Fatigue failure prediction of press fitted parts subjected to a cyclic loading condition by finite element methods

2007 ◽  
Vol 30 (12) ◽  
pp. 1194-1202 ◽  
Author(s):  
W. J. KANG ◽  
A. K. KIM ◽  
G. H. KIM
Keyword(s):  
Finite Element ◽  
Cyclic Loading ◽  
Fatigue Failure ◽  
Finite Element Methods ◽  
Loading Condition ◽  
Failure Prediction ◽  
Cyclic Loading Condition

Flow Controllability of Hydrogen Diffusion Driven by Local Stress Field for Steel under Cyclic Loading Condition

2012 ◽  
Vol 326-328 ◽  
pp. 626-631 ◽  
Author(s):  
Toshihito Ohmi ◽  
A.Toshimitsu Yokobori Jr. ◽  
Kenichi Takei
Keyword(s):  
Finite Element ◽  
Cyclic Loading ◽  
Hydrogen Embrittlement ◽  
Loading Condition ◽  
Hydrogen Diffusion ◽  
Local Stress ◽  
Cyclic Loading Condition ◽  
Diffusion Analysis ◽  
Concentration Behavior ◽  
Local Stress Field

The hydrogen diffuses and accumulates at the stress concentration area like a crack tip and it causes hydrogen embrittlement. To clarify the mechanism of hydrogen embrittlement, it is important to obtain the hydrogen concentration behavior. However, experimental detection is not feasible due to the high diffusivity of hydrogen and numerical analyses have been preceded. In this paper, by using a finite element and finite difference coupled method at which the diffusion analysis is performed by FDM coupled with the stress analysis by FEM, the analyses of hydrogen diffusion were conducted under cyclic loading conditions.

Unresolved Issues With Regard to Creep and Creep Fatigue Life Prediction

2002 ◽  
Author(s):  
J. Oh ◽  
N. Katsube ◽  
F. W. Brust
Keyword(s):  
Cyclic Loading ◽  
Damage Evolution ◽  
Life Prediction ◽  
Loading Condition ◽  
Cyclic Strain ◽  
Rupture Process ◽  
Steady State Creep ◽  
Creep Failure ◽  
Cyclic Loading Condition ◽  
Creep Fatigue

This paper studies intergranular creep failure of high temperature service material under a stress-controlled unbalanced cyclic loading condition. The grain boundary rupture process was numerically analyzed using Tvergaard’s axisymetric model. The present numerical model incorporated the experimentally verified Murakami-Ohno cyclic strain hardening creep law and Norton’s creep law. The numerical results show that void growth accelerates under cyclic loading condition. Also, analysis shows that a steady state creep law is not sufficient to analyze damage evolution under cyclic loading conditions.

scholarly journals The influence of stress level on the ratcheting magnitude and progress rate in steel alloys under uniaxial loading conditions

2021 ◽  
Author(s):  
Prasanth Chandrasekar
Keyword(s):  
Cyclic Loading ◽  
Plastic Strain ◽  
Strain Rate ◽  
Loading Condition ◽  
Stress Amplitude ◽  
Fatigue Loading ◽  
Mean Stress ◽  
Cyclic Loading Condition ◽  
Ratcheting Strain ◽  
Cyclic Damage

Engineering materials in their service life undergo symmetric or asymmetric fatigue loading, which leads to fatigue damage in the material. Ratcheting damage is due to the application of mean stress under cyclic loading condition. From deformation behavior perspective, application of mean stress under stress-controlled fatigue loading gives rise to accumulation of plastic strain in the material. Ratcheting strain increases with an increase in applied mean stress and stress amplitude. In addition, ratcheting behavior will increase in cyclic damage with the rise in strain accumulation and it can be illustrated by a shift in the hysteresis loop towards large plastic strain amplitudes. This study focuses on the ratcheting behavior of different steel materials under uniaxial cyclic loading condition and suggests a suitable method to arrest ratcheting by loading the materials at zero ratcheting strain rate condition with specified mean stress and stress amplitudes. The three dimensional surface is created with stress amplitude, mean stress and ratcheting strain rate for different steel materials. This represents a graphical surface zone to study the ratcheting strain rates for various mean stress and stress amplitude combinations.

scholarly journals Low Cycle Fatigue Failure of a Sitka Spruce Tree in Hurricane Winds

2014 ◽  
Vol 40 (5) ◽  
Author(s):  
Warren Leigh
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Wind Speed ◽  
Fatigue Failure ◽  
Low Cycle Fatigue ◽  
Failure Prediction ◽  
Picea Sitchensis ◽  
Cycle Fatigue ◽  
Hurricane Wind ◽  
The Impact

Pine plantations are prone to stem breakage due to high cyclic stress levels associated with hurricane force winds. Stress analytical and finite element simulation models were constructed of a representative profile of a (Sitka) Picea sitchensis tree. The profile surface stress (S) was determined due to the combined load of tree self-weight and hurricane wind speed. The results were complemented by reference to two other studies by other researchers that investigated the impact of fatigue cycles on failure (N) of pine wood and tree sway cycles to present a stem fatigue life prediction. The position of maximum surface profile stress and trunk fracture initiation location was ascertained from a non-uniform stress response. No stress uniformity along the trunk profile was observed for any wind-load case examined. The analytical model and finite element analysis of the P. sitchensis tree trunk profile revealed a statically adequate strength reserve factor of 1.4, which suggested another mode of failure was responsible. Fatigue life failure prediction was examined under cyclic and same-stress amplitude related to the hurricane wind speed of 33 m s-1. Predicted trunk fracture occurred in 2.6 hours, which dramatically reduced to two minutes with an increase in wind speed of only 1 m s-1. The calculated exposure time was similar to that recorded during Hurricane Hugo’s transit in 1989. The time-to-failure prediction obtained by the method of analysis provided in this study seemed plausible, and that the profile associated with the P. sitchensis tree would suffer trunk breakage by low cycle fatigue failure.

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