Robust optimization and uncertainty quantification in the nonlinear mechanics of an elevator brake system

Wolszczak, Piotr; Lonkwic, P.; Cunha, Americo; Litak, Grzegorz; Molski, Szymon

doi:10.1007/s11012-019-00992-7

Cited by 16 publications

(12 citation statements)

References 19 publications

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“…The pursued value gets stabilized and is treated as an expected value, and the analysis is considered to be concurrent. A loose criteria of convergence (i.e., high tolerance of more than 10%) may lead to imprecise results, while a too low tolerance of convergence might cause an unjustified increase of "computation costs" (computation time, equipment requirements) needed to obtain the results to an "excessive" accuracy degree that does not add any significant changes to the value and the very analysis of results [12].…”

Section: Digitizationmentioning

confidence: 99%

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Application of Stray Magnetic Field for Monitoring the Wear Degree in Steel Components of the Lift Guide Rail System

Lonkwic

Krakowski

Ruta

2020

Metals

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This paper presents the results of forced wear simulation of the friction lift guide rails. The forced wear in the case discussed is an effect of plastic strain of the guide rail surface due to emergency braking of the lift. For the purpose of qualitative and quantitative assessment of wear, the authors applied the numerical simulation of a stray magnetic field. Application of this method allowed evaluating the degree of wear based on the stray field changes. Application of this simulation method allowed obtaining satisfactory results of qualitative and quantitative assessment of the guide rail wear. The intention of this paper was to prove that the permanent magnetic field and the stray field can be applied for the efficient detection of the steel guide rail damages and to verify the possibility of making the quantitative assessment related to the guide rail wear degree versus the personal lift service life.

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Section: Digitizationmentioning

confidence: 99%

“…In publications [12][13][14], the authors presented the results of their own mathematical and statistical analysis of results obtained during the emergency braking of a lift, including time-lag values and braking distance having an impact on the durability and life of the lift guide rails.…”

Section: Introductionmentioning

confidence: 99%

Application of Stray Magnetic Field for Monitoring the Wear Degree in Steel Components of the Lift Guide Rail System

Lonkwic

Krakowski

Ruta

2020

Metals

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“…In many practical situations the real stochastic model of noise is unknown. In that case, the maximum entropy principle is helpful in creating realistic models [37,40].…”

Section: Stochastic Model Of Noisementioning

confidence: 99%

Inspection of ratcheting models for pathological error sensitivity and overparametrization

Kaygorodtseva¹,

Shutov²

2021

Preprint

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Accurate analysis of plastic strain accumulation under stress-controlled cyclic loading is vital for numerous engineering applications. Typically, models of plastic ratcheting are calibrated against available experimental data. Since actual experiments are not exactly accurate, one should check the identification protocols for pathological dependencies on experimental errors. In this paper, a step-by-step algorithm is presented to estimate the sensitivities of identified material parameters. As a part of the sensitivity analysis method, a new mechanics-based metric in the space of material parameters is proposed especially for ratchetingrelated applications. The sensitivity of material parameters to experimental errors is estimated, based on this metric. For demonstration purposes, the accumulation of irreversible strain in the titanium alloy VT6 (Russian analog of Ti-6Al-4V) is analysed. Three types of phenomenological models of plastic ratcheting are considered. They are the Armstrong-Frederick model as well as the first and the second Ohno-Wang models. Based on real data, a new rule of isotropic hardening is proposed for greater accuracy of simulation. The ability of the sensitivity analysis to determine reliable and unreliable parameters is demonstrated. The plausibility of the new method is checked by alternative approaches, like the consideration of correlation matrices and validation of identified parameters on "unseen" data. A relation between pathological error sensitivity and overparametrization is established.

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“…Lonkwic et al (2016a) studied the impact of variable operating conditions on the value of braking process delay for progressive gears. Wolszczak et al (2019) studied the nonlinear mechanics of an elevator brake system subjected to uncertainties. Lonkwic et al (2016b) conducted independent tests on the impact of progressive gears in short distance transportation devices due to geometry.…”

Section: Introductionmentioning

confidence: 99%

Development of prototype machine brake and car safety gear testers for traction lift systems

Lam

Kong

et al. 2021

HKIE Transactions

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Machine brakes and safety gears of traction lifts are two critical components of the biggest safety concerns, as the main braking system and redundant fail-safe mechanism respectively stop and hold lift cars from unintended car movement, overspeed or under a free-fall condition during emergency. There are challenges of routine maintenance on how to continually verify the effectiveness of them to mitigate risk potentials of equipment failure. This pilot study intends to design, implement and test low-cost, non-intrusive and on-line prototype testers with the aid of sensors for real-time monitoring of critical parameters of these safety devices. Critical parameters that are measurable include real-time variations of brake lining temperature, brake solenoid current, vibrational patterns of brake arms and lift car, position of lift car, and the actuating status of safety gears. Critical parameters after processing include a newly defined energy of brake arm operation and estimated deceleration rate of a fully loaded car by safety gears operation on an unloaded car. Early signs of abnormalities of these two safety devices can be detected before they fail. Additionally, the prototype testers can facilitate more frequent unloaded full-speed testing of safety gears to verify the effectiveness. The proof-of-concept prototype could be a quick monitoring alternative to existing and new traction lift systems.

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Robust optimization and uncertainty quantification in the nonlinear mechanics of an elevator brake system

Cited by 16 publications

References 19 publications

Application of Stray Magnetic Field for Monitoring the Wear Degree in Steel Components of the Lift Guide Rail System

Application of Stray Magnetic Field for Monitoring the Wear Degree in Steel Components of the Lift Guide Rail System

Inspection of ratcheting models for pathological error sensitivity and overparametrization

Development of prototype machine brake and car safety gear testers for traction lift systems

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