Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration最新文献

{"title":"Development of a Multi-Shaker-Control to Investigate the Influence of the Interblade Phase Angle on Frictionally Damped Turbine Blades","authors":"F. Jäger, Ferhat Kaptan, L. P. Scheidt, J. Wallaschek","doi":"10.1115/gt2021-59272","DOIUrl":"https://doi.org/10.1115/gt2021-59272","url":null,"abstract":"\u0000 Constructive damper concepts are developed and integrated in turbomachinery to reduce vibration amplitudes generated by dynamic loads. The potential damping effectiveness of friction-based damper concepts is strongly dependent on the relative motion between adjacent blades, besides other factors such as normal force. In cyclic symmetric structures the phase difference is determined by the excited nodal diameter, which leads to different damper movements and efficiencies for given mode shapes. Several studies on the investigation of the damper performance of different underplatform damper geometries have been carried out on non-rotating test stands consisting usually of two blades in order to reduce the experimental effort before setting up rotational tests. Based on the existing modes of the two blades and the application of commonly just one shaker, the investigations are limited to the in-phase and out-of-phase modes. In this paper an experimental approach is developed to reduce the gap of transferability between non-rotating and rotational tests to analyze the effects of a variable interblade phase angle on the damping effect of underplatform dampers. For this purpose, a cascaded control system using two shakers is being developed to control the force amplitudes and the phase difference between the response of the two blades. The control algorithm is designed in a model-based way by using a two degrees of freedom oscillator with friction contact and is subsequently integrated in the non-rotating test stand.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117178847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technological Choices for Vibratory Robustness of Turbine Bladed Disk","authors":"M. Herran, Marc Dijoud, C. Colette","doi":"10.1115/gt2021-04281","DOIUrl":"https://doi.org/10.1115/gt2021-04281","url":null,"abstract":"\u0000 Robustness of gas turbine, turbojet or turboprop components with respect to vibratory stress is a guarantee of the success of developments made on time and in service reliability objectives achievement.\u0000 Currently, it is proposed to achieve the required robustness by components geometry optimization to reduce their mechanical stress levels. It may also be possible to improve the endurance limits of the materials. These optimizations and choices, consumers in time and complexity of manufacture, may be necessary when the required robustness is not found to be achieved during the engine verification. By taking the effects of potential uncertainties and dispersions into account earlier in the development process, technological choices may be more likely to achieve the desired robustness requirement.\u0000 This paper investigates several simple technological choices to control and reduce the vibratory levels present on the rotors of helicopter turboshaft engines. These technological choices are major choices in the engine architecture with or without additional parts to increase mechanical resistance margins.\u0000 Gas turbine architecture has a direct impact on the level of excitations and vibratory appropriations, particularly the choice of rotor-stator blade numbers or technologies and shapes of links between rotors. Additional parts allow to increase the vibratory margins on the scale of the component. In this category, the benefit of dampers and intentional mistuning will be recalled. Particular attention will be paid to the relative weight between these technological choices in comparison with the mistuning effect on dynamic levels.\u0000 Technological choices will be quantified and illustrated by mechanical and statistical analysis and experimental industrial examples.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129240734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved Rotor Design With Combined 3D-2D Probabilistic Approach","authors":"Lukas C. Schuchard, M. Voigt, R. Mailach, P. Dumstorff, Armin de Lazzer, Henning Almstedt","doi":"10.1115/gt2021-58620","DOIUrl":"https://doi.org/10.1115/gt2021-58620","url":null,"abstract":"\u0000 Availability and flexibility, largely in terms of start-up times, are becoming paramount for today’s steam turbine operation. Thus, precise knowledge of the stresses components experience and their lifetime consumption in transient regimes is vital for safe turbine operation. A typical lifetime-driving feature is low cycle fatigue in rotor grooves that is caused by rotor-blade root interaction and thermo-mechanical stresses.\u0000 In the course of a previous project at Technische Universität Dresden [1, 2] a 2D axisymmetric, transient thermo-mechanical model of an intermediate pressure steam turbine rotor had been developed for probabilistic analysis. Thereby, the blade root compound’s stiffness and the twisting of rhomboid blade roots in circumferential grooves, both of which cannot be modelled directly in 2D, were found to be key drivers for uncertainties in lifetime calculation.