Structural Health Monitoring and Its Role in Affordability of detectable Fatigue damage Fatigue damage Mandatory SB modifications and inspections ... Boeing Research & Technology |

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Boeing Research & Technology

Structural Health Monitoring and Its Role in Affordability

10th International Workshop on Structural Health Monitoring

Stanford University

2 September 2015

Naveed Hussain

Vice President, Aeromechanics Technology

Boeing Research & Technology

Author, 9/2/2015, Filename.ppt | 1


Boeing Research & Technology | Aeromechanics

Boeing Products

787

767

747

717

777737

C-17

F/A-18

P8

TankersPhantom Eye

V-22


SLS



Increased Performance Drives Design Complexity

Mission durations from hours to days

Payloads from thousands to millions of lbs

Data from notebooks to Giga Bytes

Life from years to decadesAuthor, 9/2/2015, Filename.ppt | 3



Complexity Increases Sustainment Needs and LCC

▪ The Comet failure in 1954 showed that static loading and a factor of safety

was not sufficient to assure safe life of a pressurized aircraft

▪ The failure of 5 B47’s with less than 2500 hours each resulted in a

disciplined aircraft structural integrity program to ensure airframe design

life requirements

▪ In 1969 an F111 failure due to a rogue manufacturing flaw illustrated a

need for a damage tolerant design and certification philosophy

Comet

Fatigue

B-47

ASIP begins

F-111

Damage Tolerance




Manufacturer’s Design Requirements & Objectives

Each arrow represents a

Typical safety subject / ruleDesign

requirements

and objectives

(DR&O)

Final drawings

Regulatory standards

(FARs, JARs)

The DR&O Meets or Exceeds All Regulatory Requirements

The Final Design Meets or Exceeds the DR&O

What are the effects of change on economics and reliability?


Safety

Wheel



Current Structural Maintenance and Inspection System for Commercial Airplanes

It is a regulatory requirement that operators have an approved baseline maintenance and inspection program for each airplane fleet

New technology must accommodate maintenance and inspection requirements with

the same or better reliability in a more cost effective manner

Years of service

Fleet damagerate

Environmental deteriorationand accidental damage

Corrosion inspections

Scheduled maintenance checks

Supplemental Structural inspections (MPD sec 9)

