scholarly journals A Reduced Order Modeling Approach to Probabilistic Creep-Damage Predictions in Finite Element Analysis

2021 ◽  
Author(s):  
Md Abir Hossain ◽  
Jacqueline R. Cottingham ◽  
Calvin M. Stewart
Keyword(s):  
Finite Element ◽  
Computational Cost ◽  
Creep Damage ◽  
Reduced Order Modeling ◽  
Full Scale ◽  
Spatial Uncertainty ◽  
304 Stainless Steel ◽  
Probabilistic Prediction ◽  
Reduced Order ◽  
Finite Element Software

Abstract This paper introduces a computationally efficient Reduced Order Modeling (ROM) approach for the probabilistic prediction of creep-damage failure. Component-level probabilistic simulations are needed to assess the reliability and safety of high-temperature components. Full-scale probabilistic creep-damage modeling in finite element (FE) approach is computationally expensive requiring many hundreds of simulations to replicate the uncertainty of component failure. To that end, ROM is proposed to minimize the elevated computational cost while controlling the loss of accuracy. It is proposed that full-scale probabilistic simulations can be completed in 1D at a reduced cost, the extremum conditions extracted, and those conditions applied for lower cost 2D/3D probabilistic simulations of components that capture the mean and uncertainty of failure. The probabilistic Sine-hyperbolic (Sinh) model is selected which in previous work was calibrated to alloy 304 stainless steel. The Sinh model includes probability density functions (pdfs) for test condition (stress and temperature), initial damage (i.e., microstructure), and material properties uncertainty. The Sinh model is programmed into ANSYS finite element software using the USERCREEP.F material subroutine. First, the Sinh model and FE code are subject to verification and validation to affirm the accuracy of the simulations. Numerous Monte Carlo simulations are executed in a 1D model to generate probabilistic creep deformation, damage, and rupture data. This data is analyzed and the probabilistic parameters corresponding to extreme creep response are extracted. The ROM concept is applied where only the extreme conditions are applied in the 2D probabilistic prediction of a component. The probabilistic predictions between the 1D and 2D model is compared to assess ROM for creep. The accuracy of the probabilistic prediction employing the ROM approach will potentially reduce the time and cost of simulating complex engineering systems. Future studies will introduce multi-stage Sinh, stochasticity, and spatial uncertainty for improved prediction.

scholarly journals Component-Mode-Based Reduced Order Modeling Techniques for Mistuned Bladed Disks—Part II: Application

2000 ◽  
Vol 123 (1) ◽  
pp. 100-108 ◽  
Author(s):  
R. Bladh ◽  
M. P. Castanier ◽  
C. Pierre
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Computational Cost ◽  
Theoretical Models ◽  
Companion Paper ◽  
Reduced Order Modeling ◽  
Bladed Disks ◽  
Reduced Order ◽  
Component Interface ◽  
Forced Responses

In this paper, the component-mode-based methods formulated in the companion paper (Part I: Theoretical Models) are applied to the dynamic analysis of two example finite element models of bladed disks. Free and forced responses for both tuned and mistuned rotors are considered. Comprehensive comparisons are made among the techniques using full system finite element solutions as a benchmark. The accurate capture of eigenfrequency veering regions is of critical importance for obtaining high-fidelity predictions of the rotor’s sensitivity to mistuning. Therefore, particular attention is devoted to this subject. It is shown that the Craig–Bampton component mode synthesis (CMS) technique is robust and yields highly reliable results. However, this is achieved at considerable computational cost due to the retained component interface degrees of freedom. It is demonstrated that this problem is alleviated by a secondary modal analysis reduction technique (SMART). In addition, a non-CMS mistuning projection method is considered. Although this method is elegant and accurate, it is seen that it lacks the versatility and efficiency of the CMS-based SMART. Overall, this work shows that significant improvements on the accuracy and efficiency of current reduced order modeling methods are possible.

scholarly journals Industrial Digital Twins based on the non-linear LATIN-PGD

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Philippe Barabinot ◽  
Ronan Scanff ◽  
Pierre Ladevèze ◽  
David Néron ◽  
Bruno Cauville
Keyword(s):  
Finite Element ◽  
High Performance ◽  
Reduced Order Modeling ◽  
Computational Time ◽  
Reduced Order ◽  
Finite Element Software ◽  
Digital Twins ◽  
Non Linear ◽  
Industrial Level ◽  
Early Design Phase

AbstractDigital Twins, which tend to intervene over the entire life cycle of products from early design phase to predictive maintenance through optimization processes, are increasingly emerging as an essential component in the future of industries. To reduce the computational time reduced-order modeling (ROM) methods can be useful. However, the spread of ROM methods at an industrial level is currently hampered by the difficulty of introducing them into commercial finite element software, due to the strong intrusiveness of the associated algorithms, preventing from getting robust and reliable tools all integrated in a certified product. This work tries to circumvent this issue by introducing a weakly-invasive reformulation of the LATIN-PGD method which is intended to be directly embedded into Simcenter Samcef$$^{\hbox {TM}}$$ TM finite element software. The originality of this approach lies in the remarkably general way of doing, allowing PGD method to deal with not only a particular application but with all facilities already included in such softwares—any non-linearities, any element types, any boundary conditions...—and thus providing a new high-performance all-inclusive non-linear solver.

