29 research outputs found
Π‘ΡΡΠ°ΡΠ΅Π³ΠΈΡ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΊΠ»Π°ΡΡΠ΅ΡΠΎΠ² ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠΉ Π² ΠΌΠ΅ΠΆΠΎΡΡΠ°ΡΠ»Π΅Π²ΠΎΠΉ ΡΠ΅Π³ΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎΠΉ ΠΈΠ½ΡΠ΅Π³ΡΠ°ΡΠΈΠΈ
ΠΠ»Π°ΡΡΠ΅ΡΡ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠΉ, ΡΠ΅ΡΡΠΈΡΠΎΡΠΈΠ°Π»ΡΠ½ΡΠΉ ΠΌΠ°ΡΠΊΠ΅ΡΠΈΠ½Π³, ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π» ΡΠ΅Π³ΠΈΠΎΠ½Π°, ΠΌΠ΅ΠΆΠ΄ΡΠ½Π°ΡΠΎΠ΄Π½Π°Ρ ΠΊΠΎΠ½ΠΊΡΡΠ΅Π½ΡΠΎΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡΡ, ΠΈΠ½Π²Π΅ΡΡΠΈΡΠΈΠΈ, Π³ΠΎΡΡΠ΄Π°ΡΡΡΠ²Π΅Π½Π½ΠΎ-ΡΠ°ΡΡΠ½ΠΎΠ΅ ΠΏΠ°ΡΡΠ½Π΅ΡΡΡΠ²ΠΎ, ΡΡΡΠ°ΡΠ΅Π³ΠΈΡ ΡΠ΅Π³ΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠ°Π·Π²ΠΈΡΠΈΡ
Introducing a microstructure-embedded autoencoder approach for reconstructing high-resolution solution field data from a reduced parametric space
In this study, we develop a novel multi-fidelity deep learning approach that
transforms low-fidelity solution maps into high-fidelity ones by incorporating
parametric space information into a standard autoencoder architecture. This
method's integration of parametric space information significantly reduces the
need for training data to effectively predict high-fidelity solutions from
low-fidelity ones. In this study, we examine a two-dimensional steady-state
heat transfer analysis within a highly heterogeneous materials microstructure.
The heat conductivity coefficients for two different materials are condensed
from a 101 x 101 grid to smaller grids. We then solve the boundary value
problem on the coarsest grid using a pre-trained physics-informed neural
operator network known as Finite Operator Learning (FOL). The resulting
low-fidelity solution is subsequently upscaled back to a 101 x 101 grid using a
newly designed enhanced autoencoder. The novelty of the developed enhanced
autoencoder lies in the concatenation of heat conductivity maps of different
resolutions to the decoder segment in distinct steps. Hence the developed
algorithm is named microstructure-embedded autoencoder (MEA). We compare the
MEA outcomes with those from finite element methods, the standard U-Net, and
various other upscaling techniques, including interpolation functions and
feedforward neural networks (FFNN). Our analysis shows that MEA outperforms
these methods in terms of computational efficiency and error on test cases. As
a result, the MEA serves as a potential supplement to neural operator networks,
effectively upscaling low-fidelity solutions to high fidelity while preserving
critical details often lost in traditional upscaling methods, particularly at
sharp interfaces like those seen with interpolation
Comparative analysis of phase-field and intrinsic cohesive zone models for fracture simulations in multiphase materials with interfaces: Investigation of the influence of the microstructure on the fracture properties
This study evaluates four widely used fracture simulation methods, comparing
their computational expenses and implementation complexities within the Finite
Element (FE) framework when employed on heterogeneous solids. Fracture methods
considered encompass the intrinsic Cohesive Zone Model (CZM) using
zero-thickness cohesive interface elements (CIEs), the Standard Phase-Field
Fracture (SPFM) approach, the Cohesive Phase-Field fracture (CPFM) approach,
and an innovative hybrid model. The hybrid approach combines the CPFM fracture
method with the CZM, specifically applying the CZM within the interface zone. A
significant finding from this investigation is that the CPFM method is in
agreement with the hybrid model when the interface zone thickness is not
excessively small. This implies that the CPFM fracture methodology may serve as
a unified fracture approach for multiphase materials, provided the interface
zone's thickness is comparable to that of the other phases. In addition, this
research provides valuable insights that can advance efforts to fine-tune
material microstructures. An investigation of the influence of the interface
material properties, morphological features and spatial arrangement of
inclusions showes a pronounced effect of these parameters on the fracture
toughness of the material
