Benchmarks - Revision history

MKuts at 08:41, 29 September 2021

2021-09-29T08:41:37Z

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MKuts at 15:03, 28 September 2021

2021-09-28T15:03:02Z

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	<gallery heights=250px widths=300px>		<gallery heights=250px widths=300px>
	~~File:~~File:Interfacedesign.png\|Interface Geometries		File:Interfacedesign.png\|Interface Geometries
	~~File:~~File:Far-Field.png\| Far-field effects		File:Far-Field.png\| Far-field effects
	~~File:~~File:Curved.png\|Curved Interface		File:Curved.png\|Curved Interface
	File:Thin.png\| Thin Geometry		File:Thin.png\| Thin Geometry
	</gallery>		</gallery>

Jadmin: /* The Ampair 600 Wind Turbine */

2021-09-28T13:05:33Z

The Ampair 600 Wind Turbine

Jadmin: /* The Brake-Reuß Beams */

2021-09-28T12:53:28Z

The Brake-Reuß Beams

← Older revision		Revision as of 08:53, 28 September 2021
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	This beam has been extensively studied, experimentally and numerically, at the 2014-2016 [[Research_Camps\|NOMAD]] and 2017-2020 [[Research_Camps\|TRC]].		This beam has been extensively studied, experimentally and numerically, at the 2014-2016 [[Research_Camps\|NOMAD]] and 2017-2020 [[Research_Camps\|TRC]].
			[[File:BRB.png\|thumb\|Geometry of the BRB benchmark]]

