This presentation overviews aThis presentation overviews a teaching module which was developed through an ASNT

Faculty GrantFaculty Grant

• PowerPoint presentation (to be presented)• PowerPoint presentation (to be presented)• Description of supporting material related

to NDT methods and Materials Durabilityto NDT methods and Materials Durability• Additional supporting items

A N D i P P diA New Design Process Paradigm: Sustainable System Design

• Brief Historical Context

• Traditional Design Paradigm

Why owners/managers should be flogged!• Why owners/managers should be flogged!

• A Better Paradigm

f C f

• Additional background

Developed by Virginia Tech Professor John C. Duke, Jr. with support of a Faculty Grant of the American Society for Nondestructive Testing, Inc.

Why Sustainable System Design?Why Sustainable System Design?

• Numerous major systems are in-service beyondNumerous major systems are in service beyond the original design life because replacement of these systems is not a high priority.

• Systems operated beyond their service life behave unpredictably and are difficult to manage.

• Maintenance of systems in use beyond their i lif i l b iservice life is costly because it was not

anticipated during the planning and design processprocess.

Critical Systems Beyond Their S i LifService Life

Roman Aqueducts

Curator Aquarum was responsible for designing and planning so the aqueducts could be maintained.

2008 Infrastructure Renewal Price Tag2008 Infrastructure Renewal Price Tag

• Worldwide estimatesWorldwide estimates $53,000,000,000,000 ($53T)

• US estimates within the next 5 years $1 500 000 000 000 ($1 5T)$1,500,000,000,000 ($1.5T)

“those who ignore history are doomed to repeat it ”repeat it…

• For the most part traditional engineeringFor the most part traditional engineering design has resulted in systems which perform well during the intended serviceperform well during the intended service life.

• For the most part these systems are in use• For the most part these systems are in use beyond the intended service life.N dl t th t t• Needless to say these systems were not designed to be maintain in service beyond th i t d d i lifthe intended service life.

Traditional Engineering DesignTraditional Engineering Design

• Philosophy general – design make surePhilosophy general design, make sure it’s built as designed, operates as designed do minor maintenancedesigned, do minor maintenance, decommission

• Philosophy specific select materials• Philosophy specific – select materials based on specified performance limits, size the components so that the stresssize the components so that the stress levels avoid overload or failure due to fatigue or environmental effectsfatigue or environmental effects

It is suggested that the instructor show an episode or portion of an episode of the National Geographic World’s Toughest Fixes in order to emphasize the magnitude of the effort required to repair major systems. Encourage the students to look for ways that the design might have been altered to facilitate such repair as well as ways to monitor the system to provide an early warning of the need for repair.

Traditional design mindsetg• Creating a system which will not fail during the

established service periodestablished service period.• Avoid issues with difficult to access components.

D t il f d d l t i l t i• Details of damage development irrelevant since by design they will not become important until after the service lifeafter the service life.

• Maintenance is limited to minor issues such as replacing light bulbs or changing lubricants.replacing light bulbs or changing lubricants.

In the USA most major systems are d i d d b ilt fdesigned and built for an owner.

Designer/builder Owner/operatorDesigner/builder• Aircraft manufacturer• Power plant construction

Owner/operator• Airline operator• Utility operatorPower plant construction

contractor/system manufacturerM h i l t t f

Utility operator• Municipality/water

authority• Mechanical contractor for

water distribution systems

I th USA th / t iIn the USA the owner/operator is responsible for maintenance, which is

i t d d t b i d i th i lifintended to be minor during the service life.

Since we are designing to avoid failure our mechanical testing is conducted to supportmechanical testing is conducted to support this approach. • Components areComponents are

sized to limit the stress below strength limits. (uniaxial tension)

• Components are sized to lower the stress so the cycles in service can be

7075-T6 Al

service can be accommodated. (S-N curve)

Our properties databases offer no insight into when and where degradation occurs even though e a d e e deg adat o occu s e e t oug

technology exists to detect and track it.

