This paper presents a low cycle fatigue (LCF) failure analysis on [001], [011], and [111] orientations of a Ni‐based single crystal superalloys at 850 °C. Fracture mechanism and microstructure damage evolution are revealed through crystal plastic theory and fracture morphology analysis. Strain‐controlled LCF tests are conducted with the standard round bar samples; the fracture morphology and microstructure characteristics, such as the fracture mechanism and microstructure damage evolution, are observed via scanning electron microscopy (SEM), optical microscopy (OM). Crystal plastic theory is adopted to establish the crystal slip system framework, considering elastic and plastic strain rate, elastic orientation factors, and the resolved shear stress (Rss). The life prediction model is established based on Levkovitch damage theory, theoretical analysis, and test results has good consistency. The results demonstrate that fatigue life on [001] orientation is the longest, but considering the effects of stress amplitude and Young's modulus, [011] orientation exhibits the best fatigue performance. Under LCF loading, the initial crack starts to occur on surface of specimen if the internal defects are small and negligible; in contrast the initial crack starts to occur in subsurface or internal of specimen if the microstructure defects exist in material. The LCF cross‐section of SC belongs to the quasi‐cleavable type, the crack propagates in the direction of {111} plane and then extends along the vertical stress axis until the specimen fractures.
Numerical method was widely used in bridge seismic performance analysis, but the diversity and complexity structures increased trouble in the modelling process. This paper presented a systematic, universal and flexible bridge numerical modelling method, and the seismic performance of a concrete filled steel tubes arch bridge was studied. The geometric/attribute model involved structural/stiffness equivalence, and the bridge parametric modeling strategy combined commercial computer-aided design language of software MATLAB and ANSYS. Data exchange in different fields and rapid reconstruction of numerical model were realized. Finally, the vibration mode, deformation and internal force of the bridge under seismic load was studied. The results indicated that the proposed parametric model formed a complete data transfer process, and the bridge model rapidly modified and reconstructed. The numerical calculation efficiency was greatly improved because of the structure element was employed instead of solid element. The displacement and internal force of arch rib were mainly controlled by lateral load under horizontal uni-input, and the combined horizontal and vertical load should be considered in seismic design. The leaning angle and width-span ratio of transverse braces are considered to improve the seismic performance of bridges.
Numerical method is widely used in bridge seismic performance analysis, but the diversity and complexity structures increase trouble in the modeling process. This article presents a systematic, universal, and flexible bridge numerical modeling method, and the seismic performance of a concrete filled steel tubes arch bridge is studied. The geometric/attribute model involves structural/stiffness equivalence, and the bridge parametric modeling strategy combined commercial computer‐aided design language of software MATLAB and ANSYS. Data exchange in different fields and rapid reconstruction of numerical model are realizing. Finally, the vibration mode, deformation and internal force of the bridge under seismic load are studied. The results indicating that the proposed parametric model formed a complete data transfer process, and the bridge model can be rapidly modifying and reconstructing. The numerical calculation efficiency is greatly improved because of the structure element is employed instead of solid element. The displacement and internal force of arch rib are mainly controlling by lateral load under horizontal uni‐input, and the combined horizontal and vertical load should be considering in seismic design. The leaning angle and width‐span ratio of transverse braces are considered to improve the seismic performance of bridges.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.