	=== Variations ===		=== Variations ===
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	The geometry of the BRB started to be modified starting in 2016. The first modifications were of the interface geometry, where the flat lap joint was modified to have: Hertzian Contact, a Small Pad (equivalent to a standard washer), a Large Pad (equivalent to an oversized washer), and a Reverse Pad (where the oversized washer material was removed of the interface and the bolted connections)<ref name =" InterfaceGeom"/>. At the same time, the far-field effects were studied; the beam was modified to be longer (an additional 6" of material on each end), and removing material from the original length to create a spring-like structure<ref name= "FarField"/>. In 2017, the flat interface was then modified to have a curved geometry, simulating poor machining practice/ machine error<ref>I. Lawal, S. Shah, M. Gonzalez-Madrid, T. Hu, C W. Schwingshackl, and M. R. W. Brake, "The Effect of Non-Flat Interfaces on System Dynamics," IMAC XXXVI A Conference and Exposition on Structural Dynamics, Orlando, FL, February, 2018.</ref><ref>W. Chen, M. Jin, I G. Lawal, M. R. W. Brake, and H. Song, "Measurement of Slip and Separation in Jointed Structures with Non-Flat Interfaces," Mechanical Systems and Signal Processing, 134, pp 106325 (1-22), 2019.</ref>. In 2019, the beam was modified to have a 1" x 1/2" x 28" geometry (the reduction is parallel to the joint interface), to enable easier measurements using DIC<ref>M. Cenedese, M. Jin, G. Kosova, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, J. P. Noel, and S. Nagarajaiah, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part II Data Analysis," Tribomechadynamics 2019, Houston, TX, August, 2019.</ref><ref>D. Jana, W. Chen, A. Singh, M. Jin, G. Kosova, M. Cenedese, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, J. P. Noel, and S. Nagarajaiah, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part I Experimental Investigation," Tribomechadynamics 2019, Houston, TX, August 2019.</ref><ref>A. Singh, W. Chen, D. Jana, M. Jin, M. Cenedese, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, and J.-P. Noël, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part 1 Experimental Investigation," IMAC XXXVIII A Conference and Exposition on Structural Dynamics, Houston, TX, February, 2020.</ref><ref>G. Kosova, M. Jin, M. Cenedese, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, and J.-P. Noël, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part II Analysis," IMAC XXXVIII A Conference and Exposition on Structural Dynamics, Houston, TX, February, 2020.</ref><ref>M. Jin, G. Kosova, M. Cenedese, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, S. Nagarajaiah, K. J. Moore, and J.-P. Noel, "Nonlinear Identification of a Jointed Structure Using Full-Field Data Part II – Analysis," Mechanical Systems and Signal Processing, under review.</ref><ref>W. Chen, D. Jana, A. Singh, M. Jin, M. Cenedese, G. Kosova, M. R. W. Brake, C. W. Schwingshackl, S. Nagarajaiah, K. J. Moore, and J.-P. Noel, "Nonlinear Identification of a Jointed Structure Using Full-Field Data Part I – Experimental Investigation," Mechanical Systems and Signal Processing, under review.</ref>. Finally, one side of the beam was Additively Manufactured and shortened; this allowed the study of adding internal vibration absorbers and their effects on the response of the joint <ref> H. Shu, S. A. Smith, and M. R. W. Brake, "The Influence of Additively Manufactured Nonlinearities on the Dynamic Response of Assembled Structures," ASME Journal of Vibration and Acoustics, 142, pp 011019-1-9, 2020.</ref>.		The geometry of the BRB started to be modified starting in 2016. The first modifications were of the interface geometry, where the flat lap joint was modified to have: Hertzian Contact, a Small Pad (equivalent to a standard washer), a Large Pad (equivalent to an oversized washer), and a Reverse Pad (where the oversized washer material was removed of the interface and the bolted connections)<ref name =" InterfaceGeom"/>. At the same time, the far-field effects were studied; the beam was modified to be longer (an additional 6" of material on each end), and removing material from the original length to create a spring-like structure<ref name= "FarField"/>. In 2017, the flat interface was then modified to have a curved geometry, simulating poor machining practice/ machine error<ref>I. Lawal, S. Shah, M. Gonzalez-Madrid, T. Hu, C W. Schwingshackl, and M. R. W. Brake, "The Effect of Non-Flat Interfaces on System Dynamics," IMAC XXXVI A Conference and Exposition on Structural Dynamics, Orlando, FL, February, 2018.</ref><ref>W. Chen, M. Jin, I G. Lawal, M. R. W. Brake, and H. Song, "Measurement of Slip and Separation in Jointed Structures with Non-Flat Interfaces," Mechanical Systems and Signal Processing, 134, pp 106325 (1-22), 2019.</ref>. In 2019, the beam was modified to have a 1" x 1/2" x 28" geometry (the reduction is parallel to the joint interface), to enable easier measurements using DIC<ref>M. Cenedese, M. Jin, G. Kosova, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, J. P. Noel, and S. Nagarajaiah, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part II Data Analysis," Tribomechadynamics 2019, Houston, TX, August, 2019.</ref><ref>D. Jana, W. Chen, A. Singh, M. Jin, G. Kosova, M. Cenedese, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, J. P. Noel, and S. Nagarajaiah, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part I Experimental Investigation," Tribomechadynamics 2019, Houston, TX, August 2019.</ref><ref>A. Singh, W. Chen, D. Jana, M. Jin, M. Cenedese, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, and J.-P. Noël, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part 1 Experimental Investigation," IMAC XXXVIII A Conference and Exposition on Structural Dynamics, Houston, TX, February, 2020.</ref><ref>G. Kosova, M. Jin, M. Cenedese, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, and J.-P. Noël, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part II Analysis," IMAC XXXVIII A Conference and Exposition on Structural Dynamics, Houston, TX, February, 2020.</ref><ref>M. Jin, G. Kosova, M. Cenedese, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, S. Nagarajaiah, K. J. Moore, and J.-P. Noel, "Nonlinear Identification of a Jointed Structure Using Full-Field Data Part II – Analysis," Mechanical Systems and Signal Processing, under review.</ref><ref>W. Chen, D. Jana, A. Singh, M. Jin, M. Cenedese, G. Kosova, M. R. W. Brake, C. W. Schwingshackl, S. Nagarajaiah, K. J. Moore, and J.-P. Noel, "Nonlinear Identification of a Jointed Structure Using Full-Field Data Part I – Experimental Investigation," Mechanical Systems and Signal Processing, under review.</ref>. Finally, one side of the beam was Additively Manufactured and shortened; this allowed the study of adding internal vibration absorbers and their effects on the response of the joint <ref> H. Shu, S. A. Smith, and M. R. W. Brake, "The Influence of Additively Manufactured Nonlinearities on the Dynamic Response of Assembled Structures," ASME Journal of Vibration and Acoustics, 142, pp 011019-1-9, 2020.</ref>.

