Article
Engineering, Aerospace
Troy Krizak, Eric Kurstak, Kiran D'Souza
Summary: This study demonstrates how two linear models can determine bounds for the nonlinear response of a bladed disk system with under-platform dampers. The ROM methods used in this work, the component mode mistuning method and parametric ROM method, are able to model small mistuning and rotational speed effects. The effectiveness of these models in predicting the bounds is evaluated by comparing the blade tip amplitudes from the models with experimental data.
Article
Engineering, Mechanical
S. Mehrdad Pourkiaee, Teresa Berruti, Stefano Zucca, Geoffrey Neuville
Summary: This paper investigates the mistuned forced responses of an integrally bladed disk with underplatform dampers, providing an experimental benchmark and a numerical model. Experimental results show that the proposed model accurately predicts the modulation effects of linear and nonlinear mistuned frequency response functions.
JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME
(2021)
Article
Construction & Building Technology
Ya-Jie Wu, Qi-Fang Xie, He-Shou Lin, Li -Peng Zhang, Hui-Feng Yang
Summary: This paper proposes variable friction timber dampers (VFTDs) and investigates their seismic behavior, lateral performance, and dynamic response in heavy timber frames. Experimental and numerical results demonstrate that VFTDs have high lateral load-resisting capacity and energy dissipation capacity, leading to significant reductions in peak drift and acceleration of timber frames.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Engineering, Mechanical
Muzio M. Gola
Summary: This paper presents a general geometric theory for the in-plane motion of underplatform dampers as a function of blade neck deflection and the resulting platform kinematics. It introduces the concept of equivalent virtual parallel geometry and develops equations for both In-Phase and Out-of-Phase blade vibrations. The paper also proposes a piecewise linear algorithm to pre-compute a cycle and introduces the concept of force Base-Cycle and moment Base-Cycle for the damper-platform system.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Chemistry, Analytical
Luigi Carassale, Elena Rizzetto
Summary: Bladed disks are key components of turbomachines, and the behavior of mistuned disks is important for system identification. This study describes the implementation of a test rig to investigate mistuned disk behavior and develop data processing techniques. The experimental setup involves fixing the disk while rotating the excitation part, and comparing three alternative techniques to estimate the frequency-response function of the disk.
Article
Engineering, Aerospace
Yanan Wu, Haijun Xuan, Changyao Wu, Dong Mi, Mingmin Qu, Tao Jin
Summary: This study investigated the effect of underplatform dampers (UPDs) on the forced torsional vibration response of turbine blades within a multi-blade system. Pre-stressed finite element modal analysis and the harmonic balance method were used to calculate the vibration responses. The experiments on a rotating multi-blade system showed that UPDs could effectively reduce blade torsional vibration but excessive force could lead to large vibration peaks.
Article
Engineering, Mechanical
Samuel Quaegebeur, Benjamin Chouvion, Fabrice Thouverez
Summary: In the process of designing turbo-engines, adding various underplatform dampers to reduce vibratory energy is a possible solution. This paper introduces a new method to assess the performance of dampers in cyclic symmetric structures and investigates the effectiveness of intentionally mistuning underplatform dampers.
JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME
(2021)
Article
Engineering, Mechanical
Jie Yuan, Alfredo Fantetti, Enora Denimal, Shubham Bhatnagar, Luca Pesaresi, Christoph Schwingshackl, Loic Salles
Summary: This study aims to obtain uncertainty bands in the dynamic response of turbine blades equipped with dampers by introducing the variability observed in interfacial contact parameters. Sobol indices analysis is used to quantify the influence of contact parameters on the variation in the nonlinear dynamic response.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Engineering, Aerospace
Eric Kurstak, Kiran D'Souza
Summary: This work involves an experimental and computational investigation of a rotating bladed disk excited with air jets. It computes mistuning and damping values of the system using experimental results, and uses a parametric reduced order model to adjust the system stiffness based on rotational speed. By coupling component mode mistuning with the PROM, a mistuned model capable of capturing the mistuned system dynamics is created. Computational values for blade frequency, amplitude, and damping are compared with experimental results to demonstrate the effectiveness of the computational model in characterizing a rotating bladed disk.
Article
Engineering, Civil
Jingwei Gao, Chun-Lin Wang, Bin Zeng, Tianyi Qiu
Summary: This paper proposes a novel sleeved member with additional friction dampers (FSM) to enhance stability and energy dissipation in compression members of space structures. The FSM consists of an inner core, an outer sleeve, and friction dampers using composite friction materials. Cyclic compression-unloading tests were conducted to compare the FSM with an ordinary assembled sleeve member (ASM). The results showed that the FSM exhibited comparable lateral-constraint capacity, greater resistance, and greater energy dissipation capacity under tiny axial displacement.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Mechanical
Javier Gonzalez-Monge, Salvador Rodriguez-Blanco, Carlos Martel
Summary: Flutter and forced response often occur simultaneously in turbomachinery systems. Their interaction is nonlinear due to friction at the contact interfaces, and the linear superposition of their separate contributions cannot accurately estimate vibration amplitude. This study analytically obtains synchronous solutions with forcing and uses numerical continuation tools to track other solutions and their stability behavior. The results show nonlinear switching between flutter and forced response, and the presence of new frequency locked solutions in tuned rotors. The study provides insights into the interaction of flutter and forced response in turbomachinery systems.
