proposed by Coffin is close to experimental. Parameter m = 0,5, proposed by Coffin, is determined according the low cycle fatigue curves in coordinates . In some works the total strain e is used instead of plastic strain d . The difference of values of parameter m in this case is... [to full text]