			<gallery heights=250px widths=300px>
			File:File:Interfacedesign.png\|Interface Geometries
			File:File:Far-Field.png\| Far-field effects
			File:File:Curved.png\|Curved Interface
			File:Thin.png\| Thin Geometry
			</gallery>

	=== Main features ===		=== Main features ===
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	-->		-->

	== Referenses ==		== Referenses ==
	<references />		<references />

Jadmin at 12:47, 28 September 2021

2021-09-28T12:47:18Z

← Older revision		Revision as of 08:47, 28 September 2021
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	== The Brake-Reuß Beams ==		== The Brake-Reuß Beams ==
	=== Description ===		=== Description ===
			The Brake-Reuß Beam, also known as the BRB, is a simple beam with a three-bolt lap joint at its center. The beam was designed by M. R. W. Brake, P. Reuß, D. J. Segalman, and L. Gaul<ref name = "BRBorig">M. R. W. Brake, P. Reuß, D. J. Segalman, and L. Gaul, "Measurements and
			modeling of variability and repeatability of jointed structures with frictional interfaces," in IMAC XXXII A Conference and Exposition on Structural Dynamics, (Orlando, FL), February 2014.</ref> as a simple system with strong nonlinearity. The simple geometry of the beam is a 1" x 1" x 28" (25 mm x 25 mm x 72 cm) piece of stock material, typically 304 Stainless Steel. The geometry and design of the beam allow for most of the modes to be separate, with only torsional ones being close to some of the bending ones.

			This beam has been extensively studied, experimentally and numerically, at the 2014-2016 [[Research_Camps\|NOMAD]] and 2017-2020 [[Research_Camps\|TRC]].

	=== Variations ===		=== Variations ===
			Throughout the years, the BRB has been modified to have various geometries. In the original work by Brake et al. <ref name=" BRBorig"/> the beam was made using stock material available in Germany (25 mm x 25 mm x 72 cm). Then in the 2014 - 2016 NOMADs<ref> S. Smith, J. C. Bilbao-Ludena, S. Catalfamo, M. R. W. Brake, P. Reuß, and C. W. Schwingshackl, "The Effects of Boundary Conditions, Measurement Techniques, and Excitation Type on Measurements of the Properties of Mechanical Joints," Cham, 2016: Springer International Publishing, in Nonlinear Dynamics, Volume 1, pp. 415-431. </ref><ref>L. Salles, C. Swacek, R. M. Lacayo, P. Reuss, M. R. W. Brake, and C. W. Schwingshackl, "Numerical Round Robin for Prediction of Dissipation in Lap Joints," Cham, 2016: Springer International Publishing, in Nonlinear Dynamics, Volume 1, pp. 53-64.</ref><ref> S. Catalfamo et al., "Effects of Experimental Methods on the Measurements of a Nonlinear Structure," Cham, 2016: Springer International Publishing, in Dynamics of Coupled Structures, Volume 4, pp. 491-500. </ref> <ref>S. A. Smith, M. R. W. Brake, and C. W. Schwingshackl, "On the Characterization of Nonlinearities in Assembled Structures," Journal of Vibration and Acoustics, vol. 142, no. 5, 2020, doi: 10.1115/1.4046956.</ref><ref> J. Gross et al., "A Numerical Round Robin for the Prediction of the Dynamics of Jointed Structures," Cham, 2016: Springer International Publishing, in Dynamics of Coupled Structures, Volume 4, pp. 195-211. </ref><ref>M. S. Bonney, B. A. Robertson, M. Mignolet, F. Schempp, and M. R. Brake, "Experimental Determination of Frictional Interface Models," Cham, 2016: Springer International Publishing, in Dynamics of Coupled Structures, Volume 4, pp. 473-490. </ref><ref> M. R. W. Brake, J. G. Stark, S. A. Smith, D. P. T. Lancereau, T. W. Jerome, and T. Dossogne, "In Situ Measurements of Contact Pressure for Jointed Interfaces During Dynamic Loading Experiments," Cham, 2017: Springer International Publishing, in Dynamics of Coupled Structures, Volume 4, pp. 133-141. </ref><ref> M. Brake, C. Schwingshackl, and P. Reuß, "Observations of variability and repeatability in jointed structures," Mechanical Systems and Signal Processing, vol. 129, pp. 282-307, 2019.</ref><ref name= "FarField"> S. B. Cooper et al., "Effect of Far-Field Structure on Joint Properties," Cham, 2017: Springer International Publishing, in Dynamics of Coupled Structures, Volume 4, pp. 63-77. </ref><ref name = "InterfaceGeom"> T. Dossogne et al., "Experimental Assessment of the Influence of Interface Geometries on Structural Dynamic Response," Cham, 2017: Springer International Publishing, in Dynamics of Coupled Structures, Volume 4, pp. 255-261. </ref><ref>R. Lacayo et al., "Nonlinear modeling of structures with bolted joints: a comparison of two approaches based on a time-domain and frequency-domain solver," Mechanical Systems and Signal Processing, vol. 114, pp. 413-438, 2019. </ref>, the beam was made using stock material available in the USA; while not a drastic change in size, the beam needed to be redesigned with the new available dimensions.

