NDE Digital Methods for Predicting Stiffness and Strength of Wind Turbine Blades - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 172

. 2.. Nondestructive. digital. test. methods. are. necessary. because. all.

destructive.testing.is.very.expensive.

. 3.. In.this.research,.we.developed.a.general.nondestructive.digital.test.

method.for.determining.the.modulus.of.elasticity.of.the.wind.tur-
bine. blades.. Reliability. results. of. more. than. 90. percent. prove. this.
method,.which.is.very.useful.for.green.alternative.technologies.

6.2 DynamicLocalMechanicalandThermalStrength

PredictionUsingNDTforMaterialParameters
EvaluationofWindTurbineBlades
6.2.1 Introduction

As.stated.above,.the.ability.of.ultrasound.waves.to.travel.in.a.web.direction.
over.a.minimum.of.time.for.curing.iberglass.was.advanced.by.the.author.in.
1966. 1 .This.effect.can.be.used.for.different.applications,.such.as.composites,.
ceramics,.and.metal.alloys..However,.only.the.combination.of.thermographs,.
ultrasound,.and.radiography.techniques.can.predict.the.physical.parameters.
of.a.material.(density,.thickness,.modulus.of.elasticity,.and.strength).
The.properties.of.carbon—carbon.composites.are.shown.in.Table.6.6..The.
parameters. of. the. relationship. to. strength. for. carbon—carbon. composites.
are.shown.in.Table.6.7.
The.overall.approach.is.to.determine.the.local.elastic.constant.and.material.
parameters.using.nondestructive.methods,.which.characterize.strength.in.the.
domain.point.and.also.determine.the.local.stresses.from.the.temperature.proile.
The.purpose.of.this.research.is.to.show.and.discuss.the.developed.NDE.
methods.used.to.increase.the.reliability.estimation.of.dynamic.strength.
The.thermal,.radial,.and.tangential.stresses.for.an.orthotropic.nose.were.used.
as.an.example.while.the.dynamic.modulus.of.elasticity.for.stress.analysis.was.
used.and.all.the.stress.components.for.strength.criteria.were.established. 4,10,11
Agfa. Nondestructive. Testing,. Inc.. (Lewistown,. Pennsylvania),. after. suc-
cessfully. testing. caps. for. three. years. using. the. ultrasound. method,. has.
become.a.leading.supplier.of.NDT.systems. 12
Composites. structures. for. space. programs. have. been. mainly. manufac-
tured. from. sandwich. composites. with. aluminum. honeycomb. and. graph-
ite/epoxy.face.sheets.and.are.located.on.the.upper.part.of.the.space.vehicle.
launcher.where.their.inluence.has.the.largest.effect. 13
For.example,.the.inluence.rates.of.composites.on.different.stages.varies.on.
the.Ariane.5.rocket.from.7.percent.for.the.lateral.booster.to.100.percent.for.
the.upper.parts..They.require.that.a.strong.effort.be.made.in.the.design.of.
structures.in.the.launcher.upper.part.and.the.demand.for.NDT.equipment.
and.procedures.becomes.imperative.