Benchmarks: Difference between revisions
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== Referenses == | == Referenses == | ||
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<ref name = "gaul87"> 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 </ref> | <ref name = "gaul87"> 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 </ref> | ||
Revision as of 13:20, 28 June 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 consist of two massive parts, connected to each other by the single lap joint, one of which is designed to have an elastic element in foundation of connection interface.
The resonator is designed in a way, that it has relatively low natural frequency, corresponds for the tangential movement in the joint. It allows to achieve a quite heavy dynamic tangential loadings by exciting the system around an axial resonance frequency.
The original resonator was developed by professor L. Gaul research group and was made from round steel stock. This resonator is investigated in Gaul and Bohlen (1987), Gaul et al. (1994), Lenz and Gaul (1995) and Gaul and Lenz (1997).
Variations
There are two similar systems developed at the University of Erlangen–Nürnberg. The first one is a similar to 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, a mechanical post-processing or rejuvenation of the contact interface is possible, and an accessibility for microscopic surface measurements is given. The detailed investigtion of these systems given in Süß and Willner (2012), Süß and Willner (2015) and Armand et al. (2018).
Anouther variation of such benchmark can be considered a dumbell oscilator investigated in Segelman et al. (2009). 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
The Ampair 600 Wind Turbine
The Brake-Reuß Beams
The New Benchmark
Referenses
[8] </references>
- ↑ 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 microslip 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.J. Segalman et al., Handbook on dynamics of jointed structures. Technical Report SAND2009-4164, Sandia National Laboratories, Albuquerque, NM (2009)
- ↑ 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 multiharmonic 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)