8112 KB29 KB199920252014Pejkowski, ŁukaszSempruch, JanuszSkibicki, Dariuszletnik:60številka:9str. 549-560, SI 102ISSN:0039-2480COBISSID:13698843URN:URN:NBN:SI:doc-8GA5G27BenZveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikfraktografijaneproporcionalna obremenitevvečosno utrujanjevisokociklično utrujanjezunaj fazeHigh-cycle fatigue behavior of austenitic steel and pure copper under uniaxial, proportional and non-proportional loading|Austenitic steel EN: X2CrNiMo17-12-2 (ASTM: 316L) and copper Cu-ETP (DIN: E-Cu58, EN: CW004A, ASTM: C11000) were subjected to tension-compression, torsion and complex loads, including non-proportional loads. The non-proportionality of the state of stress resulted from a phase shift of the value delta = 90° of load components with sine signals and variable ratio of shear to normal stress lambda. On the basis of the results, Wöhler's curves were prepared, presenting the dependency of fatigue life to equivalent stress levels. Their analysis shows that fatigue life is strictly connected with the value of coefficient lambda. The existence of its critical value can also be observed, which results in the highest fatigue life reduction. The value is different for each material. Furthermore, fractographic tests were conducted showing the influence of the level and type of load on the fracture faceČlanek analizira vpliv razmerja med strižnimi in normalnimi napetostmi v pogojih večosnih utrujenostnih obremenitev na utrujenostno trajnostno dobo, morfologijo površine utrujenostnega loma in orientacijo ravnine razpoke. Cilji so bili doseženi z dvoosnimi utrujenostnimi preskusi z bakrom Cu-ETP in avstenitnim jeklom X2CrNiMo17-12-2. Preskušanci so bili obremenjeni z aksialno silo in momentom na standardnem dvoosnem sistemu za preskušanje Instron, pri čemer so bile nadzorovane napetosti. Materiala sta bila izbrana zaradi razmeroma velike občutljivosti na neproporcionalne obremenitve, ki izhaja iz njune majhne vrednosti energije napake zlogaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo