Benchmarks: Difference between revisions
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== The S4-Beam Beams == | == The S4-Beam Beams == | ||
=== Description === | === Description === | ||
This test benchmark was developed in [[Brigham Young University|group]] lead by Professor Matthew S. Allen. | |||
<div class="toccolours mw-collapsible mw-collapsed" style="width:410px; height=200; overflow:auto;"> | The S4-beam benchmark consists of two C-shaped beams manufactured with Stainless Steel type ANSI 304. In work Singh et al.<ref name=":0">A. Singh, M. Scapolan, Y. Saito, M. S. Allen, D. Roettgen, B. Pacini, and R. J. Kuether, Experimental characterization of a new benchmark structure for prediction of damping nonlinearity. In ''Nonlinear Dynamics, Volume 1'' (pp. 57-78). Springer, Cham. (2019)</ref>, where this benchmark was originally presented, two pair of beams were made: one pair with convex interface with a center to edge drop of 0.005’’ to 0.008’’, and one pair with flat interface. That allows to investigate four different types of the contact: curved-curved, curved-flat, flat-flat and curved-curved with SS Washer. All contact surfaces were polished to a minimum surface finish of Ra = 8. | ||
S4-beam was designed to have simpler interfaces, than BRB, but still allows investigating the joints influence on the nonlinear stiffness and damping. Consisted of two C-shaped beams, S4-beam is designed to model the nonlinear effects of joint bending and shearing in bolted structures.<div class="toccolours mw-collapsible mw-collapsed" style="width:410px; height=200; overflow:auto;"> | |||
<div style="font-weight:bold;line-height:1.6;">Cut beam's 3D model</div> | <div style="font-weight:bold;line-height:1.6;">Cut beam's 3D model</div> | ||
<div class="mw-collapsible-content"> | <div class="mw-collapsible-content"> | ||
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=== Variations === | === Variations === | ||
Variant of this test benchmark are dedicated to investigating of: | |||
# Different types of contact geometry | |||
# Different types of beams materials | |||
# Different types of the excitation | |||
# Different types of contact surface machining | |||
# Different contact pressure | |||
In the original work of Singh et al.<ref name=":0" /> two pairs of beams were made to investigate different types of contact geometry: one pair with convex interface with a center to edge drop of 0.005 <nowiki>''</nowiki> to 0.008 <nowiki>''</nowiki>, and one pair with the flat interface. Further, in work Wall, Allen and Kuether<ref>M. Wall, M. S. Allen, and R. J. Kuether, Observations of modal coupling due to bolted joints in an experimental benchmark structure. ''Mechanical Systems and Signal Processing'', ''162'', 107968. (2022)</ref> the identical set of 4340 stainless steel beams with a small radius applied to the edge of the contact interface, and different manufacturing deviations of contact surfaces from the nominal geometry were investigated. | |||
Another variation of this benchmark was made and investigated in the work Brink et al.<ref>A. R. Brink, R. J. Kuether, M. D. Fronk, B. L. Witt, and B. L. Nation. Contact stress and linearized modal predictions of as-built preloaded assembly. ''Journal of Vibration and Acoustics'', ''142''(5), 051106. (2020)</ref> At this paper the contact of nominally flat surfaces was observed, so the different contact surface characteristics were obtained. | |||
Also, there are several works, that used this benchmark system for computational purposes, such as Wall, Allen and Zare<ref>M. Wall, M. S. Allen, and I. Zare. Predicting S4 beam joint nonlinearity using quasi-static modal analysis. In ''Nonlinear Structures and Systems, Volume 1'' (pp. 39-51). Springer, Cham. (2020)</ref>, Jewell et al.<ref>Jewell, E., Allen, M. S., Zare, I., & Wall, M. (2020). Application of quasi-static modal analysis to a finite element model and experimental correlation. ''Journal of Sound and Vibration'', ''479'', 115376.</ref>, Witteveen and Koller<ref>W. Witteveen, and L. Koller. Hyper-Reduction for Simple Small Sliding Contact and Friction Force Laws - Tribomechadynamics 2021, (2021)</ref>. | |||
=== Main features === | === Main features === | ||
There are two main features of this test benchmark, which distinguish it from others: | |||
# It provides simple contact interface with only one bolt on each contact area | |||
# It provides several types of nonlinearity | |||
# It has pretty close two first mode, which leads to the mode coupling during vibrations. | |||
=== Reasonable benchmark usage === | === Reasonable benchmark usage === | ||
== The Brake-Reuß Beams == | == The Brake-Reuß Beams == | ||
Revision as of 13:23, 27 September 2021
One of the major aims of the committee is promoting the development and improvement of the technics of measurement and modelling of jointed structures behaviour, which often is nonlinear due to its intrinsic structure. The benchmark systems are aimed to help researchers to test their developed technics of jointed structure behaviour measurement and prediction. In other words – benchmarks serve as a reference system for verification. The benchmark system must have the following qualities:
- Well-controlled and understood boundary conditions to avoid uncertainties during experiment and modelling;
- Simple experimental setup to be easily repeatable and commonly used.