NONLINEAR DYNAMICS
(2023)
Article
Mechanics
Chaofeng Li, Zilin Chen, Zengchuang Shen, Houxin She
Summary: This paper studies the vibration reduction characteristics of a flexible blade with a dovetail joint and underplatform damper. The influence of the platform mass on the blade's inherent characteristics is considered, and the underplatform is treated as a particle with mass. Two types of friction models are introduced on the blade's contact interfaces, and the normal pressure of these interfaces varies with the rotating speed of the blade. The dynamical equation for the rotating blade is established using the finite element method, and the effects of rotating speed, initial preload, and contact angle of the underplatform on the blade's vibration reduction are investigated.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2022)
Article
Engineering, Multidisciplinary
Ahmed Hussien, Abdelgalil Eltayesh, Hesham M. El-Batsh
Summary: PV panels are cooled by forced convection using different cooling methods, including small backside fans and blowers. Computational fluid dynamics (CFD) is used to analyze the cooling airflow characteristics and panel temperature distribution. Experimental measurements show that using small backside fans can significantly enhance the performance of PV panels with a maximum total increase of 2.1% in efficiency and 7.9% energy saving.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Acoustics
Florence Nyssen, Yann Colaitis, Alain Batailly
Summary: This work focuses on the numerical investigation of mistuned bladed disk dynamics undergoing blade-tip/casing contact events. The effect of mistuning on the bladed disk dynamics is evaluated, highlighting the importance of considering both time and frequency solution methods. The study reveals that time integration strategies may underestimate contact stiffening and maximum amplitudes in tuned bladed disks. Furthermore, the challenges of frequency methods on mistuned bladed disks are discussed, and a stochastic analysis is conducted to quantify the effect of mistuning on the bladed disk dynamics with contact nonlinearities.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Construction & Building Technology
Nadia M. Mirzai, Reza Attarnejad, Jong Wan Hu
Summary: Eccentrically braced frames with vertical shear links are lateral load resisting systems with considerable strength and ductility. A new hybrid damper proposed in this study aims to reduce deformation and damage to the main structure by earthquakes. Experimental results show that the proposed SMA damper significantly decreases residual displacement and provides substantial re-centering capability.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Engineering, Mechanical
E. P. Petrov
JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME
(2018)
Article
Engineering, Mechanical
Junjie Chen, Chaoping Zang, Biao Zhou, E. P. Petrov
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2019)
Article
Engineering, Mechanical
V Ondra, I. A. Sever, C. W. Schwingshackl
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2019)
Article
Engineering, Mechanical
D. Heller, I. A. Sever, C. W. Schwingshackl
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2020)
Article
Engineering, Mechanical
I. A. Sever, M. Maguire
Summary: This paper explores the use of a 3D laser measurement system for full-field dynamic strain measurements on compressor and turbine rotor blades. The results show a high degree of agreement between measured and predicted strains, demonstrating the maturity of the technology and the validity of the method used. Actual geometries were found to significantly impact the measurement results.
EXPERIMENTAL TECHNIQUES
(2021)
Article
Acoustics
V Ondra, I. A. Sever, C. W. Schwingshackl
Summary: Modal analysis is a well-established method for linear systems, but extending it to non-linear structures faces challenges. This paper adopts the definition of complex non-linear modes (CNMs) for mechanical systems and explores the identification of these modes using the Hilbert-Huang transform (HHT). The study shows that while HHT can detect and characterize non-linear behavior, it is limited in quantifying the behavior using CNMs.
JOURNAL OF SOUND AND VIBRATION
(2021)
Article
Engineering, Mechanical
D. Di Maio, G. Voudouris, I. A. Sever
Summary: The structural integrity of aerospace assets is crucial for the safety and economy of the aviation industry. However, fatigue in composites and vibration-induced fatigue are challenging due to the complex nature of the damage accumulation and the limited understanding of failure criteria. This research proposes a simulation-driven dynamic test framework to address these issues.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Aerospace
Manu Krishnan, Ibrahim A. Sever, Pablo Tarazaga
Summary: This study aims to develop accurate models for tracked order vibration in aircraft engines using data-driven modeling techniques. By analyzing the correlations between various thermomechanical variables and vibration, we can understand their interdependencies and use this knowledge to improve the modeling process.
Proceedings Paper
Engineering, Mechanical
Georgios Voudouris, Dario Di Maio, Ibrahim Sever
MODEL VALIDATION AND UNCERTAINTY QUANTIFICATION, VOL 3
(2020)
Article
Engineering, Mechanical
Georgios Voudouris, Dario Di Maio, Ibrahim A. Sever
INTERNATIONAL JOURNAL OF FATIGUE
(2020)
Proceedings Paper
Engineering, Mechanical
Manu Krishnan, Ran Jin, Ibrahim A. Sever, Pablo A. Tarazaga
SENSORS AND INSTRUMENTATION, AIRCRAFT/AEROSPACE, ENERGY HARVESTING & DYNAMIC ENVIRONMENTS TESTING, VOL 7
(2020)
Proceedings Paper
Engineering, Mechanical
Ibrahim A. Sever
MODEL VALIDATION AND UNCERTAINTY QUANTIFICATION, VOL 3
(2019)
Proceedings Paper
Engineering, Mechanical
Samson B. Cooper, Dario DiMaio, Ibrahim A. Sever, Sophoclis Patsias
MODEL VALIDATION AND UNCERTAINTY QUANTIFICATION, VOL 3
(2019)
Article
Computer Science, Interdisciplinary Applications
Rahul Rajasekharan, Evgeny Petrov
ENGINEERING REPORTS
(2019)
Proceedings Paper
Engineering, Mechanical
Daniel Heller, Ibrahim Sever, Christoph W. Schwingshackl
PROCEEDINGS OF THE ASME TURBO EXPO: TURBOMACHINERY TECHNICAL CONFERENCE AND EXPOSITION, 2018, VOL 7C
(2018)