			The geometry of the BRB started to be modified starting in 2016. The first modifications were of the interface geometry, where the flat lap joint was modified to have: Hertzian Contact, a Small Pad (equivalent to a standard washer), a Large Pad (equivalent to an oversized washer), and a Reverse Pad (where the oversized washer material was removed of the interface and the bolted connections)<ref name =" InterfaceGeom"/>. At the same time, the far-field effects were studied; the beam was modified to be longer (an additional 6" of material on each end), and removing material from the original length to create a spring-like structure<ref name= "FarField"/>. In 2017, the flat interface was then modified to have a curved geometry, simulating poor machining practice/ machine error<ref>I. Lawal, S. Shah, M. Gonzalez-Madrid, T. Hu, C W. Schwingshackl, and M. R. W. Brake, "The Effect of Non-Flat Interfaces on System Dynamics," IMAC XXXVI A Conference and Exposition on Structural Dynamics, Orlando, FL, February, 2018.</ref><ref>W. Chen, M. Jin, I G. Lawal, M. R. W. Brake, and H. Song, "Measurement of Slip and Separation in Jointed Structures with Non-Flat Interfaces," Mechanical Systems and Signal Processing, 134, pp 106325 (1-22), 2019.</ref>. In 2019, the beam was modified to have a 1" x 1/2" x 28" geometry (the reduction is parallel to the joint interface), to enable easier measurements using DIC<ref>M. Cenedese, M. Jin, G. Kosova, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, J. P. Noel, and S. Nagarajaiah, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part II Data Analysis," Tribomechadynamics 2019, Houston, TX, August, 2019.</ref><ref>D. Jana, W. Chen, A. Singh, M. Jin, G. Kosova, M. Cenedese, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, J. P. Noel, and S. Nagarajaiah, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part I Experimental Investigation," Tribomechadynamics 2019, Houston, TX, August 2019.</ref><ref>A. Singh, W. Chen, D. Jana, M. Jin, M. Cenedese, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, and J.-P. Noël, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part 1 Experimental Investigation," IMAC XXXVIII A Conference and Exposition on Structural Dynamics, Houston, TX, February, 2020.</ref><ref>G. Kosova, M. Jin, M. Cenedese, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, K. J. Moore, and J.-P. Noël, "Nonlinear System Identification of a Jointed Structure Using Full-Field Data: Part II Analysis," IMAC XXXVIII A Conference and Exposition on Structural Dynamics, Houston, TX, February, 2020.</ref><ref>M. Jin, G. Kosova, M. Cenedese, W. Chen, A. Singh, D. Jana, M. R. W. Brake, C. W. Schwingshackl, S. Nagarajaiah, K. J. Moore, and J.-P. Noel, "Nonlinear Identification of a Jointed Structure Using Full-Field Data Part II – Analysis," Mechanical Systems and Signal Processing, under review.</ref><ref>W. Chen, D. Jana, A. Singh, M. Jin, M. Cenedese, G. Kosova, M. R. W. Brake, C. W. Schwingshackl, S. Nagarajaiah, K. J. Moore, and J.-P. Noel, "Nonlinear Identification of a Jointed Structure Using Full-Field Data Part I – Experimental Investigation," Mechanical Systems and Signal Processing, under review.</ref>. Finally, one side of the beam was Additively Manufactured and shortened; this allowed the study of adding internal vibration absorbers and their effects on the response of the joint <ref> H. Shu, S. A. Smith, and M. R. W. Brake, "The Influence of Additively Manufactured Nonlinearities on the Dynamic Response of Assembled Structures," ASME Journal of Vibration and Acoustics, 142, pp 011019-1-9, 2020.</ref>.