In this section several benchmarks, including its variations, pretended to be such reference systems, are described.
The Gaul Resonator
Description
The Gaul resonator consists of two massive parts, connected to each other by the single lap joint, one of which is designed to have an elastic element in the foundation of the connection interface.
The resonator is designed in a way, that has a relatively low natural frequency, corresponds to the tangential movement in the joint. It allows achieving quite heavy dynamic tangential loadings by exciting the system around an axial resonance frequency.
The original resonator was developed by professor L. Gaul's research group and was made from round steel stock. This resonator is investigated by Gaul and Bohlen [1], Gaul et al. [2], Lenz and Gaul [3], and Gaul and Lenz [4].
Variations
There are two similar systems developed at the University of Erlangen–Nürnberg. The first one is similar to the original resonator. The second one is an improved version made of flat stock material and a different orientation of the lap joint. This has the advantages that sensors can be attached in an easier manner, mechanical post-processing or rejuvenation of the contact interface is possible, and accessibility for microscopic surface measurements is given. The detailed investigation of these systems given by Süß and Willner[5][6], and Armand et al.[7].
Another variation of such benchmark can be considered a dumbbell oscillator investigated by Segelman[8]. This oscillator consists of two rigid steel cylindrical parts, which represent two masses, connected by a lap joint.
Main features
The main features of the Gaul Resonator -like systems are caused by its massive structure:
- Insensibility to the way/place sensor is attached and load is applied
- Better controllability of the boundary conditions
- Ability to store a large amount of energy for extensive ring-down testing
- Can be accurately simulated with a low-order model, which provides high performance of simulations
Reasonable benchmark usage
In spite of being a very academic structure, this system is an ideal benchmark for measuring the transfer behavior of a bolted lap joint and also delivers the opportunity to perform hysteresis measurements, which establishes a bridge between the two round-robin challenges.
The Cut Beam Benchmark
Description
The beam is built up with three parts linked by two planar joints. Planar joints assembled by applying normal force, which is applied using screw clamp. Furter, assembled beam clamped to the ground by bolted joints. The benchmark system should be assembled that way, to remain in contact due to the normal pre-load N and the friction between the counter-parts.
The purpose of this benchmark is to measure the damping induced by partial slip and friction in a planar joint.
This benchmark was originally made and investigated by Jean-Luc Dion, Gael Chevallier, and Nicolas Peyret. The design of this benchmark is based on and justified in Peyret et al[9][10]. Detailed description of the experiment and main results are presented in Peyret, Dion and Chevallier[11] and Dion, Chevallier, and Peyret[12].
Variations
Currently, there is not known about any variation of this benchmark.
Main features
Main feature of this benchmark is that it allows measuring damping in the pure interface, avoiding the influence of bolts, which ordinary presents in other academic benchmarks.
The benchmark system was designed so that to have nil bending moment over non-zero length. Also, particular attention was given to obtaining the highest frequency for the second bending mode in order to avoid coupling between the first two modes.
Due to that this work requires an accurate method of measurement of nonlinear damping, in the original article the stopped-sine excitation was used as it allows obtaining a single frequency response and studying nonlinear modes with frequency and natural magnitude modulations without other mode couplings.
Reasonable benchmark usage
The shape of the designed benchmark can be used to define contact damping of specimens of several materials, roughnesses, and flatnesses, with or without coating, in order to obtain a library of behaviors for use in the design of jointed structures.
The Ampair 600 Wind Turbine
Description
Variations
Main features
Reasonable benchmark usage
The S4-Beam Beams
Description
This test benchmark was developed in group lead by Professor Matthew S. Allen.
The S4-beam benchmark consists of two C-shaped beams manufactured with Stainless Steel type ANSI 304. In work Singh et al.[13], where this benchmark was originally presented, two pair of beams were made: one pair with convex interface with a center to edge drop of 0.005’’ to 0.008’’, and one pair with flat interface. That allows to investigate four different types of the contact: curved-curved, curved-flat, flat-flat and curved-curved with SS Washer. All contact surfaces were polished to a minimum surface finish of Ra = 8.
S4-beam was designed to have simpler interfaces, than BRB, but still allows investigating the joints influence on the nonlinear stiffness and damping. Consisted of two C-shaped beams, S4-beam is designed to model the nonlinear effects of joint bending and shearing in bolted structures.
Variations
Variant of this test benchmark are dedicated to investigating of:
- Different types of contact geometry
- Different types of beams materials
- Different types of the excitation
- Different types of contact surface machining
- Different contact pressure
In the original work of Singh et al.[13] two pairs of beams were made to investigate different types of contact geometry: one pair with convex interface with a center to edge drop of 0.005 '' to 0.008 '', and one pair with the flat interface. Further, in work Wall, Allen and Kuether[14] the identical set of 4340 stainless steel beams with a small radius applied to the edge of the contact interface, and different manufacturing deviations of contact surfaces from the nominal geometry were investigated.
