Modal Identification in an Automotive Multi-Component System Using HS 3D-DIC

Molina-Viedma, Ángel J.; López‐Alba, Elías; Felipe-Sesé, Luis; Díaz, Francisco

doi:10.3390/ma11020241

Cited by 12 publications

(3 citation statements)

References 27 publications

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“…The impact force was assumed to be the unknown excitation force and the measured response of the test structure was used to compute the ODS FRF and to construct the ODS [ 79 ]. This new type of measurement is called ODS FRF measurement [ 33 , 69 , 78 ] or transmissibility measurement [ 77 , 80 ]. If the ODS at or near a resonant frequency would be dominated by a single corresponding mode shape at that resonant frequency, then the ODS could be approximate to the mode shape [ 63 , 66 , 78 ].…”

Section: Methodsmentioning

confidence: 99%

Dynamic Characteristics and Damage Detection of a Metallic Thermal Protection System Panel Using a Three-Dimensional Point Tracking Method and a Modal Assurance Criterion

Goo

2020

Sensors

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A thermal protection system (TPS) is designed and fabricated to protect a hypersonic vehicle from extreme conditions. Good condition of the TPS panels is necessary for the next flight mission. A loose bolted joint is a crucial defect in a metallic TPS panel. This study introduces an experimental method to investigate the dynamic characteristics and state of health of a metallic TPS panel through an operational modal analysis (OMA). Experimental investigations were implemented under free-free supports to account for a healthy state, the insulation effect, and fastener failures. The dynamic deformations resulted from an impulse force were measured using a non-contact three-dimensional point tracking (3DPT) method. Using changes in natural frequencies, the damping ratio, and operational deflection shapes (ODSs) due to the TPS failure, we were able to detect loose bolted joints. Moreover, we also developed an in-house program based on a modal assurance criterion (MAC) to detect the state of damage of test structures. In a damage state, such as a loose bolted joint, the stiffness of the TPS panel was reduced, which resulted in changes in the natural frequency and the damping ratio. The calculated MAC values were less than one, which pointed out possible damage in the test TPS panels. Our results also demonstrated that a combination of the 3DPT-based OMA method and the MAC achieved good robustness and sufficient accuracy in damage identification for complex aerospace structures such as TPS structures.

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Section: Methodsmentioning

confidence: 99%

Dynamic Characteristics and Damage Detection of a Metallic Thermal Protection System Panel Using a Three-Dimensional Point Tracking Method and a Modal Assurance Criterion

Goo

2020

Sensors

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“…In addition, some relevant functions are offered to complete a modal analysis: operations in the FRF, FRF generation from mass, damping and stiffness matrices, MAC and modal collinearity [33]. Therefore, the estimation of modal parameters was performed with EasyMod due to its practicality and accuracy, as presented in [34][35][36]. A complete EasyMod user-guide is available in the following reference [33].…”

Section: Modal Parameter Extractionmentioning

confidence: 99%

Experimental Modal Analysis of an Aircraft Wing Prototype for SAE Aerodesign Competition

Gasparetto

Machado

Carneiro

2020

DYNA

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This work presents an experimental modal analysis of an aircraft wing prototype, designed by the Aerodesign team of the University of Brasilia, and performs a ground vibration testing of the prototype. The dynamic response data were acquired using the software LabVIEW, and the modal parameters were identified through the EasyMod toolbox. The modal parameters are characterised for the first seven vibration modes of the structure, with the firsts two being suspension modes of vibration. The effect of small changes in the experimental procedure on the identified modal parameters is discussed. It was observed that the use of an excitation signal as a logarithmic sine sweep and with a frequency range of excitation between 2 to 150 Hz resulted in less noise and more accurate measurement of the structure’s response. Results for different modal identification methods were verified using the Modal Assurance Criterion (MAC), and good correlation was achieved.

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“…An aleatory speckle pattern on the specimen surface is required (black dots randomly distributed on white background). This technique has multiple applications in experimental mechanics, either for static or high speed testing [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Its sensitivity strongly depends on the resolution of the camera and the optical arrangement, resulting in a range from microns to centimetres.…”

Section: Introductionmentioning

confidence: 99%

RGB Colour Encoding Improvement for Three-Dimensional Shapes and Displacement Measurement Using the Integration of Fringe Projection and Digital Image Correlation

Felipe-Sesé

Molina-Viedma

López‐Alba

et al. 2018

Sensors

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Three-dimensional digital image correlation (3D-DIC) has become the most popular full-field optical technique for measuring 3D shapes and displacements in experimental mechanics. The integration of fringe projection (FP) and two-dimensional digital image correlation (FP + DIC) has been recently established as an intelligent low-cost alternative to 3D-DIC, overcoming the drawbacks of a stereoscopic system. Its experimentation is based on the colour encoding of the characterized fringe and speckle patterns required for FP and DIC implementation, respectively. In the present work, innovations in experimentation using FP + DIC for more accurate results are presented. Specifically, they are based on the improvement of the colour pattern encoding. To achieve this, in this work, a multisensor camera and/or laser structural illumination were employed. Both alternatives are analysed and evaluated. Results show that improvements both in three-dimensional and in-plane displacement are obtained with the proposed alternatives. Nonetheless, multisensor high-speed cameras are uncommon, and laser structural illumination is established as an important improvement when low uncertainty is required for 2D-displacement measurement. Hence, the uncertainty has been demonstrated to be reduced by up to 50% compared with results obtained in previous experimental approaches of FP + DIC.

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Modal Identification in an Automotive Multi-Component System Using HS 3D-DIC

Cited by 12 publications

References 27 publications

Dynamic Characteristics and Damage Detection of a Metallic Thermal Protection System Panel Using a Three-Dimensional Point Tracking Method and a Modal Assurance Criterion

Dynamic Characteristics and Damage Detection of a Metallic Thermal Protection System Panel Using a Three-Dimensional Point Tracking Method and a Modal Assurance Criterion

Experimental Modal Analysis of an Aircraft Wing Prototype for SAE Aerodesign Competition

RGB Colour Encoding Improvement for Three-Dimensional Shapes and Displacement Measurement Using the Integration of Fringe Projection and Digital Image Correlation

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