Component-Mode-Based Reduced Order Modeling Techniques for Mistuned Bladed Disks: Part II — Application

2000 ◽  
Author(s):  
Ronnie Bladh ◽  
Matthew P. Castanier ◽  
Christophe Pierre
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Computational Cost ◽  
Theoretical Models ◽  
Companion Paper ◽  
Reduced Order Modeling ◽  
Bladed Disks ◽  
Reduced Order ◽  
Component Interface ◽  
Forced Responses

In this paper, the component-mode-based methods formulated in the companion paper (Part I: Theoretical Models) are applied to the dynamic analysis of two example finite element models of bladed disks. Free and forced responses for both tuned and mistuned rotors are considered. Comprehensive comparisons are made among the techniques using full system finite element solutions as a benchmark. The accurate capture of eigenfrequency veering regions is of critical importance for obtaining high-fidelity predictions of the rotor’s sensitivity to mistuning. Therefore, particular attention is devoted to this subject. It is shown that the Craig-Bampton component mode synthesis (CMS) technique is robust and yields highly reliable results. However, this is achieved at considerable computational cost due to the retained component interface degrees of freedom (DOF). It is demonstrated that this problem is alleviated by a secondary modal analysis reduction technique (SMART). In addition, a non-CMS mistuning projection method is considered. Although this method is elegant and accurate, it is seen that it lacks the versatility and efficiency of the CMS-based SMART. Overall, this work shows that significant improvements on the accuracy and efficiency of current reduced order modeling methods are possible.

How Adaptively Constructed Reduced Order Models Can Benefit Sampling-Based Methodsfor Reliability Analyses

2016 ◽  
Vol 23 (05) ◽  
pp. 1650019 ◽  
Author(s):  
Christian Gogu ◽  
Anirban Chaudhuri ◽  
Christian Bes
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Reliability Analysis ◽  
Computational Cost ◽  
Reduced Order Modeling ◽  
Finite Element Models ◽  
Reduced Order Models ◽  
Reduced Basis ◽  
Reduced Order ◽  
Separable Monte Carlo

Many sampling-based approaches are currently available for calculating the reliability of a design. The most efficient methods can achieve reductions in the computational cost by one to several orders of magnitude compared to the basic Monte Carlo method. This paper is specifically targeted at sampling-based approaches for reliability analysis, in which the samples represent calls to expensive finite element models. The aim of this paper is to illustrate how these methods can further benefit from reduced order modeling to achieve drastic additional computational cost reductions, in cases where the reliability analysis is carried out on finite element models. Standard Monte Carlo, importance sampling, separable Monte Carlo and a combined importance separable Monte Carlo approach are presented and coupled with reduced order modeling. An adaptive construction of the reduced basis models is proposed. The various approaches are compared on a thermal reliability design problem, where the coupling with the adaptively constructed reduced order models is shown to further increase the computational efficiency by up to a factor of six.

An Extrema Approach to Probabilistic Creep Modeling in Finite Element Analysis

2021 ◽  
Author(s):  
Md Abir Hossain ◽  
Jacqueline R Cottingham ◽  
Calvin M. Stewart
Keyword(s):  
Finite Element ◽  
Goodness Of Fit ◽  
Full Scale ◽  
Spatial Uncertainty ◽  
304 Stainless Steel ◽  
Computational Time ◽  
Extremum Condition ◽  
Wide Range ◽  
Extremum Conditions ◽  
2D Model

Abstract This paper introduces a computationally efficient extremum condition-based Reduced Order Modeling (ROM) approach for the probabilistic predictions of creep in finite element (FE). Component-level probabilistic simulations are needed to assess the reliability and safety of high-temperature components. Full-scale probabilistic creep models in FE are computationally expensive, requiring many hundreds of simulations to replicate the uncertainty of component failure. In this study, an extremum condition-based ROM approach is proposed. In the extremum approach, full-scale probabilistic simulations are completed in 1D across a wide range of stresses, the data is processed and extremum conditions extracted, and those conditions alone are applied in 2D/3D FE to predict the mean and range of creep-failure. The probabilistic Sinh model, calibrated for alloy 304 stainless steel, is selected . The uncertainty sources (i.e. test condition, pre-existing damage, and model constants) are evaluated and pdfs sampling are performed via Monte carlo method. The extremum conditions are chosen from numerous 1D model simulations. These conditions include extremum cases of creep ductility, rupture, and area under creep curves. Only the extremum cases are simulated for 2D model saving significant computational time and memory. The goodness-of-fit of the predicted creep response for 1D and 2D model shows satisfactory agreement with the experimental data. The accuracy of the extremum condition-based ROM will reduce significant computational burden of simulating complex engineering systems. Introduction of multi-stage Sinh, stochasticity, and spatial uncertainty will further improve the prediction.

scholarly journals A Proper Generalized Decomposition (PGD) approach to crack propagation in brittle materials: with application to random field material properties