Life: 1 1 million cyclesLife: 1.1 million cycles(N=0 failure )

50 μm50 μm

Traditional Design ProcessTraditional Design Process• Define Functional Requirements• Formulate Initial ConceptFormulate Initial Concept• Assess with respect to Service Requirements

– Derive requirements for materials– Determine subcomponentsDetermine subcomponents

• Revise Initial Concept– Reassess with respect to Service Requirements

• Refine materials selectionRefine materials selection• Real or Virtual Prototype Trials• Refine Concept• Develop Manufacturing Process(es)• Develop Manufacturing Process(es)• Refine Concept & Manufacturing• Begin Production

Traditional Scheme

Requirements• capabilities

Quality Assurance NDI+

Commissioning NDI to support minor maintenance

Planning

• capabilities• service life

Commissioning pp

&Design

Fabrication Operation/Service

C t i tC

ondi

tionConstraints

• cost• environment

Design Life

C

Why owners/managers should be fl d!flogged!

• Traditional design expects that once theTraditional design expects that once the system, structure, or component reaches the design life it will be replacedthe design life it will be replaced.

• Invariably owners/managers observe that many critical costly systems are stillmany critical, costly systems are still functioning at the design life … so why not continue to use them LIFE EXTENSIONcontinue to use them… LIFE EXTENSION

• You don’t extend life you extend USE!!!

Traditional Scheme w/Life Extension

Requirements• capabilities

Quality Assurance NDI+

Commissioning NDI to support minor maintenance

Planning

• capabilities• service life

Commissioning

&Design

Fabrication Operation/Service

C t i t Region not well definedC

ondi

tionConstraints

• cost• environment

Region not well defined so it was avoided with the original design

Design Life Life Extension

C

Note- The “Condition” plot is hypothetical since typically the condition is not being monitored.

Overlooked Consequences of Use-Extension

• Assessing systems to justify Use-Extension is especially g y j y p yexpensive since the design did not anticipate this need.– Some components may be inaccessible so it is not

ibl t d t i th i t ditipossible to determine their current condition• Assessing components prior to the formation of cracks

which can be reliably detected is not currently possiblewhich can be reliably detected is not currently possible so remaining useful life is difficult to estimate.

• Detailed assessment of degradation is needed to d t i h it ill b ff t d b th tidetermine how it will be affected by the operating environment.

A Better Paradigm in Light of RealityA Better Paradigm in Light of Reality

• Consider maintenance and associated inspection pduring the initial planning and design phases--- why and when do materials degrade and components start to fail?

Sustainable Design-The details• Define Functional Requirements• Formulate Initial Concept

g

p• Assess with respect to Service Requirements

– Derive requirements for materialsId tif th h i l th l d h i l i t• Identify the chemical, thermal, and mechanical environment

• Establish how the materials will degrade– Determine subcomponents

Identify damage modes that should be expected for these• Identify damage modes that should be expected for these materials under these environmental conditions

• Provide accommodation, where appropriate, for monitoring technology

– Determine that maintenance and associated inspection can be accomplished reliably and cost-effectively

The details (continued)The details (continued)

• Revise Initial Conceptp– Reassess with respect to Service Requirements

• Refine materials selection• Real or Virtual Prototype TrialsReal or Virtual Prototype Trials• Refine Concept• Develop Manufacturing Process(es)p g ( )• Refine Concept & Manufacturing

– Assure that design changes to facilitate manufacturing do not negatively impact maintenancemanufacturing do not negatively impact maintenance and associated inspection

• Begin Production

Requirements• capabilities Commissioning

Planning&

capabilities

F b i tiOperation/Service

&&Design

Fabrication &Maintenance

Constraints

Con

ditio

n

Constraints• cost• environment

Health Management Plan

S t i bl

CHealth Management Plan• Deterioration Processes• Inspection Requirements• Health Monitoring Requirements

Sustainable Design

• Maintenance• repair• replacement Design

Summaryy• Current engineering design generally does not

see the need for NDT after the system issee the need for NDT after the system is properly built and placed into service.

• Design based on fixed service-life is the ideal gbut not the reality.

• The design approach taught in colleges of engineering must change to consider maintenance and NDE during the planning and d i hdesign phase.

• The purpose of this module is to start this process for engineering design coursesprocess for engineering design courses.

