Dynamic Strength - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 158

relations.of.load.components.and.correct.mean.stresses..Because.it.can.assess.
the.entire.model.of.the.structure,.hotspots.are.accurately.and.automatically.
identiied,.and.the.damage.distribution.is.easily.visualized.
Furthermore,.Virtual.Lab.Durability.provides.the.tools.to.understand.the.
causes.of.fatigue.problems.(which.events.are.the.most.damaging,.what.is.the.
contribution.of.a.load.to.a.given.hotspot).and.to.reine.the.design.of.the.com-
ponents.. Using. the. integrated. automation. scripting. methods,. the. complex.
setup.of.several.hundred.load.events.is.constructed.from.a.spreadsheet,.the.
fatigue.analysis.is.run.in.batches,.and.a.report.is.prepared.in.a.fully.auto-
mated.way.
The.unique.capabilities.of.Virtual.Lab.Durability.include.frequency-based.
fatigue. solutions. that. directly. use. random. descriptions. of. the. loads. via.
power.spectral.densities.and.phasing.information.via.cross.correlations..The.
software.also.performs.fast.simulations.of.shaker.table.tests.of.sine.sweeps.
and.block.sines.

5.10.6 Complying with Noise Regulations

To. comply. with. the. restrictive. regulations,. wind. turbine. development.
teams.have.to.perform.noise.and.vibration.analyses..The.noise.generated.
in.wind.turbines.consists.of.broadband.and.tonal.components..Broadband.
noise. mainly. originates. from. aerodynamic. phenomena. like. the. low. of.
air. around. the. blades,. hub,. and. tower.. Tonal. noise. tends. to. originate.
from. mechanical. components. and. electrical. equipment. like. the. gearbox.
and. the. generator.. The. rotation. of. these. components. and. the. resulting.
dynamic. forces. cause. local. housing. surface. vibrations,. which. distribute.
noise.to.the.surrounding.area.through.radiation..The.noise.generated.by.
driveline.rotating.machinery.also.propagates.directly.through.structural.
noise.paths.
While.it.is.relatively.easy.to.predict.performance.at.the.component.level,.
most. noise. and. vibration. problems. are. only. discovered. at. the. full. system.
level.. From. the. early. concept. development. stages. onwards,. LMS. Virtual.
Lab.Noise.and.Vibration.captures.all.critical.process.steps.to.systematically.
improve.the.noise.and.vibration.characteristics.of.a.complete.assembly..The.
loads. can. be. imported. from. measurements,. from. multibody. or. acoustic.
simulations,. or. from. generic. loading. sources.. LMS. Virtual.Lab. Noise. and.
Vibration.offers.a.wide.range.of.visualization.and.analysis.tools.to.quickly.
investigate.transfer.paths.and.eficiently.assess.the.noise.and.vibration.con-
tribution.of.individual.system.parts.

5.10.7 Optimizing the Overall Wind Turbine System Behavior

The. performance. of. advanced. mechanical. system. designs. such. as. wind.
turbines. relies. on. an. optimal. interaction. of. subsystems. of. a. different.
nature.. Wind. turbine. engineers. have. to. carefully. optimize. the. coupling.