Forced Response Variation of a Compressor Utilizing Blade Tip Timing, Strain Gages, and As-Manufactured Finite Element Models

2021 ◽  
Author(s):  
Daniel Gillaugh ◽  
Timothy Janczewski ◽  
Alex Kaszynski ◽  
Jeffrey Brown ◽  
Joseph Beck ◽  
...  
Keyword(s):  
Finite Element ◽  
Strain Gage ◽  
Model Updating ◽  
Forced Response ◽  
Finite Element Models ◽  
Turbine Engine ◽  
Blade Tip ◽  
Response Variation ◽  
Updating Procedure ◽  
Engine Components

Abstract The dynamic response of turbine engine components varies widely due to manufacturing deviations in the blades known as mistuning. This dynamic variation is investigated using a single stage compressor experimentally using both blade tip timing (BTT) and strain gage (SG) measurements and using as-manufactured finite element models (AMMs) on a 1st bend mode. Operational BTT and SG safety limits were generated using both averaged and AMM models via Goodman material properties. The predicted individual blade stress/deflection (S/D) ratios and strain gage ratios for this mode will be compared to the average finite element counterparts. Additionally, the correlation between BTT and SG's will be presented. This correlation will be performed using two approaches: blade maximum stress comparisons and measured response compared to the sensors safety limits. It will be shown that accounting for geometry with AMMs produce more accurate strain gage to BTT correlation compared to average models. An experimental model updating procedure is developed to increase the strain gage to BTT correlation by optimizing the location the BTT optical spot probes measure on the blade chord. Implementing this procedure using as-manufactured models are able to improve strain gage to BTT correlation.

Forced Response Variation of a Compressor Utilizing Blade Tip Timing, Strain Gages, and As-Manufactured Finite Element Models

2020 ◽  
Author(s):  
Daniel L. Gillaugh ◽  
Timothy J. Janczewski ◽  
Alexander A. Kaszynski ◽  
Jeffrey M. Brown ◽  
Joseph A. Beck ◽  
...  
Keyword(s):  
Finite Element ◽  
Strain Gage ◽  
Model Updating ◽  
Forced Response ◽  
Finite Element Models ◽  
Turbine Engine ◽  
Blade Tip ◽  
Response Variation ◽  
Updating Procedure ◽  
Engine Components

Abstract The dynamic response of turbine engine components varies widely due to manufacturing deviations in the blades known as mistuning. This dynamic variation is investigated using a single stage compressor experimentally using both blade tip timing (BTT) and strain gage (SG) measurements and using as-manufactured finite element models (AMMs) on a 1st bend mode. Operational BTT and SG safety limits were generated using both averaged and AMM models via Goodman material properties. The predicted individual blade stress/deflection (S/D) ratios and strain gage ratios for this mode will be compared to the average finite element counterparts. Additionally, the correlation between BTT and SG’s will be presented. This correlation will be performed using two approaches: blade maximum stress comparisons and measured response compared to the sensors safety limits. It will be shown that accounting for geometry with AMMs produce more accurate strain gage to BTT correlation compared to average models. An experimental model updating procedure is developed to increase the strain gage to BTT correlation by optimizing the location the BTT optical spot probes measure on the blade chord. Implementing this procedure using as-manufactured models are able to improve strain gage to BTT correlation.

Forced Response Variation of a Compressor Utilizing Blade Tip Timing, Strain Gages, and As-Manufactured Finite Element Models

2021 ◽  
Author(s):  
Daniel Gillaugh ◽  
Alex Kaszynski ◽  
Timothy Janczewski ◽  
Jeffrey Brown ◽  
Chase Nessler ◽  
...  
Keyword(s):  
Finite Element ◽  
Forced Response ◽  
Finite Element Models ◽  
Strain Gages ◽  
Blade Tip ◽  
Response Variation

Validating and Updating Finite Element Models Using Experimental Measurements of Dynamics

1990 ◽  
Vol 204 (1) ◽  
pp. 45-50
Author(s):  
C F McCulloch ◽  
P Vanhonacker ◽  
E Dascotte
Keyword(s):  
Finite Element ◽  
Structural Dynamics ◽  
Model Updating ◽  
Measured Data ◽  
Physical Parameters ◽  
Experimental Measurements ◽  
Finite Element Models ◽  
Data Sets ◽  
Modal Data ◽  
Modelling Assumptions

A method is proposed for updating finite element models of structural dynamics using the results of experimental modal analysis, based on the sensitivities to changes in physical parameters. The method avoids many of the problems of incompatibility and inconsistency between the experimental and analytical modal data sets and enables the user to express confidence in measured data and modelling assumptions, allowing flexible but automated model updating.