2019 ◽  
Vol 65 (2) ◽  
pp. 451-473 ◽  
Author(s):  
Hasini Garikapati ◽  
Sergio Zlotnik ◽  
Pedro Díez ◽  
Clemens V. Verhoosel ◽  
E. Harald van Brummelen
Keyword(s):  
Crack Propagation ◽  
Material Properties ◽  
Computational Cost ◽  
Brittle Materials ◽  
Energy Criterion ◽  
Reduced Order Modeling ◽  
Proper Generalized Decomposition ◽  
Modeling Framework ◽  
Global Energy ◽  
Reduced Order

Abstract Understanding the failure of brittle heterogeneous materials is essential in many applications. Heterogeneities in material properties are frequently modeled through random fields, which typically induces the need to solve finite element problems for a large number of realizations. In this context, we make use of reduced order modeling to solve these problems at an affordable computational cost. This paper proposes a reduced order modeling framework to predict crack propagation in brittle materials with random heterogeneities. The framework is based on a combination of the Proper Generalized Decomposition (PGD) method with Griffith’s global energy criterion. The PGD framework provides an explicit parametric solution for the physical response of the system. We illustrate that a non-intrusive sampling-based technique can be applied as a post-processing operation on the explicit solution provided by PGD. We first validate the framework using a global energy approach on a deterministic two-dimensional linear elastic fracture mechanics benchmark. Subsequently, we apply the reduced order modeling approach to a stochastic fracture propagation problem.

Prediction of Creep Life on Notched Bar Specimens of Grade 92 Steel

2016 ◽  
Author(s):  
Haruhisa Shigeyama ◽  
Yukio Takahashi ◽  
Jonathan Parker
Keyword(s):  
Finite Element ◽  
Creep Damage ◽  
Creep Data ◽  
Creep Failure ◽  
Creep Tests ◽  
Energy Fraction ◽  
Damage Models ◽  
Finite Element Software ◽  
Notched Specimens ◽  
Life Fraction

Creep tests on two kinds of circumferentially notched round bar specimens as well as plain bar specimen were performed to obtain the multiaxial and uniaxial creep data. Creep damage models of strain fraction and energy fraction rule were developed using these creep data. Then creep damage analyses using a finite element software, MSC Marc, were carried out on notched specimens of both types and creep failure lives were predicted using the creep damage models of classical life fraction rule and developed strain or energy fraction rule. Experimental failure lives of all the conditions of notched specimens were compared with analytical results. As a result, creep failure lives obtained by life fraction rule were underestimated in the short term region and overestimated in the long term region. On the other hands, it is apparent that the majority of creep failure lives obtained by strain and energy fraction rule were predicted with an accuracy within a factor of two. Furthermore, some interrupted creep tests and creep void observations were conducted on the notched specimens of both types. The distributions of creep void number density were in good agreement with the distributions of creep damage calculated by finite element analyses.

Non-linear PGD Reduced-order model for industrial finite element software

2021 ◽  
Author(s):  
Ronan Scanff ◽  
David Néron ◽  
Pierre Ladevèze ◽  
Philippe Barabinot ◽  
Frédéric Cugnon ◽  
...  
Keyword(s):  
Finite Element ◽  
Reduced Order Model ◽  
Order Model ◽  
Reduced Order ◽  
Finite Element Software ◽  
Non Linear

Forced Response of a Mistuned Industrial Impeller With Two Different Blade Geometries, via ROM

2012 ◽  
Author(s):  
Luis A. Boulton ◽  
Euro Casanova
Keyword(s):  
Finite Element ◽  
Laser Scanning ◽  
Computational Cost ◽  
Forced Response ◽  
Dynamic Features ◽  
Reduced Order ◽  
Localization Phenomenon ◽  
Compressor Impeller ◽  
Cyclic Symmetric ◽  
Blade Geometry

Numerous works have presented techniques for obtaining reduced order models (ROMs) of mistuned bladed disks. Most of these works focus in only one rotor’s stage, though some also include several stages and even the rotor shaft. However, to the authors’ knowledge, the ROM techniques available in the literature consider only one blade geometry by stage, thus making impossible their use for the case of impellers with two or more different blade geometries. This paper shows an adaptation of a previously published reduced order modeling technique in order to allow its application to the case of industrial compressor impellers incorporating two or more different blade geometries (main and splitter blades). The technique is based on Craig and Bampton’s component mode synthesis and it permits to introduce different mistuning patterns for each blade geometry while the disk is considered as a cyclic symmetric structure. The proposed technique is applied to an industrial compressor impeller in order to assess its precision and validity. Generation of finite element parent model for the real compressor via laser scanning is presented and discussed as well as simplifications used in order to generate the impeller’s ROM. Validation is carried out by comparison of predictions for the forced response of the tuned and mistuned impeller, obtained by means of the ROM and the finite element parent model. Results show that the ROM properly represents the dynamic features of the parent model in the frequency range of interest, with minimal computational cost. Furthermore, the ROM properly captures the localization phenomenon when it occurs.

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