Abstract
Low cycle fatigue (LCF) is a critical issue in the design and application of metallic structures subjected to cyclic loading. The use of additive manufacturing technology has enabled the construction of complex structures with unique mechanical properties, such as auxeticity. These components are reliant on plastic hinges operating at the macro and meso scales. Design of these components therefore requires careful consideration the plastic behavior of the underlying material under repeated loading. While LCF behavior has been well characterized for 316L stainless steel in the wrought condition, it has been shown that there are significant differences in the monotonic behavior of laser powder bed fusion (L-PBF) versus wrought, which have yet to be quantified under cyclic loading. An L-PBF process has been employed to generate representative material for LCF characterization. Testing of LPBF 316L under ambient conditions have been conducted with strain ranges of 0.2 and 0.4% and compared to normalized wrought equivalents tested under the same conditions. The evolution of initial to stabilized stress amplitudes will be described as well as the evolution of minimum and maximum stresses attained. The differences in elastic and plastic response will be described within the context of a kinematic hardening model for this material, with the aim to provide design parameters for auxetic components that can be realized for this novel processing route with this material. The findings are expected to inform the design and development of LCF-resistant structures using additively manufactured 316L stainless steel, particularly in high-performance applications where cyclic loading is a critical issue. Session
