FEM SIMULATIONS AND EXPERIMENTAL VALIDATION OF FREQUENCY RESPONSE PREDICTION FOR ACOUSTIC SOUNDBOARDS

2021 ◽  
Author(s):  
L Ausiello ◽  
G Nocoletti
2020 ◽  
Vol 36 (6) ◽  
pp. 867-879
Author(s):  
X. H. Liao ◽  
W. F. Wu ◽  
H. D. Meng ◽  
J. B. Zhao

ABSTRACTTo evaluate the dynamic properties of a coupled structure based on the dynamic properties of its substructures, this paper investigates the dynamic substructuring issue from the perspective of response prediction. The main idea is that the connecting forces at the interface of substructures can be expressed by the unknown coupled structural responses, and the responses can be solved rather easily. Not only rigidly coupled structures but also resiliently coupled structures are investigated. In order to further comprehend and visualize the nature of coupling problems, the Neumann series expansion for a matrix describing the relation between the coupled and uncoupled substructures is also introduced in this paper. Compared with existing response prediction methods, the proposed method does not have to measure any forces, which makes it easier to apply than the others. Clearly, the frequency response function matrix of coupled structures can be derived directly based on the response prediction method. Compared with existing frequency response function synthesis methods, it is more straightforward and comprehensible. Through demonstration of two examples, it is concluded that the proposed method can deal with structural coupling problems very well.


2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Karthik Yerrapragada ◽  
Armaghan Salehian

The experimental study and model validations for the coupled dynamics of a cable-harnessed beam structure are presented. The system under consideration consists of multiple pretensioned cables attached along the length of the host beam structure positioned at an offset distance from the beam centerline. Analytical model presented by the coupled partial differential equations (PDEs) for various coordinates of vibrations is found, and the displacement frequency response functions (FRFs) obtained for both Euler–Bernoulli and Timoshenko-based models are compared to those from the experiments for validation. The results are shown to be in very good agreement with the experiments.


2017 ◽  
Vol 12 (4) ◽  
Author(s):  
Yousheng Chen ◽  
Andreas Linderholt ◽  
Thomas J. S. Abrahamsson

Correlation and calibration using test data are natural ingredients in the process of validating computational models. Model calibration for the important subclass of nonlinear systems which consists of structures dominated by linear behavior with the presence of local nonlinear effects is studied in this work. The experimental validation of a nonlinear model calibration method is conducted using a replica of the École Centrale de Lyon (ECL) nonlinear benchmark test setup. The calibration method is based on the selection of uncertain model parameters and the data that form the calibration metric together with an efficient optimization routine. The parameterization is chosen so that the expected covariances of the parameter estimates are made small. To obtain informative data, the excitation force is designed to be multisinusoidal and the resulting steady-state multiharmonic frequency response data are measured. To shorten the optimization time, plausible starting seed candidates are selected using the Latin hypercube sampling method. The candidate parameter set giving the smallest deviation to the test data is used as a starting point for an iterative search for a calibration solution. The model calibration is conducted by minimizing the deviations between the measured steady-state multiharmonic frequency response data and the analytical counterparts that are calculated using the multiharmonic balance method. The resulting calibrated model's output corresponds well with the measured responses.


2009 ◽  
Vol 33 (1) ◽  
pp. 26-36 ◽  
Author(s):  
S. Filiz ◽  
C.-H. Cheng ◽  
K.B. Powell ◽  
T.L. Schmitz ◽  
O.B. Ozdoganlar

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Patrick Gaiser ◽  
Markus Klingler ◽  
Jürgen Wilde

Abstract Direct bonded copper (DBC) alumina (Al2O3) substrates are used in power electronic devices in order to transfer the heat from semiconductor devices to the heat sink and to carry high electric currents. Fatigue-induced cracks in the ceramic result in a diminished heat dissipation, leading to failure of a power device. Hence, a lifetime model concerning this failure mode is necessary. In this paper, a new lifetime model including crack initiation as well as crack propagation for the fatigue fracture of Al2O3-based DBC substrates is presented. It is based on experimental crack detection techniques and finite element method (FEM) simulations including fracture mechanics. For the validation of the lifetime model, experiments are presented which show that by appropriate design of the copper edge, the lifetime of the substrates is increased substantially.


2007 ◽  
Vol 47 (9) ◽  
pp. 1368-1380 ◽  
Author(s):  
Tony L. Schmitz ◽  
Kevin Powell ◽  
Dongki Won ◽  
G. Scott Duncan ◽  
W. Gregory Sawyer ◽  
...  

2013 ◽  
Vol 69 (5-8) ◽  
pp. 1855-1872 ◽  
Author(s):  
Barbara Reggiani ◽  
Antonio Segatori ◽  
Lorenzo Donati ◽  
Luca Tomesani

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