	=== Main features ===		=== Main features ===
			The main features of this benchmark are:
			# Simple, easy to manufacture geometry
			# Easily modifiable to test various geometries
			# Only 1 location for nonlinear effects
			# Lap joints have strong nonlinear effects on the system's Transfer function, which is observable at low amplitudes <ref> M. W. Sracic, M. S. Allen, and H. Sumali, \Identifying the modal properties of nonlinear structures using measured free response time histories from a scanning
			laser doppler vibrometer," in 30th International Modal Analysis Conference(IMAC XXX), (Jacksonville, FL), February 2012.</ref>.

	=== Reasonable benchmark usage ===		=== Reasonable benchmark usage ===

MKuts: The New Benchmark commented

2021-09-28T11:34:00Z

The New Benchmark commented

← Older revision		Revision as of 07:34, 28 September 2021
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	=== Reasonable benchmark usage ===		=== Reasonable benchmark usage ===
	<!-- == The New Benchmark ==		<!--
			== The New Benchmark ==
	=== Description ===		=== Description ===

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	=== Reasonable benchmark usage ===		=== Reasonable benchmark usage ===

	== Referenses == ~~-->~~		-->
			== Referenses ==
	<references />		<references />

MKuts at 11:33, 28 September 2021

2021-09-28T11:33:04Z

← Older revision		Revision as of 07:33, 28 September 2021
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	=== Reasonable benchmark usage ===		=== Reasonable benchmark usage ===
	== The New Benchmark ==		<!-- == The New Benchmark ==
	=== Description ===		=== Description ===

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	== Referenses ==		== Referenses == -->
	<references />		<references />

MKuts: /* Description */

2021-09-28T11:30:57Z

Description

← Older revision		Revision as of 07:30, 28 September 2021
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	</div></div>		</div></div>

	<gallery heights=~~300px~~ widths=600px mode="packed">		<gallery heights=250px widths=600px mode="packed">
	File:S4BeamDraft.png\|Drawing of the S4-beam benchmark		File:S4BeamDraft.png\|Drawing of the S4-beam benchmark
	</gallery>		</gallery>

MKuts: /* Description */

2021-09-28T11:30:40Z

Description

← Older revision		Revision as of 07:30, 28 September 2021
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	</div></div>		</div></div>

	<gallery heights=~~200px~~ widths=~~400px~~ mode="packed">		<gallery heights=300px widths=600px mode="packed">
	File:S4BeamDraft.png\|Drawing of the S4-beam benchmark		File:S4BeamDraft.png\|Drawing of the S4-beam benchmark
	</gallery>		</gallery>

MKuts at 11:29, 28 September 2021

2021-09-28T11:29:58Z

← Older revision		Revision as of 07:29, 28 September 2021
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	<gallery heights=200px widths=400px mode="packed">		<gallery heights=200px widths=400px mode="packed">
	~~File:~~File:S4BeamDraft.png\|Drawing of the S4-beam benchmark		File:S4BeamDraft.png\|Drawing of the S4-beam benchmark
	</gallery>		</gallery>

← Older revision		Revision as of 09:05, 28 September 2021
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	=== Description ===		=== Description ===