Fatigue damageStart of detectable Fatigue damage

Mandatory SB modifications and inspections

Inspection of repairs

Widespread Fatigue Damage




•Reduced Redundancy

•Lower Weight/Cost

•Increased Safety

Flight Controls



•Increased Safety

Flight Controls

•Reduced QA Inspections

& System Checkout Time

•Reduced Flight Test &

Certification Time & Cost

•Reduced Support

Equipment

•Reduced Initial Spares

Other





•Reduced Support

Equipment


Other



Avionics



Avionics•Reduced Redundancy

•Increased Safety


Electrical / Wiring


•Increased Safety


Electrical / Wiring

•Increased Allowables


•Increased Performance

Structures




Structures


•Improved Electrical Power

Generation Efficiency


Propulsion/APU





Propulsion/APU



•Increased Safety

Fuel



•Increased Safety

Fuel



•Increased Safety

Landing Gear



•Increased Safety

Landing Gear



•Increased Safety

Hydraulics



•Increased Safety

Hydraulics



ECS



ECS



•Increased Safety

Flight Controls



•Increased Safety

Flight Controls





•Reduced Support

Equipment

Other





•Reduced Support

Equipment

Other



Avionics



Avionics


•Increased Safety


Electrical / Wiring


•Increased Safety


Electrical / Wiring




Structures




Structures





Propulsion/APU





Propulsion/APU



•Increased Safety

Fuel



•Increased Safety

Fuel



•Increased Safety

Landing Gear



•Increased Safety

Landing Gear



•Increased Safety

Hydraulics



•Increased Safety

Hydraulics



ECS



ECS

Improved

Mission

Reliability

Improved

Availability

Reduced

Life Cycle

Cost



•Increased Safety

Flight Controls



•Increased Safety

Flight Controls





•Reduced Support

Equipment


Other





•Reduced Support

Equipment


Other



Avionics



Avionics


•Increased Safety


Electrical / Wiring


•Increased Safety


Electrical / Wiring




Structures




Structures





Propulsion/APU





Propulsion/APU



•Increased Safety

Fuel



•Increased Safety

Fuel•Increased Allowables


•Increased Safety

Landing Gear



•Increased Safety

Landing Gear



•Increased Safety

Hydraulics



•Increased Safety

Hydraulics



ECS



ECS

Integrated Vehicle

Health

Management

(IVHM) Solutions

IVHM Value Proposition

Improved

Operational

Plans

Efficient

Supply

Chain

Enhanced

Design

Structures is one of a number of

subsystems and must be integrated

at the system level




Structural Health Management Approach

=

IMPROVED

RELIABILITY

INCREASED

PERFORMANCE

DECREASED

Life Cycle Costs

SHM is an evolution to the design process by introducing new technology and criteria that increase the structural knowledge throughout a product’s lifecycle

and therefore better predict life cycle cost drivers in time to minimize them

Structural Design

hot spot

Problem Areas

Identified

Inspection Schedule

Constructed

Analysis and Testing

737-400 Maneuver Spectra Comparison

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

Incremental Vertical CG Acceleration (g's)C

um

ula

tive O

ccurr

ences p

er

1000 fli

ghts

Boeing Book 2

737 All Airplanes

+

FIRST-HAND KNOWLEDGEusage

damage

environments




SHM System Design Approach to Drive Requirements that Address Decisions that Reduce LCC

Data

Collection

Data

Processing

Decision

Making &

Dissemination

Information Processing to

Define Current State

Sensors

Data

Acquisition

Hardware A1

A2

An

Data

Fusion

&

Integration

Material

StateCapability

analysis

Maintenance &

Operations

Recommendations

Visual InspectionA1, A2, An = Multiple algorithms

for SHM information processing

data information knowledge decision

NDI/NDE

Other Data

(reports of damage

events, fleet history …)

Loads and

EnvironmentsEnvironmental

State

Margins

PrognosisManufactured

State


…



Quantifying AffordabilitySimplified Cost Benefit Model

Operating

benefits

NPV

Product costs

Nonrecurring

build costs

Recurring

build costs

Support

training

Weight and

power costs

Recurring

operational

cost

System

development

and design

Development

testingCertification

Software

development

Technology

development

Design

engineering

Increase

availability

Reduce

schedule

interrupts

Reduce

support costs

Reduce

maintenance

labor

Increased

Performance

Operator

introduction




SHM Cash Flow is a Key Driver for AffordabilityOperational Damage Monitoring Example

▪ Increased life cycle capabilities can bring cash flow earlier into a products life cycle

▪ Incorporation as part of life cycle design

▪ Improved performance and reduced sustainment costs

▪ Manufacturing monitoring

▪ Better insight into anomalies and reduced redesign costs

Product value

Year

$



SHM Vision

2015-2020• SHM Confidence Building

• SHM Expanded Area

Damage Detection

• SHM for Corrosion

• Multi-Scale Physics Based

Prognosis

• Virtual Life ExtensionAccidental Damage

Broad area autonomous diagnostic and

repair system as part of integrated design

Broad area

sensing

Flight parameter load monitoring

Present• NN Based Load Monitoring

• Hot Spot Damage Detection

• Bayesian Data Fusion/Prognosis

• Accidental Damage Monitoring

• Risk Enabled CBM+SI

In-Situ Fatigue Crack Monitoring Multi-Scale Material modeling and

prognostics

Real-Time Impact

monitoring

?

Diagnosis

Maintenance

Actions

Prognosis

2020+• Broad Area Diagnostics and

Diagnostics

• Identification of “Unknown

Unknowns”

• Reliability Based Design

• Bio-Inspired Sensing and Self-

Healing Materials

• Fly-by-Feel Vehicles

• Operational Mission Space

ExpansionVsink

VEαε

1

ε2 εnΦ, Φ




Enhancing an Inspection Based Paradigm

Can operational usage knowledge be used to change inspection

criteria and improve design, manufacturing, and maintenance

efficiency (reduced life cycle costs) ?

