Use of Mechanistic Life Prediction Methods for the Design of Damage-Tolerant Composite Material Systems

2009 ◽  
pp. 3-3-16 ◽  
Author(s):  
KL Reifsnider
Keyword(s):  
Composite Material ◽  
Life Prediction ◽  
Prediction Methods ◽  
Material Systems ◽  
Damage Tolerant

Interface/Interphase Concepts in Composite Material Systems

1990 ◽  
Vol 3 (1) ◽  
pp. 13-23 ◽  
Author(s):  
R.E. Swain ◽  
K.L. Reifsnider ◽  
K. Jayaraman ◽  
M. El-Zein
Keyword(s):  
Composite Material ◽  
Material Systems

scholarly journals Damage Tolerance in Biomedical Implants: Cardiac Valves and Endovascular Stents

2000 ◽  
Author(s):  
R. O. Ritchie
Keyword(s):  
Life Prediction ◽  
Heart Valves ◽  
Damage Tolerance ◽  
Heat Rate ◽  
Pyrolytic Carbon ◽  
Endovascular Stents ◽  
Prosthetic Implants ◽  
Useful Life ◽  
Valve Prostheses ◽  
Damage Tolerant

Abstract The human heat rate is roughly 40 million beats per year. To prosthetic implants such as mechanical heart valves and endovascular stents, this means that they must endure almost 109 fatigue cycles during the patient’s lifetime. To prevent premature mechanical failures of such devices, which inevitably lead to patient fatalities, considerations of damage-tolerant design and life-prediction methodologies represent a preferred approach. In this presentation, a damage-tolerant approach to life prediction and “quality control” for both metallic and ceramic heart valve prostheses is presented, based on the notion that the useful life of the device is governed by the time for incipient defects in the material to propagate, by stress corrosion or more critically fatigue, to failure. Based on these analyses, the relative benefits of metallic (Co-Cr, Ti-6Al-4V) vs. ceramic (pyrolytic carbon) valves are discussed. Finally, analogous considerations are presented for endovascular stents, particularly those processed by laser cutting of the superelastic Ni-Ti alloy Nitinol. Again, the relative benefits of Nitinol vs. more traditional metallic implant materials (stainless steel, Co-Cr, titanium, titanium alloys) are discussed.

scholarly journals Design of experiments for verification of computational life prediction methods

2019 ◽  
Vol 18 (3) ◽  
pp. 143-154
Author(s):  
O. V. Samsonova ◽  
K. V. Fetisov ◽  
I. V. Karpman ◽  
I. V. Burtseva
Keyword(s):  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Turbine Engines ◽  
Prediction Methods ◽  
Gas Turbine Engines ◽  
Loading Conditions ◽  
Load History ◽  
Strain Behavior ◽  
Before And After ◽  
Two Stages

The failure of heavily loaded rotating parts of aviation gas turbine engines may bring about dangerous consequences. The life of such parts is limited with the use of computational and experimental methods. Computational life prediction methods that are used without carrying out life-cycle tests of engine parts or assemblies should be substantiated experimentally. The best option for verifying the computational methods is to use the results of cyclic tests of model disks. These tests make it possible to reproduce loading conditions and surface conditions that correspond to those of real disks, and the data on the load history and material properties make it possible to simulate stress-strain behavior of disks under test conditions by calculation. This paper shows the process of planning such tests. It is assumed that the tests will be carried out in two stages - before and after the initiation of a low-cycle fatigue crack. A number of criteria are formulated that the geometry of model disks and their loading conditions are to satisfy. Based on these criteria, model disks were designed and the conditions for their testing were selected.

Validation of Inelastic Analysis by Full-Scale Component Testing

1987 ◽  
Vol 109 (1) ◽  
pp. 42-49 ◽  
Author(s):  
D. S. Griffin ◽  
A. K. Dhalla ◽  
W. S. Woodward
Keyword(s):  
Life Prediction ◽  
Elevated Temperatures ◽  
Full Scale ◽  
Prediction Methods ◽  
Material Models ◽  
Component Testing ◽  
Inelastic Analysis ◽  
Creep Buckling ◽  
Design Requirements ◽  
Thermal Striping

This paper compares theoretical and experimental results for full-scale, prototypical components tested at elevated-temperatures to provide validation for inelastic analysis methods, material models, and design limits. Results are discussed for piping elbow plastic and creep buckling, creep ratcheting, and creep relaxation; nozzle creep ratcheting and weld cracking; and thermal striping fatigue. Comparisons between theory and test confirm the adequacy of components to meet design requirements, but identify specific areas where life prediction methods could be made more precise.

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