R. Craig McClungSouthwest Research Institute®

An Executive Update on theTurbine Rotor Material Design (TRMD)

Program

6th Annual FAA/Air Force/NASA/Navy Workshop on the Application of Probabilistic Methods to Gas Turbine Engines

March 18-20, 2003

Outline

Industry background and perspectiveIntroduction to the TRMD programOverview of major tasks

Recent accomplishmentsFuture work

Introduction to DARWIN™ presentations

Background

Hard Alpha anomalies in titanium engine disks

Very rareCan cause failureNot addressed by safe life methods

Enhanced life management process

Requested by FAADeveloped by engine industryProbabilistic damage toleranceSupplements safe life approach

R. Craig McClungSouthwest Research Institute®

Aerospace Industries Association

Rotor Integrity Sub-Committee

A Summary for 2003 Probabilistic Workshop

March 18, 2003

Post Sioux City - Industry moves to incorporate Damage Tolerance

Safe Life Estimate

RISC developed an industry-wide framework for Damage Tolerance … and added this element to the

existing Life Management Process

AIA Rotor Integrity Sub-CommitteeCharter

• Address Industry Policy on Rotor Safety

• Assist FAA in implementing Ti Report

• Ti first, other materials later

GE Aircraft EnginesHamilton SundstrandHoneywellMTUPratt & Whitney

Pratt & Whitney CanadaRolls RoyceRolls Royce AllisonSNECMAFAA

Enhanced Life Management

Process

Analysis Methods &Matls Data

Damage

Tolerance

Devt. & Validation

Tests

New Element Added

Service Life & Product Assurance

Enhanced Life Management

Process

Materials

Safelife

Testing

AssuranceDT

RISC Vision - Comprehensive DT Assessment

Damage Tolerance Advisory Circular

Inherent Flaws(Melt related, etc)

Titanium Hard Alpha

Ni/Powder Metals

Analytical Method:

Probabilistic FMRisk Calc <DTR

Induced Flaws

Manufacturing Maintenance/ Service

•Retain Deterministic FM as fallback

Analytical Method:

Probabilistic FMRisk Calc <DTR

Current RISC Focus

•Analysis Tool calibrated by Test Case

•Criteria Calibrated by Experience

RISC ScheduleSioux City 7/19/89 Pensacola 7/6/96 AC33.14

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 20011989 1990 2002 2003

Draft Advisory Material to FAA 11/96

InherentAnomalies

InducedAnomalies

Ti

Ti

Ni

Ni

RISC Kickoff 10/91 Damage ToleranceFramework for all Future Work

FAA/SMPC Data GatheringOEM Data Gathering Started

Draft Advisory MaterialAvailable by 4Q2003

TRMD Goals

TRMD Program has two major goalsDevelopment of a practical software tool that implements the new probabilistic damage tolerance methodologyDevelopment of supplementary modeling and experimental characterization of material and anomaly behavior

Both goals support the implementation of FAA Advisory Circular 33.14

TRMD Team Leaders

Federal Aviation AdministrationBruce Fenton and Joe Wilson, Technical CenterTim Mouzakis, New England Regional Center

TRMD Subcontractors and Steering CommitteeDarryl Lehmann, Pratt & WhitneyJon Tschopp, General ElectricAhsan Jameel, HoneywellJon Dubke, Rolls-Royce Corp.

AIA Rotor Integrity Subcommittee (RISC)Southwest Research Institute

Gerry Leverant, original Program ManagerCraig McClung, current Program Manager

Major TRMD Phase II Contributors

General ElectricJon TschoppT. C. ChangShesh SrivatsaAndy WoodfieldGary MihlbachlerJon Bartos

HoneywellAhsan JameelYancy GillSandeep MujuMike Gorelik

Pratt & WhitneyDarryl LehmannMas Hongoh

Rolls-Royce Corp.Jon DubkeGeoff Ward

Southwest Research InstituteGerry LeverantCraig McClungMike EnrightLuc HuyseYi-Der LeeGraham ChellPete McKeighanKwai ChanPete LazChris Waldhart

Harry Millwater (UT-San Antonio)Simeon Fitch (Mustard Seed Software)

Major TRMD Tasks

Hard Alpha anomaly distribution updateValidation of forging deformation modelCrack nucleation/growth data and modelingDARWIN™ software development/validationTechnology transfer

Example HA Distributions

Post 1995 Triple Melt/Cold Hearth + VAR

1.00E-02

1.00E-01

1.00E+00

1.00E+01

1.00E+02

1.00E+02 1.00E+03 1.00E+04DEFECT INSPECTION AREA (sq mils)