	The Ampair 600 wind turbine was the first ~~true~~ benchmark system for the current generation of research challenges ~~as it~~ has been studied widely and shared amongst ~~a number of different~~ institutions. Unlike other proposed benchmark systems, it is not an academic system but rather ~~a real~~ application.		The Ampair 600 wind turbine was the first proper benchmark system for the current generation of research challenges. It has been studied widely and shared amongst several institutions. Unlike other proposed benchmark systems, it is not an academic system but rather an actual application.
	[[File:FullTurbine.png\|thumb\|The Ampair 6000 Wind Turbine]]		[[File:FullTurbine.png\|thumb\|The Ampair 6000 Wind Turbine]]
	The wind turbine, consists of three blades each connected to the central hub with three bolted joints near the root of the ~~blade. The~~ hub and generator housing ~~are also connected by a central bolt~~. The benchmark documentation on the website contains detailed instructions on how to assemble this ~~test bed~~ so that different research groups can obtain comparable results. This guide includes links to purchase any parts needed to construct the turbine and detailed instructions for assembly process including the hub potting and bolt torques. These instructions can be found on the [https://substructure.engr.wisc.edu/substwiki/index.php?title=Main_Page Dynamic Substructuring wiki].		The wind turbine consists of three blades, each connected to the central hub with three bolted joints near the blade's root. A central bolt also connects the hub and generator housing. The benchmark documentation on the website contains detailed instructions on how to assemble this testbed so that different research groups can obtain comparable results. This guide includes links to purchase any parts needed to construct the turbine and detailed instructions for the assembly process, including the hub potting and bolt torques. These instructions can be found on the [https://substructure.engr.wisc.edu/substwiki/index.php?title=Main_Page Dynamic Substructuring wiki].
	=== Variations ===		=== Variations ===
			None Found.
	===== Works on dynamic substructuring =====		===== Works on dynamic substructuring =====
	The wind turbine assembly and several of its subcomponents have been extensively tested and studied by several institutions. Sandia National Labs and the University of Wisconsin, Madison have performed roving hammer tests of the ~~full~~ system assembly and ~~the assembly~~ without the blades attached. Data sets from these tests can be found [http://substructure.engr.wisc.edu/substwiki/index.php/ Full_Turbine_Roving_Hammer_Test-UW_Madison here] and [http://substructure.engr.wisc.edu/substwiki/index.php/ No-blade_Turbine_Roving_Hammer_Test-UW_Madison here].		The wind turbine assembly and several of its subcomponents have been extensively tested and studied by several institutions. Sandia National Labs and the University of Wisconsin, Madison, have performed roving hammer tests of the whole system assembly and without the blades attached. Data sets from these tests can be found [http://substructure.engr.wisc.edu/substwiki/index.php/ Full_Turbine_Roving_Hammer_Test-UW_Madison here] and [http://substructure.engr.wisc.edu/substwiki/index.php/ No-blade_Turbine_Roving_Hammer_Test-UW_Madison here].

	Additional tests were performed on both a single-blade and hub assembly and on a three-blade and hub assembly. These tests were performed to develop a dynamic substructure model of the system. The results from these substructuring trials can be found in Rohe and Mayes<ref>D.P. Rohe, R.L. Mayes, Coupling of a bladed hub to the tower of the Ampair 600 wind turbine using the transmission simulator method, in 31st International Modal Analysis Conference (IMAC XXXI), Garden Grove, CA, 2013</ref> and Roettgen and Mayes<ref>D.R. Roettgen, R.L. Mayes, Ampair 600 wind turbine 3-bladed assembly substructuring using the transmission simulator method, in 33rd International Modal Analysis Conference (IMAC XXXIII), Orlando, FL, 2015</ref> . Rohe, Roettgen, ~~and~~ Allen and Mayes have performed several additional [http://substructure.engr.wisc.edu/substwiki/index.php/ Rotor_System_Tests_(Single_and_Three_Bladed_Assembly) tests] with data being organized and added to the wiki continuously.		Additional tests were performed on both a single-blade and hub assembly and a three-blade and hub assembly. These tests were performed to develop a dynamic substructure model of the system. The results from these substructuring trials can be found in Rohe and Mayes<ref>D.P. Rohe, R.L. Mayes, Coupling of a bladed hub to the tower of the Ampair 600 wind turbine using the transmission simulator method, in 31st International Modal Analysis Conference (IMAC XXXI), Garden Grove, CA, 2013</ref> and Roettgen and Mayes<ref>D.R. Roettgen, R.L. Mayes, Ampair 600 wind turbine 3-bladed assembly substructuring using the transmission simulator method, in 33rd International Modal Analysis Conference (IMAC XXXIII), Orlando, FL, 2015</ref>. Rohe, Roettgen, Allen, and Mayes have performed several additional [http://substructure.engr.wisc.edu/substwiki/index.php/ Rotor_System_Tests_(Single_and_Three_Bladed_Assembly) tests] with data being organized and added to the wiki continuously.