Parametric Model Order Reduction of Guided Ultrasonic Wave Propagation in Fiber Metal Laminates with Damage
This paper focuses on parametric model order reduction (PMOR) of guided ultrasonic wave propagation and its interaction with damage in a fiber metal laminate (FML). Structural health monitoring in FML seeks to detect, localize and characterize the damage with high accuracy and minimal use of sensors. This can be achieved by the inverse problem analysis approach, which employs the signal measurement data recorded by the embedded sensors in the structure. The inverse analysis requires us to solve the forward simulation of the underlying system several thousand times. These simulations are often exorbitantly expensive and trigger the need for improving their computational efficiency. A PMOR approach hinged on the proper orthogonal decomposition method is presented in this paper. An adaptive parameter sampling technique is established with the aid of a surrogate model to efficiently update the reduced-order basis in a greedy fashion. A numerical experiment is conducted to illustrate the parametric training of the reduced-order model. The results show that the reduced-order solution based on the PMOR approach is accurately complying with that of the high fidelity solution
Damage Identification in Fiber Metal Laminates using Bayesian Analysis with Model Order Reduction
Fiber metal laminates (FML) are composite structures consisting of metals and
fiber reinforced plastics (FRP) which have experienced an increasing interest
as the choice of materials in aerospace and automobile industries. Due to a
sophisticated built up of the material, not only the design and production of
such structures is challenging but also its damage detection. This research
work focuses on damage identification in FML with guided ultrasonic waves (GUW)
through an inverse approach based on the Bayesian paradigm. As the Bayesian
inference approach involves multiple queries of the underlying system, a
parameterized reduced-order model (ROM) is used to closely approximate the
solution with considerably less computational cost. The signals measured by the
embedded sensors and the ROM forecasts are employed for the localization and
characterization of damage in FML. In this paper, a Markov Chain Monte-Carlo
(MCMC) based Metropolis-Hastings (MH) algorithm and an Ensemble Kalman
filtering (EnKF) technique are deployed to identify the damage. Numerical tests
illustrate the approaches and the results are compared in regard to accuracy
and efficiency. It is found that both methods are successful in multivariate
characterization of the damage with a high accuracy and were also able to
quantify their associated uncertainties. The EnKF distinguishes itself with the
MCMC-MH algorithm in the matter of computational efficiency. In this
application of identifying the damage, the EnKF is approximately thrice faster
than the MCMC-MH
Experimental determination of Lamb wave dispersion diagrams over large frequency ranges in fiber metal laminates
Fiber metal laminates (FML) are of high interest for lightweight structures
as they combine the advantageous material properties of metals and
fiber-reinforced polymers. However, low-velocity impacts can lead to complex
internal damage. Therefore, structural health monitoring with guided ultrasonic
waves (GUW) is a methodology to identify such damage. Numerical simulations
form the basis for corresponding investigations, but experimental validation of
dispersion diagrams over a wide frequency range is hardly found in the
literature. In this work the dispersive relation of GUWs is experimentally
determined for an FML made of carbon fiber-reinforced polymer and steel. For
this purpose, multi-frequency excitation signals are used to generate GUWs and
the resulting wave field is measured via laser scanning vibrometry. The data
are processed by means of a non-uniform discrete 2d Fourier transform and
analyzed in the frequency-wavenumber domain. The experimental data are in
excellent agreement with data from a numerical solution of the analytical
framework. In conclusion, this work presents a highly automatable method to
experimentally determine dispersion diagrams of GUWs in FML over large
frequency ranges with high accuracy