\u0000 To overcome these limitations, a 3D four-stage, fifteen-blade mechanical model for further analysis was created. The present work introduces this 3D model. It is then employed in a probabilistic sensitivity study to further refine the understanding of the influence of unknown or uncertain boundary conditions on the stresses that drive lifetime consumption. These results for stationary and exemplary transient operation are fed back into fine-tuning the existing 2D model in order to match the 3D calculated stresses. With its far lower computational effort the improved 2D model is well-suited for efficient future probabilistic analysis for robustness estimation and design space exploration.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":" 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113949295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Performance of Wave-Like Dry Friction and Piezoelectric Hybrid Flexible Dampers","authors":"Yaguang Wu, Yubo Fan, Lin Li, Z. Zhao","doi":"10.1115/GT2021-58817","DOIUrl":"https://doi.org/10.1115/GT2021-58817","url":null,"abstract":"\u0000 This paper proposes a flexible dry friction plate to mitigate the vibration of thin-walled structures for one resonance crossing. Based on a cantilever beam-friction damper finite element model, the geometry and material parameters of the friction plate are optimized numerically through steady-state response analyses by the widely-used Multi-Harmonic Balance Method (MHB-M). In order to further improve the damping effect, piezoelectric material is distributed to the flexible damper, and two types of dry friction and piezoelectric hybrid dampers are explored, namely semi-active and passive, respectively. For semi-active hybrid dampers, piezoelectric material is used as an actuator to adjust the normal load applied to the friction interface in real time, so that the friction damping is improved. For passive ones, piezoelectric material is used as a transducer, which dissipates the strain energy stored in the wave-like plate by the shunting circuit, additional shunted piezoelectric damping contributes to the total output damping accordingly. Better damping effect compared with the friction baseline is realized for the two types ideally. This damping module has a simple structure and avoids the problem of installation and maintenance of piezoelectric material which is generally bonded to the host structure. Technical challenges are: the semi-active type requires excessive voltage applied to the piezoelectric actuator, while the passive one needs to connect a programmable synthetic circuit.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124455301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method and Verification for Material Calibration of the Chaboche Plasticity Model for Multiple Material Directions","authors":"Charles R. Krouse, G. Musgrove, Taewoan Kim, Seungmin Lee, Muhyoung Lee, Seongyong Jeong","doi":"10.1115/gt2021-04132","DOIUrl":"https://doi.org/10.1115/gt2021-04132","url":null,"abstract":"\u0000 The Chaboche model is a well-validated non-linear kinematic hardening material model. This material model, like many models, depends on a set of material constants that must be calibrated for it to match the experimental data. Due to the challenge of calibrating these constants, the Chaboche model is often disregarded. The challenge with calibrating the Chaboche constants is that the most reliable method for doing the calibration is a brute force approach, which tests thousands of combinations of constants. Different sampling techniques and optimization schemes can be used to select different combinations of these constants, but ultimately, they all rely on iteratively selecting values and running simulations for each selected set. In the experience of the authors, such brute force methods require roughly 2,500 combinations to be evaluated in order to have confidence that a reasonable solution is found. This process is not efficient. It is time-intensive and labor-intensive. It requires long simulation times, and it requires significant effort to develop the accompanying scripts and algorithms that are used to iterate through combinations of constants and to calculate agreement. A better, more automated method exists for calibrating the Chaboche material constants.\u0000 In this paper, the authors describe a more efficient, automated method for calibrating Chaboche constants. The method is validated by using it to calibrate Chaboche constants for an IN792 single-crystal material and a CM247 directionally-solidified material. The calibration results using the automated approach were compared to calibration results obtained using a brute force approach. It was determined that the automated method achieves agreeable results that are equivalent to, or supersede, results obtained using the conventional brute force method.