Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Cares/life Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program ... Nasa/tm--2003-106316 ... National Aeronautic
Author: CARES/LIFE Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program
Author: Noel N. NemethPredicting the Reliability of Ceramics Under Transient Loads and Temperatures with Cares/Life
Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781720664659
Category :
Languages : en
Pages : 28
Book Description
A methodology is shown for predicting the time-dependent reliability of ceramic components against catastrophic rupture when subjected to transient thermomechanical loads (including cyclic loads). The methodology takes into account the changes in material response that can occur with temperature or time (i.e., changing fatigue and Weibull parameters with temperature or time). This capability has been added to the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code. The code has been modified to have the ability to interface with commercially available finite element analysis (FEA) codes executed for transient load histories. Examples are provided to demonstrate the features of the methodology as implemented in the CARES/Life program.Nemeth, Noel N. and Jadaan, Osama M. and Palfi, Tamas and Baker, Eric H.Glenn Research CenterMECHANICAL PROPERTIES; CERAMICS; TIME DEPENDENCE; TRANSIENT LOADS; STRUCTURAL ANALYSIS; CRACK PROPAGATION; FINITE ELEMENT METHOD; STRESS INTENSITY FACTORS
Ceramics Analysis and Reliability Evaluation of Structures (Cares). Users and Programmers Manual
Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781723538209
Category :
Languages : en
Pages : 234
Book Description
This manual describes how to use the Ceramics Analysis and Reliability Evaluation of Structures (CARES) computer program. The primary function of the code is to calculate the fast fracture reliability or failure probability of macroscopically isotropic ceramic components. These components may be subjected to complex thermomechanical loadings, such as those found in heat engine applications. The program uses results from MSC/NASTRAN or ANSYS finite element analysis programs to evaluate component reliability due to inherent surface and/or volume type flaws. CARES utilizes the Batdorf model and the two-parameter Weibull cumulative distribution function to describe the effect of multiaxial stress states on material strength. The principle of independent action (PIA) and the Weibull normal stress averaging models are also included. Weibull material strength parameters, the Batdorf crack density coefficient, and other related statistical quantities are estimated from four-point bend bar or unifrom uniaxial tensile specimen fracture strength data. Parameter estimation can be performed for single or multiple failure modes by using the least-square analysis or the maximum likelihood method. Kolmogorov-Smirnov and Anderson-Darling goodness-of-fit tests, ninety percent confidence intervals on the Weibull parameters, and Kanofsky-Srinivasan ninety percent confidence band values are also provided. The probabilistic fast-fracture theories used in CARES, along with the input and output for CARES, are described. Example problems to demonstrate various feature of the program are also included. This manual describes the MSC/NASTRAN version of the CARES program. Nemeth, Noel N. and Manderscheid, Jane M. and Gyekenyesi, John P. Glenn Research Center NASA-TP-2916, E-4722-1, NAS 1.60:2916 RTOP 505-63-1B...
Nasa/Cares Dual-Use Ceramic Technology Spinoff Applications
Author: National Aeronautics and Space Adm NasaPublisher: Independently Published
ISBN: 9781792698170
Category : Science
Languages : en
Pages : 26
Book Description
NASA has developed software that enables American industry to establish the reliability and life of ceramic structures in a wide variety of 21st Century applications. Designing ceramic components to survive at higher temperatures than the capability of most metals and in severe loading environments involves the disciplines of statistics and fracture mechanics. Successful application of advanced ceramics material properties and the use of a probabilistic brittle material design methodology. The NASA program, known as CARES (Ceramics Analysis and Reliability Evaluation of Structures), is a comprehensive general purpose design tool that predicts the probability of failure of a ceramic component as a function of its time in service. The latest version of this software, CARESALIFE, is coupled to several commercially available finite element analysis programs (ANSYS, MSC/NASTRAN, ABAQUS, COSMOS/N4, MARC), resulting in an advanced integrated design tool which is adapted to the computing environment of the user. The NASA-developed CARES software has been successfully used by industrial, government, and academic organizations to design and optimize ceramic components for many demanding applications. Industrial sectors impacted by this program include aerospace, automotive, electronic, medical, and energy applications. Dual-use applications include engine components, graphite and ceramic high temperature valves, TV picture tubes, ceramic bearings, electronic chips, glass building panels, infrared windows, radiant heater tubes, heat exchangers, and artificial hips, knee caps, and teeth. Powers, Lynn M. and Janosik, Lesley A. and Gyekenyesi, John P. and Nemeth, Noel N. Glenn Research Center NASA-TM-111694, NAS 1.15:111694, E-9550 ...