EXC

EED

ENC

E(p

er m

illio

n po

unds

)

MZ(5-10in Billet)/#1 FBH

MZ(5-10in Billet)/#3 FBH

MZ (12-13in Billet)/#1 FBH

#2/#1 FBH

#2/#2 FBH

#3/#1 FBH

#3/#2 FBH

#3/#3 FBH

HA Anomaly Distribution Derivation Process

Ingot

Hard Alpha Area

#

BarDeformation

Hard Alpha Area

#

Bar Inspection #2 FBH

POD

Hard Alpha Area

#

BilletDeformation

Hard Alpha Area

#

Billet Inspection #3 FBH

POD

Hard Alpha Area

#

Forging

Hard Alpha Area

#

Forging Inspection#3 FBH

POD

Hard Alpha Area

#

Finished Part

Hard Alpha Area

#

JETQC Data

Hard Alpha Area

#

Hard AlphaFound

Hard AlphaRemaining

Hard Alpha Area

Field Calibration

POE

Hard Alpha Area

Final Distribution

POE

Hard Alpha Area

Distribution Shape

Initial Guess

#

0 103 5

1 9A

2 4 6 7 8

HA Distribution Update

Current distributions derived by RISC from complex analysis process calibrated to field experience

Details provided in 1997 SDM conference paper

TRMD/RISC effort underway to derive improved HA distributions based on new data/technology, including…

Vacuum fatigue crack growth rate behaviorImprovements in melt practice/material cleanlinessNew Probability-of-Detection curves for NDE inspectionsNew model for forging/anomaly deformationCharacterization of HA anomaly (core vs. diffusion zone)

New distributions will be calibrated to field experience

Similar work planned for anomalies in cast/wrought Ni

Deformation Modeling

Microcode to predict shape/orientation change for HA anomalies during forging has been developed and integrated into DEFORM softwareForging experiments with seeded billets conducted to validate the code

Billet to pancakeBillet to pancake to backflowBillet to pancake to final sonic shape (spin pit tests)

NDE and post-test metallography conducted to characterize defect morphology and inspectabilityRegression equations derived to predict HA deformation from fundamental forging variables

Recent Material Behavior Tasks

Vacuum fatigue crack growth dataPreviously generated on Ti-6-4, Ti-6-2-4-2, Ti-17Recently generated on WaspaloyTesting underway or planned for IN-718, P/M U720

Fatigue testing of coupons from seeded forgingsCompare test life with analytical predictionsSimilar tests planned for natural anomalies in Ni

Experimental study of Ti-17 with high oxygenDwell fatigue life debit found earlier for Ti-6242 + OSmaller (probably negligible) effect found for Ti-17 + O

Literature review of surface residual stress effectsFocus on stress relaxation, influence on FCG rates

DARWIN™ Overview

Probabilistic Fracture Mechanics

Probability of DetectionAnomaly Distribution

Finite Element Stress Analysis

Material Crack Growth Data

NDE Inspection Schedule

Pf vs. Cycles

Risk Contribution Factors

DARWIN™ Development

Version 4.0 (Alpha – Jan 2002, Production – Aug 2002)Initial version for surface damageFracture analysis for cracks at holes

Version 4.1 (Alpha – Nov 2002)Automated report generationImportance sampling confidence bounds

Version 4.2 (Alpha – Feb 2003)PC and Linux versionsExecute analysis code directly from GUI

Version 5.0 (Alpha – April 2003)Initial 3D GUIMission mixing

Version 6.0 (2004-2005)Multiple defectsAdvanced 3D capabilities

TRMD DARWIN™ Presentations

Mike Enright (SwRI)Summary of New DARWIN™ Capabilities for Surface Damage Tolerance Assessment and Related Enhancements

Luc Huyse (SwRI)Recent Probabilistic Computational Efficiency Enhancements in DARWIN™

Ahsan Jameel (Honeywell)Application of DARWIN™ to Evaluate Risk of Fracture Due to Material Anomalies in Gas Turbine Engines

Technology Transfer

DARWIN™ distribution4 TRMD partner companies evaluate extensively4 engine companies have licensed DARWIN to dateRoyalty-free license available to US Govt agencies

DARWIN useFAA certification analyses on 10+ componentsAbout 20 OEM engineers trained in use of DARWIN

DARWIN trainingNew on-line help systemAvailable for licenseesWorkshop planned at end of TRMD Phase 2 program

DARWIN and TRMD informationAvailable on DARWIN web site

Web Site: www.darwin.swri.org