	Harvie and Avitabile in their work<ref>J. Harvie, P. Avitabile, Comparison of some wind turbine blade tests in various configurations, in 30th International Modal Analysis Conference (IMAC XXX), Jacksonville, FL, 2012</ref> studied the dynamic characteristics of six blades in ~~freefree~~, mass loaded, and clamped test conditions. Chalmers University of Technology completed dynamics testing on 12 different blades to gather variation data on the blade itself. Some information on these tests is available on the wiki and in Gibanica et al.<ref>M. Gibanica et al., Spread in modal data obtained from wind turbine blade testing, in 31st International Modal Analysis Conference (IMAC XXXI), Garden Grove, CA, 2013</ref> These studies provide a baseline of variability from structure to structure. ~~Similar blade testing was completed by the~~ University of Stuttgart. These experimental results were used to update a finite element model of the blade and are located in the [https://substructure.engr.wisc.edu/substwiki/index.php?title=University_of_Stuttgart Dynamic Substructuring Wiki] and detailed in Groß et al.<ref>J. Groß et al., Model updating of the Ampair Wind turbine substructures, in 32nd International Modal Analysis Conference (IMAC XXXII), Orlando, FL, 2014</ref> Several other institutions and groups have complete testing and dynamic substructuring on the ~~test bed~~, which is also documented on the Dynamic Substructuring Wiki.		Harvie and Avitabile in their work<ref>J. Harvie, P. Avitabile, Comparison of some wind turbine blade tests in various configurations, in 30th International Modal Analysis Conference (IMAC XXX), Jacksonville, FL, 2012</ref> studied the dynamic characteristics of six blades in free-free, mass loaded, and clamped test conditions. The Chalmers University of Technology completed dynamics testing on 12 different blades to gather variation data on the blade itself. Some information on these tests is available on the wiki and in Gibanica et al.<ref>M. Gibanica et al., Spread in modal data obtained from wind turbine blade testing, in 31st International Modal Analysis Conference (IMAC XXXI), Garden Grove, CA, 2013</ref> These studies provide a baseline of variability from structure to structure. The University of Stuttgart completed similar blade testing. These experimental results were used to update a finite element model of the blade and are located in the [https://substructure.engr.wisc.edu/substwiki/index.php?title=University_of_Stuttgart Dynamic Substructuring Wiki] and detailed in Groß et al.<ref>J. Groß et al., Model updating of the Ampair Wind turbine substructures, in 32nd International Modal Analysis Conference (IMAC XXXII), Orlando, FL, 2014</ref> Several other institutions and groups have complete testing and dynamic substructuring on the testbed, which is also documented on the Dynamic Substructuring Wiki.

	===== Nonlinear Identification =====		===== Nonlinear Identification =====
	There have been a few attempts to investigate the nonlinearity of the Ampair Wind Turbine substructure. In 2014, Mayes and Roettgen<ref name=":1">D.R. Roettgen, R.L. Mayes, Ampair 600 wind turbine 3-bladed assembly substructuring using the transmission simulator method, in 33rd International Modal Analysis Conference (IMAC XXXIII), Orlando, FL, 2015</ref> took high-level nonlinear hits for the three-bladed turbine assembly. The objective of these tests was to screen the system to look for any instances of nonlinearity.		There have been a few attempts to investigate the nonlinearity of the Ampair Wind Turbine substructure. In 2014, Mayes and Roettgen<ref name=":1">D.R. Roettgen, R.L. Mayes, Ampair 600 wind turbine 3-bladed assembly substructuring using the transmission simulator method, in 33rd International Modal Analysis Conference (IMAC XXXIII), Orlando, FL, 2015</ref> took high-level nonlinear hits for the three-bladed turbine assembly. The objective of these tests was to screen the system to look for any instances of nonlinearity.