Ceramic Material Life Prediction: A Program to Translate Ansys Results to Cares/Life Reliability Analysis
Author: National Aeronautics and Space Adm NasaPublisher: Independently Published
ISBN: 9781729190722
Category : Science
Languages : en
Pages : 32
Book Description
This manual describes the use of the ANSCARES program to prepare a neutral file of FEM stress results taken from ANSYS Release 5.0, in the format needed by CARES/LIFE ceramics reliability program. It is intended for use by experienced users of ANSYS and CARES. Knowledge of compiling and linking FORTRAN programs is also required. Maximum use is made of existing routines (from other CARES interface programs and ANSYS routines) to extract the finite element results and prepare the neutral file for input to the reliability analysis. FORTRAN and machine language routines as described are used to read the ANSYS results file. Sub-element stresses are computed and written to a neutral file using FORTRAN subroutines which are nearly identical to those used in the NASCARES (MSC/NASTRAN to CARES) interface. Vonhermann, Pieter and Pintz, Adam Unspecified Center NAG3-879
Ceramics Analysis and Reliability Evaluation of Structures (CARES)
Author: Noel N. NemethPublisher:
ISBN:
Category : Ceramic materials
Languages : en
Pages : 236
Book Description
Failure Analysis of Ceramic Components
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Ceramics are being considered for a wide range of structural applications due to their low density and their ability to retain strength at high temperatures. The inherent brittleness of monolithic ceramics requires a departure from the deterministic design philosophy utilized to analyze metallic structural components. The design program ''Ceramic Analysis and Reliability Evaluation of Structures Life'' (CARES/LIFE) developed by NASA Lewis Research Center uses a probabilistic approach to predict the reliability of monolithic components under operational loading. The objective of this study was to develop an understanding of the theories used by CARES/LIFE to predict the reliability of ceramic components and to assess the ability of CARES/LIFE to accurately predict the fast fracture behavior of monolithic ceramic components. A finite element analysis was performed to determine the temperature and stress distribution of a silicon carbide O-ring under diametral compression. The results of the finite element analysis were supplied as input into CARES/LIFE to determine the fast fracture reliability of the O-ring. Statistical material strength parameters were calculated from four-point flexure bar test data. The predicted reliability showed excellent correlation with O-ring compression test data indicating that the CARES/LIFE program can be used to predict the reliability of ceramic components subjected to complicated stress states using material properties determined from simple uniaxial tensile tests.
Time-Dependent Reliability Analysis of Monolithic Ceramic Components Using the Cares/Life Integrated Design Program
Author: JP. GyekenyesiPublisher:
ISBN:
Category : Batdorf
Languages : en
Pages : 19
Book Description
The computer program CARES/LIFE calculates the time-dependent reliability of monolithic ceramic components subjected to thennomechanical and/or proof test loading. This program is an extension of the CARES (Ceramics Analysis and Reliability Evaluation of Structures) computer program. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing either the power or Paris law relations. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled using either the principle of independent action (PIA), Weibull's normal stress averaging method (NSA), or Batdorf's theory. Inert strength and fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. Two example problems demonstrating component reliability analysis and fatigue parameter estimation are included.
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