Application of a FRF Based Model Updating Technique for the Validation of Finite Element Models of Components of the Automotive Industry

1995 ◽  
Author(s):  
Stefan Lammens ◽  
Marc Brughmans ◽  
Jan Leuridan ◽  
Ward Heylen ◽  
Paul Sas
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Automotive Industry ◽  
Stiffness Matrix ◽  
Model Updating ◽  
Dynamic Stiffness ◽  
Element Model ◽  
Model Parameters ◽  
Finite Element Models ◽  
Analytical Dynamic

Abstract This paper presents two applications of the RADSER model updating technique (Lammens et al. (1995) and Larsson (1992)). The RADSER technique updates finite element model parameters by solution of a linearised set of equations that optimise the Reduced Analytical Dynamic Stiffness matrix based on Experimental Receptances. The first application deals with the identification of the dynamic characteristics of rubber mounts. The second application validates a coarse finite element model of a subframe of a Volvo 480.

scholarly journals Infill Modelling Influence on Dynamic Identification and Model Updating of Reinforced Concrete Framed Buildings

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Marco Bovo ◽  
Michele Tondi ◽  
Marco Savoia
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Model Updating ◽  
Numerical Models ◽  
Finite Element Models ◽  
Dynamic Tests ◽  
Large Variability ◽  
Equivalent Strut ◽  
Infill Panels ◽  
Wide Range

In order to correctly capture the dynamic behavior of infilled framed buildings, the importance to take into account in seismic design the infill panels’ contribution is nowadays well recognized since they could modify in a significant way the global and local response of the whole building. Despite about sixty years of continuous research in the field, the modelling of the frame-infill interaction still represents a serious issue for the daily practical design since there is no reference model proven to be suitable to cover a wide record of possible cases. Moreover, few works are available in the literature, comparing the results of different modelling proposals with outcomes of dynamic tests on a full-scale building. To this regard, starting from the results of induced vibration dynamic tests performed on a 7-story building with reinforced concrete frames with masonry infill, in the present paper, the effects of the infill presence have been evaluated by comparing experimental outcomes, achieved using a MDOF Circle-Fit identification procedure, with the results obtained by means of numerical analyses performed on finite element models. Using a model updating procedure, the optimal width to assign to the masonry equivalent struts modelling the infill panels was defined. Furthermore, several literature proposals for the definition of the equivalent strut width have been analysed. Thirteen different proposals have been selected and implemented in thirteen different finite element models. The reliability of each proposal has been investigated and quantified by comparing the dynamic properties of the models with the building dynamic response obtained by the experimental tests. The main outcomes of the analyses highlight that different proposals provide a great variability for the strut width. This brings to a large variability of the mechanical properties of the equivalent struts, and as a consequence, the modelling choice also influences the dynamic behaviour of the numerical models. Currently, this represents a serious issue for the daily designers’ activity. The outcomes provided in the paper, although established for a specific case study, can be extended to a wide range of buildings and should drive the future research studies in order to provide more robust criteria for the modelling of this worldwide building class.

Fracture Prediction for the Proximal Femur Using Finite Element Models: Part I—Linear Analysis

1991 ◽  
Vol 113 (4) ◽  
pp. 353-360 ◽  
Author(s):  
J. C. Lotz ◽  
E. J. Cheal ◽  
W. C. Hayes
Keyword(s):  
Finite Element ◽  
Fracture Risk ◽  
Strain Gage ◽  
Proximal Femur ◽  
Material Properties ◽  
The United States ◽  
Nonlinear Material ◽  
Finite Element Models ◽  
Model Predictions

Over 90 percent of the more than 250,000 hip fractures that occur annually in the United States are the result of falls from standing height. Despite this, the stresses associated with femoral fracture from a fall have not been investigated previously. Our objectives were to use three-dimensional finite element models of the proximal femur (with geometries and material properties based directly on quantitative computed tomography) to compare predicted stress distributions for one-legged stance and for a fall to the lateral greater trochanter. We also wished to test the correspondence between model predictions and in vitro strain gage data and failure loads for cadaveric femora subjected to these loading conditions. An additional goal was to use the model predictions to compare the sensitivity of several imaging sites in the proximal femur which are used for the in vivo prediction of hip fracture risk. In this first of two parts, linear finite element models of two unpaired human cadaveric femora were generated. In Part II, the models were extended to include nonlinear material properties for the cortical and trabecular bone. While there was poor correspondence between strain gage data and model predictions, there was excellent agreement between the in vitro failure data and the linear model, especially using a von Mises effective strain failure criterion. Both the onset of structural yielding (within 22 and 4 percent) and the load at fracture (within 8 and 5 percent) were predicted accurately for the two femora tested. For the simulation of one-legged stance, the peak stresses occurred in the primary compressive trabeculae of the subcapital region. However, for a simulated fall, the peak stresses were in the intertrochanteric region. The Ward’s triangle (basicervical) site commonly used for the clinical assessment of osteoporosis was not heavily loaded in either situation. These findings suggest that the intertrochanteric region may be the most sensitive site for the assessment of fracture risk due to a fall and the subcapital region for fracture risk due to repetitive activities such as walking.