\u0000 After validating the method for cases that only consider a single material orientation, the automated method was extended to multiple off-axis calibrations. The Chaboche model that is available in commercial software, such as ANSYS, will only accept a single set of Chaboche constants for a given temperature. There is no published method for calibrating Chaboche constants that considers multiple material orientations. Therefore, the approach outlined in this paper was extended to include multiple material orientations in a single calibration scheme. The authors concluded that the automated approach can be used to successfully, accurately, and efficiently calibrate multiple material directions. The approach is especially well-suited when off-axis calibration must be considered concomitantly with longitudinal calibration. Overall, the automated Chaboche calibration method yielded results that agreed well with experimental data. Thus, the method can be used with confidence to efficiently and accurately calibrate the Chaboche non-linear kinematic hardening material model.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"271 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132948446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gaussian Stochastic Process Modeling of Blend Repaired Airfoil Modal Response Using Reduced Basis Mode Shape Approach","authors":"Jeffrey M. Brown, A. Kaszynski, Daniel L. Gillaugh, Emily B. Carper, Joseph A. Beck","doi":"10.1115/gt2021-60238","DOIUrl":"https://doi.org/10.1115/gt2021-60238","url":null,"abstract":"\u0000 A machine learning (ML) approach is developed to predict the effect of blend repairs on airfoil frequency, modal assurance criterion (MAC), and modal displacement vectors. The method is demonstrated on a transonic research rig compressor rotor airfoil. A parametric definition of blend geometry is developed and shown to be capable of encompassing a large range of blend geometry. This blend repair geometry is used to modify the airfoil surface definition and a mesh morphing process transforms the nominal finite element model (FEM) to the repaired configuration. A multi-level full factorial sampling of the blend repair design space provides training data to a Guassian stochastic process (GSP) regressor. The frequency and MAC results create a vector of training data for GSP calibration, but the airfoil mode shapes require further mathematical manipulation to avoid creating GSP models for each nodal displacement. This paper develops a method to significantly reduce blended airfoil mode shape emulation cost by transforming the mode shape training data into a reduced basis space using principal component analysis (PCA). The coefficients of this reduced basis are used to train a GSP that can then predict the values for new blended airfoils. The emulated coefficients are used with the reduced basis vectors in a reconstruction of blended airfoil mode shape. Validation data is computed at a full-factorial design that maximizes the distance from training points. It is found that large variations in modal properties from large blend repairs can be accurately emulated with a reasonable number of training points. The reduced basis approach of mode shape variation is shown to more accurately predict MAC variation when compared to direct MAC emulation. The added benefit of having the full modal displacement field also allows determination of other influences such as tip-timing limits and modal force values.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123341003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous Optimization of Mistuned Bladed Disks for Forced and Self-Excited Vibration Considering Amount of Unbalance","authors":"Y. Kaneko, Toshio Watanabe, T. Furukawa","doi":"10.1115/gt2021-58470","DOIUrl":"https://doi.org/10.1115/gt2021-58470","url":null,"abstract":"\u0000 Actual bladed disks with small variations are called mistuned systems. Many researchers suggest that mistuning, although negatively affecting the forced response, has a beneficial (stabilizing) effect on blade flutter (self-excited vibration). Therefore, in blade design, a bladed disk must be optimized for forced vibration and blade flutter. We proposed a simultaneous optimization method of bladed disks for forced and self-excited vibration, considering the amount of unbalance that causes rotor vibration. This method uses alternate mistuning to suppress the blade flutter. We measured the natural frequency and weight of all the blades of a disk, as in the traditional development process. Then, we assembled a mistuned system retaining the alternate mistuning, and generated analysis models based on the measured natural frequencies and weights of the blades. Finally, we analyzed the resonant stress and the amount of unbalance in the mistuned system repeatedly, sorting the blades and retaining the alternate mistuning of the disk. The simultaneous optimal solution was explored by MCS or DDE (Genetic algorithm). To reduce the computational time, we used the reduced order model FMM to calculate the resonant stress and the stability of the mistuned bladed disks. Further, we verified the validity of the proposed method by applying it to a mistuned bladed disk of a steam turbine.