scholarly journals Damage initiation and evolution in Al-Si layered microstructures under shock loading conditions at atomic scales

2020 ◽  
Author(s):  
Marco J. Echeverria ◽  
Sumit Suresh ◽  
Avinash Dongare
2001 ◽  
Author(s):  
Xiaodong Tang ◽  
John D. Whitcomb

Abstract The damage initiation and evolution mechanisms in plain and satin weave composites were studied using three-dimensional finite element analysis. The tow paths of the weave were selected such that the wavy region of the tows were identical in both weaves. The damage initiation and evolution behaviors in these comparable wavy regions were compared and discussed in terms of stress components that initiate damage, the overall stress/strain relationship and the accumulation of the damaged volume in the warp tow, fill tow and matrix pockets. The results showed significant similarities in many aspects of the damage behaviors such as damage modes, stiffness loss and damage accumulation processes.


2019 ◽  
Vol 287 ◽  
pp. 02002
Author(s):  
Marina Franulovic ◽  
Kristina Markovic ◽  
Zdravko Herceg

Gears are mechanical components which experience high dynamic loading during their exploitation period. Therefore, their load carrying capacity together with life expectancy are often the main research interest in various studies. The research presented in this paper is focused on the materials response in spur gears tooth root, with the attention given to the repeated overloads during gears operation. In order to simulate low cycle fatigue by using numerical modeling of stress - strain relationship within material, the material model which takes into account isotropic and kinematic hardening is used here. Material response of specimens produced out of steel 42CrMo4 in different loading conditions is used for the calibration of material model, which is then applied to simulate damage initiation and materials stress - strain response in gears tooth root. The results show that materials response to the given loading conditions non-linearly change through the loading cycles.


2016 ◽  
Vol 119 (10) ◽  
pp. 109901
Author(s):  
C. A. Bronkhorst ◽  
G. T. Gray ◽  
F. L. Addessio ◽  
V. Livescu ◽  
N. K. Bourne ◽  
...  

1980 ◽  
Vol 16 (4) ◽  
pp. 462-466
Author(s):  
E. Z. Novitskii ◽  
V. D. Sadunov ◽  
T. V. Trishchenko

Author(s):  
G.T. Gray

Under shock-loading, twinning is observed in metals that do not twin under conventional loading conditions, for example copper and nickel where the stacking fault energy is about 78 and 128 ergs/cm2, respectively. Contradictions in the published data on the twinning stress in copper (from 1.6 GPa in thin films to 14.5-20 GPa in bulk specimens suggest differences associated with experimental techniques. This study examines the role of residual plastic strain (eres) on the deformation substructures, particularly twinning, in shock-roaded copper.


2012 ◽  
Vol 26 ◽  
pp. 02008 ◽  
Author(s):  
J.P. Escobedo ◽  
E.K. Cerreta ◽  
D. Dennis-Koller ◽  
B.M. Patterson ◽  
R.A. Lebensohn ◽  
...  

Author(s):  
Mark A. Rhoads ◽  
Manohar Bashyam ◽  
William J. Crecelius

General Electric Aircraft Engines under contract from the Advanced Research Projects Agency (ARPA), has demonstrated the ability of ceramic rolling elements to withstand shock loading conditions experienced during race spalling, has performed a series of full scale tests directed at showing the thermal benefit of large hybrid bearings at speeds up to 3.0 MDN, and has developed a condition monitoring device that detects both ceramic and metallic bearing debris. The details of the three primary tasks are presented in this paper: Task 1 involves the testing of a hybrid bearing operating in severe shock loading conditions, with comparisons to an all steel bearing. Task 2 involves back-to-back comparison of an all-steel high speed bearing to a hybrid bearing of the same geometry and to a hybrid bearing of tighter race curvatures, showing differences between outer ring temperatures of all-steel and hybrid bearings. Task 3 deals with the bench testing of a new ultrasonic bearing condition monitoring device, designed to collect and detect both ceramic or metallic debris.


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