Benchmarks: Difference between revisions

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=== Variations ===
=== Variations ===
[[File:Suss Willner(1).png|thumb|Round resonator used in work]]
 
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. These variations allow sensors to be more easily attached, mechanical post-processing/rejuvenating the contact interface, and accessibility to the surface for microscopic measurements. The detailed investigation of these systems given by Süß and Willner<ref name = "suss12"> 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 </ref><ref name = "sess15"> 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)</ref>, and Armand et al.<ref name = "armand18"> 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) </ref>.
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. These variations allow sensors to be more easily attached, mechanical post-processing/rejuvenating the contact interface, and accessibility to the surface for microscopic measurements. The detailed investigation of these systems given by Süß and Willner<ref name = "suss12"> 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 </ref><ref name = "sess15"> 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)</ref>, and Armand et al.<ref name = "armand18"> 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) </ref>.


Another benchmark variation is the dumbbell oscillator investigated by Segelman<ref name = "segalman09">D.J. Segalman et al., Handbook on dynamics of jointed structures. Technical Report SAND2009-4164, Sandia National Laboratories, Albuquerque, NM (2009) </ref>. This oscillator consists of two rigid steel cylindrical parts, representing two masses connected by a lap joint.
Another benchmark variation is the dumbbell oscillator investigated by Segelman<ref name = "segalman09">D.J. Segalman et al., Handbook on dynamics of jointed structures. Technical Report SAND2009-4164, Sandia National Laboratories, Albuquerque, NM (2009) </ref>. This oscillator consists of two rigid steel cylindrical parts, representing two masses connected by a lap joint.
<gallery heights=250px widths=300px>
File:Suss Willner(1).png|Round resonator<ref name="suss12" />
File:Suss Willner(2).png|Rectangle resonator<ref name="suss12" />
File:Dumbell oscillator.png|Dumbell oscillator<ref name = "segalman09" />
</gallery>


=== Main features ===
=== Main features ===
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* Insensibility to the way/place sensors are attached and load is applied  
* Insensibility to the way/place sensors are attached and load is applied  
* [[File:Suss Willner(2).png|thumb|Rectangle resonator used in work]]Better controllability of the boundary conditions
* Better controllability of the boundary conditions
* Ability to store a large amount of energy for extensive ring-down testing
* 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
* Can be accurately simulated with a low-order model, which provides high performance of simulations

Revision as of 03:09, 28 September 2021

One of the committee's primary aims is to promote the development and improvement of measurement techniques and model jointed structures' behavior. The behaviors are often nonlinear due to the intrinsicality of the structures. The benchmark systems aim to help researchers test their developed techniques to measure and predict the behaviors of reference systems. The benchmark system must have the following qualities:

  • Well-controlled and understood boundary conditions to avoid uncertainties during experiment and modeling;
  • Simple experimental setup to be easily repeatable and commonly used;
  • Simple to build.

Several benchmarks, including variations, are described in this section.

The Gaul Resonator

Description

The Gaul resonator consists of two massive parts, connected 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 to have a relatively low natural frequency, which corresponds to the joint's tangential movement. By exciting the resonator around an axial resonant frequency, high tangential loads are achieved.

Experimental setup with Gaul Resonator from original work

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].

Round resonator's 3D model

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. These variations allow sensors to be more easily attached, mechanical post-processing/rejuvenating the contact interface, and accessibility to the surface for microscopic measurements. The detailed investigation of these systems given by Süß and Willner[5][6], and Armand et al.[7].

Another benchmark variation is the dumbbell oscillator investigated by Segelman[8]. This oscillator consists of two rigid steel cylindrical parts, representing two masses connected by a lap joint.

Main features

The main features of the Gaul Resonator are:

  • Insensibility to the way/place sensors are 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

Despite being very academic structures, these systems are ideal benchmarks for measuring a bolted lap joints transfer behavior and allows the measurement of hysteresis, which creates a bridge between the two round-robin challenges.

The Cut Beam Benchmark

Description

Scheme of the experimental setup used in Dion, Chevallier, and Peyret.

The beam contains three parts linked by two planar joints. Planar joints are assembled by applying normal force via a screw clamp, and the system is clamped to the ground by bolted joints. The benchmark system is assembled such that the normal preload and friction keep the system assembled.

The benchmark allows the measurement of damping induced by partial slip and friction in a planar joint.

This benchmark was developed 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]. Peyret, Dion and Chevallier[11] and Dion, Chevallier, and Peyret[12] present the experiments and results on this structure.

Cut beam's 3D model

Variations

Currently, there are no known variations of this benchmark.

Main features

The main feature of this benchmark is that it allows for measuring damping in just the interface without the influence of bolts. The benchmark system was designed so that to have nil bending moment over non-zero length. Also, the system was designed to avoid the coupling of the first two modes. Due to these designs, these structures require an accurate method of measurement of nonlinear damping. The original article used the stopped-sine excitation to obtain a single frequency response and study nonlinear modes with frequency and natural magnitude modulations without other mode couplings.

Reasonable benchmark usage

The benchmark design can be used to define contact damping of specimens of several materials, roughnesses, and flatnesses, with or without coating, 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 stainless steel C-shaped beams. In Singh et al.[13], the benchmark is first introduced with two variations. One variation has a convex interface with a center to edge drop of 0.005" to 0.008" and one variation with a flat interface. These variations allow the investigation of four different contacts: curved-curved, curved-flat, flat-flat, and curved-curved with washers. 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.

Cut beam's 3D model

Variations

Variants of this test benchmark are used to investigate:

  1. Different types of contact geometry
  2. Different types of beams materials
  3. Different types of the excitation
  4. Different types of contact surface machining
  5. 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, Wall, Allen, and Kuether[14] modified the beams to have fillets on the edge of the contact interface, and other nominal geometries were investigated. Brink et al.[15] investigated the nominally flat surface variation of this structure.

Also, several works used this benchmark system for computational purposes, such as Wall, Allen, and Zare[16], Jewell et al.[17], Witteveen and Koller[18].

Main features

The main features of this test benchmark, which distinguish it from others:

  1. It provides a simple contact interface with only one bolt on each contact area;
  2. It provides several types of nonlinearity;
  3. It has two close fundamental modes, which lead to modal 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

  1. 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
  2. L. Gaul et al., Nonlinear vibration damping of structures with bolted joints, in 12th International Modal Analysis Conference (IMAC XII), Honolulu, HI, 1994
  3. 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
  4. L. Gaul, J. Lenz, Nonlinear dynamics of structures assembled by bolted joints. Acta Mechanica. 169-182 (1997)
  5. 5.0 5.1 5.2 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
  6. 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)
  7. 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)
  8. 8.0 8.1 D.J. Segalman et al., Handbook on dynamics of jointed structures. Technical Report SAND2009-4164, Sandia National Laboratories, Albuquerque, NM (2009)
  9. N. Peyret et al., Nonlinear dynamic behavior modeling of a planar friction interface in a structure assembly, in ASME International Design Engineering Technical Conferences IDETC/CIE, San Diego, CA, 2009
  10. 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)
  11. 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)
  12. 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. 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)
  14. 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)
  15. 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)
  16. 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)
  17. 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.
  18. W. Witteveen, and L. Koller. Hyper-Reduction for Simple Small Sliding Contact and Friction Force Laws - Tribomechadynamics 2021, (2021)