Experimental and Numerical Correlation of Impact of Spherical Projectile for Damage Analysis of Aero Engine Component

2016 ◽  
Vol 66 (2) ◽  
pp. 193 ◽  
Author(s):  
Anuradha Nayak Majila ◽  
Rajeev Jain ◽  
Chandru Fernando D. ◽  
S. Ramachandra
Keyword(s):  
Finite Element ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Metallographic Analysis ◽  
Damage Analysis ◽  
Alloy Plate ◽  
Turbine Engine ◽  
Aero Engine ◽  
Engine Components ◽  
The Impact

<p>Studies the impact response of flat Titanium alloy plate against spherical projectile for damage analysis of aero engine components using experimental and finite element techniques. Compressed gas gun has been used to impart speed to spherical projectile at various impact velocities for damage studies. Crater dimensions (diameter and depth) obtained due to impact have been compared with finite element results using commercially available explicit finite element method code LS-DYNA. Strain hardening, high strain rate and thermal softening effect along with damage parameters have been considered using modified Johnson-Cook material model of LS-DYNA. Metallographic analysis has been performed on the indented specimen. This analysis is useful to study failure analysis of gas turbine engine components subjected to domestic object damage of gas turbine engine. </p><p> </p>

scholarly journals A Study on Fluid Self-Excited Flutter and Forced Response of Turbomachinery Rotor Blade

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Chih-Neng Hsu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Power Plants ◽  
Single Mode ◽  
Element Model ◽  
Forced Response ◽  
Structural Dynamic ◽  
Turbine Engine ◽  
Forcing Function ◽  
Structural Dynamic Characteristics

Complex mode and single mode approach analyses are individually developed to predict blade flutter and forced response. These analyses provide a system approach for predicting potential aeroelastic problems of blades. The flow field properties of a blade are analyzed as aero input and combined with a finite element model to calculate the unsteady aero damping of the blade surface. Forcing function generators, including inlet and distortions, are provided to calculate the forced response of turbomachinery blading. The structural dynamic characteristics are obtained based on the blade mode shape obtained by using the finite element model. These approaches can provide turbine engine manufacturers, cogenerators, gas turbine generators, microturbine generators, and engine manufacturers with an analysis system to remedy existing flutter and forced response methods. The findings of this study can be widely applied to fans, compressors, energy turbine power plants, electricity, and cost saving analyses.

scholarly journals Structural Optimization Coupled with Materials Selection for Stiffness Improvement

2020 ◽  
Vol 22 (4) ◽  
pp. 831-844
Author(s):  
Hugo Miguel Silva ◽  
José Filipe Meireles ◽  
Jerzy Wojewoda
Keyword(s):  
Finite Element ◽  
Model Updating ◽  
Optimization Procedure ◽  
Element Model ◽  
Finite Element Models ◽  
Materials Selection ◽  
Reinforced Plate ◽  
Selection For ◽  
Geometric Variables ◽  
Matlab Programming

AbstractAn application of a Finite Element Model updating is presented in this paper. Two Finite Element models were considered: a reinforced plate and a thin-walled beam. The two parts were numerically calculated in ANSYS Mechanical APDL and MATLAB programs. ANSYS performs Finite Element calculations, and a MATLAB programming code was used to control the optimization procedure. Geometric variables were chosen, to evaluate the value of the defined objective function. The material was picked using available selection charts, to find the most adequate one for the study. It has been concluded that the transveral displacement of the models modified by the optimization process decreased sharply in relation to the original state.

scholarly journals How to compute invariant manifolds and their reduced dynamics in high-dimensional finite element models

2021 ◽  
Author(s):  
Shobhit Jain ◽  
George Haller
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Invariant Manifolds ◽  
Mechanical Systems ◽  
Forced Response ◽  
High Dimensional ◽  
Nonlinear Phenomena ◽  
Finite Element Models ◽  
Engineering Structures ◽  
Backbone Curves

AbstractInvariant manifolds are important constructs for the quantitative and qualitative understanding of nonlinear phenomena in dynamical systems. In nonlinear damped mechanical systems, for instance, spectral submanifolds have emerged as useful tools for the computation of forced response curves, backbone curves, detached resonance curves (isolas) via exact reduced-order models. For conservative nonlinear mechanical systems, Lyapunov subcenter manifolds and their reduced dynamics provide a way to identify nonlinear amplitude–frequency relationships in the form of conservative backbone curves. Despite these powerful predictions offered by invariant manifolds, their use has largely been limited to low-dimensional academic examples. This is because several challenges render their computation unfeasible for realistic engineering structures described by finite element models. In this work, we address these computational challenges and develop methods for computing invariant manifolds and their reduced dynamics in very high-dimensional nonlinear systems arising from spatial discretization of the governing partial differential equations. We illustrate our computational algorithms on finite element models of mechanical structures that range from a simple beam containing tens of degrees of freedom to an aircraft wing containing more than a hundred–thousand degrees of freedom.

Sign in / Sign up

Export Citation Format

Share Document