REALTIME NONDESTRUCTIVE EVALUATION IN THE FUTURE

Frank C. Beall

University of California at Berkeley

FORECASTING

Those who have knowledge don’t predict; those who predict don’t have knowledge

Lao Tzu, 6th Century BC Chinese Poet

Outline

• Past predictions

• Assumptions for 2100

• Role of NDE

• Means of accomplishing role

Past predictions (personal)

• FPRS Plenary presentation (1988)

• NDT of Wood Symposium paper (1990)

• NDT of Wood Symposium keynote (1996)

Future of NDE of Wood and Wood-based Materials (1996)

• Megatrends

• Limitations and barriers

• Opportunities

Megatrends

• Comprehensive monitoring

• Integrated automatic systems

• Joint venture solutions

1996 Limitations and Barriers

• Low cost of wood• Fragmentation of the industry• Lack of critical mass for research• Past failures and overselling• Limitations of technologies• Harsh processing conditions• Inherent and processing defects• Variation in materials• Negative impact of moisture• Adhesive role in integrity

Future Opportunities

• Assessment of service deterioration• Surface roughness• Duration of load and creep• Treatment levels and gradients• Stress grading• Fire performance• Adhesive curing and bond quality• Curing and integrity of coatings/finishes• Accelerated aging

Assumptions for 2100

• Raw Material

• Processing

• Products

• Structures

Assumptions for 2100—Raw Material

• 80% of structural wood is from plantations• Juvenile wood is an insignificant factor for

fast-growth softwoods• Carbon credits substantially increase the

value (and cost) of wood• Some plantations produce genetically-

altered wood resistant to biodeterioration• Adhesive cost is relatively low

Assumptions for 2100—Processing

• Most processes are continuous

• Most structural material is reconstituted

• Structural grading is a minor issue

• Adhesive bonding has greater efficiency

• Non-conventional bonding for some laminates

Assumptions for 2100—Products

• Structural materials include LVL, SCL, OSB/PW, etc

• Solid wood for special appearance only

• Increased resin content for reconstituted materials

• Adhesively-bonded materials have minimal creep

STS

Assumptions for 2100—Older Structures

– Not engineered– Substantially stick-built– Have biodeterioration issues

Assumptions for 2100—New Structures

– Engineered (including residential)– Prefab/unitized construction– Fasteners for easy deconstruction– Have minimal biodeterioration issues

Roles of NDE--1

• Monitoring tree growth/stress/defects

• Verification testing of structural material and assemblies for all key mechanical properties

• Providing in-service monitoring for degradation/stress development

Roles of NDE--2

• Closed-loop feedback control for processes– Drying monitoring and control– Cutting tool performance– Adhesive curing

• Laboratory/service testing for accelerated aging

NDE Technologies

• Future technologies are currently available

• Advances will be in software and miniaturization

• Scanners with integrated technologies will be both on-line and fully portable

Means of accomplishing role

• Processing: noncontacting gauges for measuring properties on line

• Service: smart embedded sensors with indefinite lifetime (relative to lifetime of material)

Tire Pressure System

Caveat

Well, if not 2100, how about 2200?