Integrated Computational Durability Analysis

1993 ◽  
Vol 115 (4) ◽  
pp. 492-499 ◽  
Author(s):  
W. K. Baek ◽  
R. I. Stephens ◽  
B. Dopker
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Life Prediction ◽  
Dynamic Stress ◽  
Local Strain ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Finite Element Stress Analysis ◽  
Multibody Dynamic ◽  
Crack Initiation Life

A computer aided analysis method is described for durability assessment in the early design stages using multibody dynamic analysis, finite element stress analysis, and fatigue life prediction methods. From multibody dynamic analysis of a mechanical system, dynamic loads of a mechanical component were calculated. Finite element stress analysis with substructuring techniques produced accurate stress fields for the component. From the dynamic loads and the stress field of the component, a dynamic stress history at the critical location was produced using the superposition principle. Using Neuber’s rule, a local strain time history was produced from the dynamic stress history. The local strain based fatigue life prediction method was then used to predict “crack initiation” life of the critical component. The predicted fatigue crack initiation life was verified by experimental durability tests. This methodology can be combined with identification of weak links and optimization techniques such that the design optimization for an entire mechanical system based upon durability is possible during the early product development stage.

Fatigue Life Predictions by Coupling Finite Element and Multibody Systems Calculations

1997 ◽  
Author(s):  
Stefan Dietz ◽  
Helmuth Netter ◽  
Delf Sachau
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Elastic Body ◽  
Multibody Systems ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Multibody Simulation ◽  
Bogie Frame ◽  
Life Predictions

Abstract The dynamic loads and accelerations acting on a railway bogie are predicted by multibody simulation. The bogie frame is considered as an elastic body of the MBS-model, in which elastic displacements are represented by eigen and staticmodes. Stresses are calculated for the most stressed locations of a bogie in the MBS-postprocessor. Based on these a fatigue life prediction is carried out.

Dynamic Stress Analysis Method and Its Application for Urethane Wheels Using the Computer Model

2006 ◽  
Vol 321-323 ◽  
pp. 1601-1604
Author(s):  
Kab Jin Jun ◽  
Ji Won Yoon ◽  
Tae Won Park ◽  
Joong Kyung Park
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Dynamic Stress ◽  
Fatigue Life Prediction ◽  
Design Stage ◽  
Analysis Method ◽  
Early Design Stage ◽  
Multibody Dynamic ◽  
Dynamic Stress Analysis ◽  
Damage Rule

An Over Head Transportation (OHT) vehicle is used to transport large loads in a factory more efficiently. To maximize productivity, the speed and load requirement for the OHT vehicle is continually increasing. This may create a repetitive dynamic load and thus cause fatigue failure in related components. In this paper, a computer aided engineering (CAE) method is proposed for fatigue life prediction in the early design stage using multibody dynamic analysis and the linear damage rule. The process of predicting the fatigue life using the proposed computer models in this paper may be applied to structures of various mechanical systems.

TTK Chitra tilting disc heart valve model TC2: An assessment of fatigue life and durability

2017 ◽  
Vol 231 (8) ◽  
pp. 758-765 ◽  
Author(s):  
NN Subhash ◽  
Adathala Rajeev ◽  
Sreedharan Sujesh ◽  
CV Muraleedharan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Heart Valve ◽  
Life Prediction ◽  
Heart Valves ◽  
Failure Modes ◽  
Fatigue Life Prediction ◽  
Element Analysis ◽  
Valve Model

Average age group of heart valve replacement in India and most of the Third World countries is below 30 years. Hence, the valve for such patients need to be designed to have a service life of 50 years or more which corresponds to 2000 million cycles of operation. The purpose of this study was to assess the structural performance of the TTK Chitra tilting disc heart valve model TC2 and thereby address its durability. The TC2 model tilting disc heart valves were assessed to evaluate the risks connected with potential structural failure modes. To be more specific, the studies covered the finite element analysis–based fatigue life prediction and accelerated durability testing of the tilting disc heart valves for nine different valve sizes. First, finite element analysis–based fatigue life prediction showed that all nine valve sizes were in the infinite life region. Second, accelerated durability test showed that all nine valve sizes remained functional for 400 million cycles under experimental conditions. The study ensures the continued function of TC2 model tilting disc heart valves over duration in excess of 50 years. The results imply that the TC2 model valve designs are structurally safe, reliable and durable.

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