Another variation of this benchmark was made and investigated in the work Brink et al.[15] At this paper the contact of nominally flat surfaces was observed, so the different contact surface characteristics were obtained.
Also, there are several works, that used this benchmark system for computational purposes, such as Wall, Allen and Zare[16], Jewell et al.[17], Witteveen and Koller[18].
Main features
There are two main features of this test benchmark, which distinguish it from others:
- It provides simple contact interface with only one bolt on each contact area
- It provides several types of nonlinearity
- It has pretty close two first mode, which leads to the mode coupling during vibrations.
Reasonable benchmark usage
The Brake-Reuß Beams
Description
Variations
Main features
Reasonable benchmark usage
The New Benchmark
Description
Variations
Main features
Reasonable benchmark usage
Referenses
- ↑ L. Gaul, S. Bohlen, Identification of nonlinear structural joint models and implementation in discretized structure models, in ASME Design Technology Conference – 11th Biennial Conference on Mechanical Vibration and Noise, Boston, MA, 1987
- ↑ L. Gaul et al., Nonlinear vibration damping of structures with bolted joints, in 12th International Modal Analysis Conference (IMAC XII), Honolulu, HI, 1994
- ↑ J. Lenz, L. Gaul, The influence of micro-slip on the dynamic behavior of bolted joints, in 13th International Modal Analysis Conference (IMAC XIII), Nashville, TN, 1995
- ↑ L. Gaul, J. Lenz, Nonlinear dynamics of structures assembled by bolted joints. Acta Mechanica. 169-182 (1997)
- ↑ D. Süß, K. Willner, Multiharmonic balance analysis of a jointed friction oscillator, in ECCOMAS 2012 – European Congress on Computational Methods in Applied Sciences and Engineering, Vienna, 2012
- ↑ D. Süß, K. Willner, Investigation of a jointed friction oscillator using the multi-harmonic balance method. Mech. Syst. Signal Process. 52–53, 73–87 (2015)
- ↑ J. Armand et al., On the effects of roughness on the nonlinear dynamics of a bolted joint: A multiscale analysis.European Journal of Mechanics. 44-57 (2018)
- ↑ D.J. Segalman et al., Handbook on dynamics of jointed structures. Technical Report SAND2009-4164, Sandia National Laboratories, Albuquerque, NM (2009)
- ↑ N. Peyret et al., Non linear dynamic behavior modelling of a planar friction interface in a structure assembly, in ASME International Design Engineering Technical Conferences IDETC/CIE, San Diego, CA, 2009
- ↑ N. Peyret et al., Micro slip induced damping in planar contact under constant and uniform normal stress. Int. J. Appl. Mech. 2, 281–304 (2010)
- ↑ N. Peyret, J. L. Dion, and G. Chevallier. A framework for backbone experimental tracking: Piezoelectric actuators, stop-sine signal and Kalman filtering. Mechanical Systems and Signal Processing, 78, 28-42. (2016)
- ↑ J. L. Dion, G. Chevallier, and N. Peyret. The Cut Beam Benchmark System: Developing Measurement Techniques for Nonlinear Damping and Stiffness in Frictional Interfaces. In The Mechanics of Jointed Structures (pp. 73-89). Springer, Cham., 2018
- ↑ 13.0 13.1 A. Singh, M. Scapolan, Y. Saito, M. S. Allen, D. Roettgen, B. Pacini, and R. J. Kuether, Experimental characterization of a new benchmark structure for prediction of damping nonlinearity. In Nonlinear Dynamics, Volume 1 (pp. 57-78). Springer, Cham. (2019)
- ↑ M. Wall, M. S. Allen, and R. J. Kuether, Observations of modal coupling due to bolted joints in an experimental benchmark structure. Mechanical Systems and Signal Processing, 162, 107968. (2022)
- ↑ A. R. Brink, R. J. Kuether, M. D. Fronk, B. L. Witt, and B. L. Nation. Contact stress and linearized modal predictions of as-built preloaded assembly. Journal of Vibration and Acoustics, 142(5), 051106. (2020)
- ↑ M. Wall, M. S. Allen, and I. Zare. Predicting S4 beam joint nonlinearity using quasi-static modal analysis. In Nonlinear Structures and Systems, Volume 1 (pp. 39-51). Springer, Cham. (2020)
- ↑ Jewell, E., Allen, M. S., Zare, I., & Wall, M. (2020). Application of quasi-static modal analysis to a finite element model and experimental correlation. Journal of Sound and Vibration, 479, 115376.
- ↑ W. Witteveen, and L. Koller. Hyper-Reduction for Simple Small Sliding Contact and Friction Force Laws - Tribomechadynamics 2021, (2021)