CR

AC

K L

EN

GT

H

NUMBER OF

FLIGHTS

N N N N

N Based on

Design Load

Spectrum N N N N

N1 N2 N3N3N1, N2, … Based on

Operational LoadsN4

Critical crack length (allowable damage)

NDI

detectable

crack length

Crack Initiation (Durability) Crack Propagation/ Damage Tol.





GOALS - Reduce aircraft schedule interrupts by:

1. Reducing number of falsely reported hard landings

2. Aiding the maintenance process

PHASE 2 APPROACH

• Pilot “by feel” initiated inspection

• Flight data and limited sensor information

used to predict loads

• Recommend maintenance action

• Aid maintenance procedure

AUTOMATED

LOAD PREDICTION

PHASE 1 APPROACH


• Flight data provided

• Lookup table used to determine

maintenance action

ENHANCED MAINTENANCE INFORMATION

787 Maintenance Manual

GW < MLW+10K

Sink < 5 Sink <8

Pitch Angle <10 <10

Crab Angle <5 <3

Roll Angle <4 <2

Roll Rate <8 <4

Initial CG NZ >.9 >.95

Peak CG NZ <1.5 <2.0

CURRENT APPROACH


• Limited flight data usage with AMM

• Large number of false positives

787 Maintenance Manual

GW < MLW

Roll Angle <2

Peak CG NZ <1.9

MAINTENANCE INFORMATION

INSPECTION

LOADS

LOAD

PREDICTION

MODEL

FLIGHT

PARAMETERS

SENSOR

DATA

LOADS

LOAD

PREDICTION

MODEL

FLIGHT

PARAMETERS

SENSOR

DATA

LOAD

PREDICTION

MODEL

FLIGHT

PARAMETERS

SENSOR

DATA

Hard Landing Detection Capability Demonstrates Basic Load Monitoring System

GOOD

BETTER

BEST



Flight and user

demo

Multistage Approach for System V&V

6 5 4 3 2 1

14 13 12 11 10 9 8 7

24

23

6 5 4 3 2 1

14 13 12 11 10 9 8 7

23

24

15

16

17

18

19

20

21

22

19

20

21

22

WARNING: This document may contain information whose export is restricted by the Arms Export Control Act (Title 22, U.S.C. SEC 2752, et seq.) or the

Export Administration Act of 1979, as amended, Title 50, U.S.C., App 2401 et seq. This information may not be exported, released or disclosed to foreign

persons, whether in the United States or abroad, unless the export, release or disclosure is in full compliance with these statutes. Violations of these statutes

are subject to severe penalties.

C1

FACE

C2 (only for sp41)

C1 (only for sp41)

FACE

Side

Increased multi-physics and multi-scale simulation with limited testing

improves design optimization for significantly less cost and development time


Sensor

Actuator

Sensor

Actuator



Weight Reduction via SHM-Enabled Design Criteria

Acoustic

Emission

DAQ

Laptop

Computer

Preamp

Coaxial cable

Impact

location

Impact generated

waves detected

n x

sensors

… n x

channels

Lead cable

Interface

panel

SHM System

SHM-based damage tolerance approach to enable significant weight savings by

reducing conservatism associated from damage uncertainty




Summary of Key Challenges

DATA

• Light weight broad

area monitoring

• Relational data base

technology for

maintenance and

management

• Data mining

methods to optimize

PDF development

INFORMATION KNOWLEDGE DECISION

• Disparate source

data mining and

fusion in the context

of structural criteria

• Process based cost

modeling to assess

application benefit

• Culture:

multidisciplinary,

collaborative

optimization

methodology

• Multi-scale modeling

integrated with

monitoring

information

• Open system

architecture for

better integration of

capabilities and

knowledge

• Cradle to grave

knowledge integral

with design

optimization

• Expert system

development

coupled with DR&O

and certification

criteria development

• Open system

architecture for

platform awareness

• Decision process

integral with design

optimization in

terms of life cycle

cost optimization

Technology challenges exist at all stages of an SHM design process



Documents

Structural Health Monitoring and Its Role in Affordability of detectable Fatigue damage Fatigue damage Mandatory SB modifications and inspections ... Boeing Research & Technology |