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122585221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Probabilistic Machine Learning Framework for Explicit Inverse Design of Industrial Gas Turbine Blades","authors":"Sayan Ghosh, Valeria Andreoli, G. A. Padmanabha, Cheng Peng, Steven Atkinson, Piyush Pandita, T. Vandeputte, N. Zabaras, Liping Wang","doi":"10.1115/gt2021-58842","DOIUrl":"https://doi.org/10.1115/gt2021-58842","url":null,"abstract":"\u0000 One of the critical components in Industrial Gas Turbines (IGT) is the turbine blade. Design of turbine blades needs to consider multiple aspects like aerodynamic efficiency, durability, safety and manufacturing, which make the design process sequential and iterative. The sequential nature of these iterations forces a long design cycle time, ranging from a several months to years. Due to the reactionary nature of these iterations, little effort has been made to accumulate data in a manner that allows for deep exploration and understanding of the total design space. This is exemplified in the process of designing the individual components of the IGT resulting in a potential unrealized efficiency. To overcome the aforementioned challenges, we demonstrate a probabilistic inverse design machine learning framework, namely Pro-ML IDeAS, to carry out an explicit inverse design. Pro-ML IDeAS calculates the design explicitly without costly iteration and overcomes the challenges associated with ill-posed inverse problems. In this work the framework will be demonstrated on inverse aerodynamic design of 2D airfoil of turbine blades.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131278734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bayesian Optimization for Multi-Objective High-Dimensional Turbine Aero Design","authors":"Yiming Zhang, Sayan Ghosh, T. Vandeputte, Liping Wang","doi":"10.1115/gt2021-59745","DOIUrl":"https://doi.org/10.1115/gt2021-59745","url":null,"abstract":"\u0000 Industrial design fundamentally relies on high-dimensional multi-objective optimization. Bayesian Optimization (BO) based on Gaussian Processes (GPs) has been shown to be effective for this practice where new designs are picked in each iteration for varying objectives including optimization and model refinement. This paper introduces two industrial applications of BO for turbine aero design. The first application is GE’s Aviation & Power DT4D Turbo Aero Design with 32 design variables. It has a single objective to maximize with 32 input/design variables and thus considered high-dimensional in terms of the input space. BO has significantly succeeded the traditional design schemes. It has been shown that finding the maximum-EI points (inner-loop optimization) could be critical and the influence of inner-loop optimization was evaluated. The second application is for multi-objective optimization. Each simulation run is the aggregate result from multiple CFD runs tuning geometry and took 24 hours to complete. BO has been capable to extend the existing Pareto front with a few additional runs. BO has been searching along the border of the design space and therefore motivate the open-up of design space exploration. For both applications, BO successfully guide the CFD run and allocate design variables more optimum than previous design approaches.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115582325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and Tests of a New Damper for a Gas Turbine Thin-Shell Duct","authors":"S. Gabriele, Paolo di Sisto, G. D. Vescovo, Conti Simone","doi":"10.1115/gt2021-58919","DOIUrl":"https://doi.org/10.1115/gt2021-58919","url":null,"abstract":"\u0000 Gas turbine (GT) liners, transition ducts and exhaust diffusers are large thin-shell ducts bounded by two barrels, typically characterized by multiple natural frequencies inside the operating speed range of the engine rotor.\u0000 In most applications, GT ducts are supported on one side only and they are free to expand inside the gas turbine so to avoid thermal distresses.\u0000 The GT ducts are typically damped structures able to prevent high cycles fatigue failures. Damping is provided by sliding features as insulation or bolted joints.\u0000 This paper describes the redesign of a transition duct (TD) after it was discovered that in some operating conditions, duct could crack for high cycle fatigue (HCF).\u0000 The TD connects the flow path of the gas generator turbine with the flow path of the power turbine.\u0000 The new TD has been made more robust, but it has also been equipped of dampers capable to operate at high temperature.\u0000 Starting from the analyses of field data, a predictive FEA model has been developed and validated. After a deep investigation of the TD modes that could be excited by flow path and/or by rotor vibrations, it was decided to add two dampers, one for each barrel of the TD.\u0000 Due to internal space limitations, a new type of damper has been designed for the external barrel.\u0000 Both dampers have been sized using FEA. Harmonic analyses rather than forced response transient analyses have been performed so to verify the effectiveness of the new design. In the simulations, dampers have been replaced by harmonic forces able to reproduce the friction force of the dampers.\u0000 Validation of the method and damper calibration has been done by performing lab tests and full-size TD tests.","PeriodicalId":143309,"journal":{"name":"Volume 9B: Structures and Dynamics — Fatigue, Fracture, and Life Prediction; Probabilistic Methods; Rotordynamics; Structural Mechanics and Vibration","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125286045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}