Elements to support sustainable d i d idesign education

• Material Science– Properties– Modes of degradation

• Manufacturing Processes and d f tdefects

• Mechanical Behavior– Fatigue

Fracture

SensingEnergy

– Fracture– Creep

• NDE capabilities– Method capabilitiesEnergy – Method capabilities– Reliability (POD, POI, POF)– Interaction of probing energy

with material degradation

Modes of DegradationModes of Degradation• Instructors may want to consider placing

“Materials Degradation and Its Control byMaterials Degradation and Its Control by Surface Engineering,” by Batchelor et. al. Imperial College Press on reserve for theirImperial College Press on reserve for their students. The authors devote the 1st part of the book, written at a very introductory level, to a discussion of the following topics causing materials degradation:– Mechanical– Chemical

Thermal and radiation– Thermal and radiation– Combinations

Materials degradation- mechanicalMaterials degradation mechanical

• Mechanical causesMechanical causes– Wear

• Abrasion• Abrasion• Erosion

– CreepCreep– Fatigue– Fracture– Fracture

Materials degradation- chemicalMaterials degradation chemical

• Corrosion of metalsCorrosion of metals• Oxidation reactions with oxygen, sulphur and

halogensg• Softening/embrittlement of wood and polymers• Corrosion of concrete and ceramicsCorrosion of concrete and ceramics• Dissolution of metals and ceramics in liquid

metals and inorganic salts and alkaliseta s a d o ga c sa ts a d a a s• Biochemical and biological modes

Materials degradation –Thermal and Radiation

• Thermal degradationThermal degradation– Elevated

Cryogenic temperatures– Cryogenic temperatures• Photochemical• High energy radiation

Materials degradation –synergistic effects

• Wear in a chemically active environmentWear in a chemically active environment– Corrosive-abrasive

Corrosive effects on fretting– Corrosive effects on fretting– Abrasive wear in liquid metals

C i f ti d f t• Corrosion fatigue and fracture• Corrosive embrittlement

Modes of detecting degradationModes of detecting degradation

• Instructors may wish to place on reserve copiesInstructors may wish to place on reserve copies of the NASA Special Publication SP-5113, the ASM Materials Handbook volume on Nondestructive Testing, and the American Society for Nondestructive Testing Handbook S iSeries.

• The Table-Comparison of Selected NDE Methods (derived from NASA SP 5113) shouldMethods (derived from NASA SP-5113) should be distributed to the students as a reference.

Modes of detecting degradation – mechanical NDT

• UltrasoundUltrasound• Acoustic Emission• Acousto-ultrasoundAcousto-ultrasound• Dial gage• Liquid Penetrant• Liquid Penetrant• Impact echo• Impulse response• Impulse response• Resonance

Modes of detecting degradation-electromagnetic NDT

• Magnetic particles• Magnetic flux leakage• Electrical resistance

Edd t• Eddy current• Infrared thermography• Microwave/radar• Microwave/radar• Radiography X&N• Optical Fiber gagesOptical Fiber gages• Resistance Strain gage• LVDT• Visual

Modes of detecting degradation-practical issues

Selection of appropriate nondestructive methods depends pp p pon:

• The nature of the degradation• The process for analyzing the characterization data

collected• Constraints associated with the specific application• Constraints associated with the specific application

– Access– Environment– Critical imperfection size– Etc.

Discipline Experts to support Sustainable design

Planning and design teams typically consult discipline g g yp y pexperts for in depth input regarding aspects of the design. Examples of discipline experts:

St t l l i– Structural analysis– Loads associated with operation– Materials– Materials

Since it is unrealistic to expect all design engineers to have strong background knowledge of materials degradation and the associated methods for detecting and tracking it a new discipline expert is needed- NDE Engineer.

Case StudiesCase Studies

-- It has been reported that Boeing has designed theIt has been reported that Boeing has designed the Dreamliner aircraft so that it can be sustained indefinitely

-- Turbine Engine Manufacturers use an approach somewhat similar– see the presentation by Ward Rummel and Carlos Pairazaman “Inspection based Life Management of Fracture Critical Engine Components”g g p

-- Examples of problems which might have been avoid by designing for inspectablity are overviewed in the lecture

i t ith t “D i f I t bilit ”powerpoint with notes “Design for Inspectability”