	During ~~the~~ 2014, Sandia ~~Nonlinear Mechanics and Dynamics Summer~~ Research Institute, one team took the first steps to use an Iwan model to connect ~~the blades of~~ the wind turbine to the hub. That research used experimental data to fit a physical Iwan model for the same hardware used in Roettgen and Mayes<ref name=":1" />. The uncertainty of the four parameters used in the Iwan model is then investigated ~~and accounted for~~.		During 2014, Sandia's [[Research_Camps\|NOMAD]] Research Institute, one team took the first steps to use an Iwan model to connect the wind turbine's blades to the hub. That research used experimental data to fit a physical Iwan model for the same hardware used in Roettgen and Mayes<ref name=":1" />. The uncertainty of the four parameters used in the Iwan model was then investigated.

	=== Main features ===		=== Main features ===

	The main feature of the Ampair 600 Wind Turbine is that each substructure (e.g., the blades or the hub) is not a monolithic structure. The blades are composed of composite materials and foam, and the central hub is potted with epoxy amongst other materials. As a result, accurate modeling of the system requires material models that include viscous and plastic behavior. While some methods exist to characterize this system in linearized portions of its domains, it is a more complicated ~~system~~ to use as a benchmark than other systems.		The main feature of the Ampair 600 Wind Turbine is that each substructure (e.g., the blades or the hub) is not a monolithic structure. The blades are composed of composite materials and foam, and the central hub is potted with epoxy, amongst other materials. As a result, accurate modeling of the system requires material models that include viscous and plastic behavior. While some methods exist to characterize this system in linearized portions of its domains, it is more complicated to use as a benchmark than other systems.

	Another feature of the Ampair 600 Wind Turbine is that ~~due to the construction method,~~ the measurement of joint properties ~~exhibit~~ a higher degree of variability than observed in other benchmark systems.		Another feature of the Ampair 600 Wind Turbine is that the measurement of joint properties exhibits a higher degree of variability than observed in other benchmark systems due to the construction method.
	=== Reasonable benchmark usage ===		=== Reasonable benchmark usage ===
	There has been a large amount of linear testing and research completed with the Ampair ~~test bed~~. Additional testing is still ongoing by the Dynamic Substructuring Focus Group ~~and is continuously uploaded to the substructuring wiki~~. Researchers have only ~~just~~ begun to investigate the nonlinear characteristics of the Ampair wind turbine, many of which may be driven by the joints. Preliminary experiments have shown that the ~~test bed~~ is suitable for investigation and research in the area of joint dynamics. Further, a large amount of experimental data in addition to high fidelity numerical models are available from the Dynamic Substructuring wiki. This wiki has been shown to facilitate the level of collaboration necessary for a round-robin study of a benchmark system. Even if the Ampair 600 Wind Turbine is not used as a benchmark system, lessons can be learned from the effectiveness of the wiki in terms of sharing information and promoting collaboration.		There has been a large amount of linear testing and research completed with the Ampair testbed. Additional testing is still ongoing by the Dynamic Substructuring Focus Group. Researchers have only begun to investigate the nonlinear characteristics of the Ampair wind turbine, many of which may be driven by the joints. Preliminary experiments have shown that the testbed is suitable for investigation and research in the area of joint dynamics. Further, a large amount of experimental data in addition to high fidelity numerical models are available from the Dynamic Substructuring wiki. This wiki has been shown to facilitate the level of collaboration necessary for a round-robin study of a benchmark system. Even if the Ampair 600 Wind Turbine is not used as a benchmark system, lessons can be learned from the effectiveness of the wiki in terms of sharing information and promoting collaboration.

	== The S4-Beam Beams ==		== The S4-Beam Beams ==