Piezoelectric coupled LISA for guided wave generation and propagation

2015

SPIE Proceedings

Self Cite

This paper presents a hybrid modeling technique for the efficient simulation of guided wave propagation and interaction with damage in composite structures. This hybrid approach uses a local finite element model (FEM) to compute the excitability of guided waves generated by piezoelectric transducers, while the global domain wave propagation, wavedamage interaction, and boundary reflections are modeled with the local interaction simulation approach (LISA).A small-size multi-physics FEM with non-reflective boundaries (NRB) was built to obtain the excitability information of guided waves generated by the transmitter. Frequency-domain harmonic analysis was carried out to obtain the solution for all the frequencies of interest. Fourier and inverse Fourier transform and frequency domain convolution techniques are used to obtain the time domain 3-D displacement field underneath the transmitter under an arbitrary excitation. This 3-D displacement field is then fed into the highly efficient time domain LISA simulation module to compute guided wave propagation, interaction with damage, and reflections at structural boundaries. The damping effect of composite materials was considered in the modified LISA formulation. The grids for complex structures were generated using commercial FEM preprocessors and converted to LISA connectivity format. Parallelization of the global LISA solution was achieved through Compute Unified Design Architecture (CUDA) running on Graphical Processing Unit (GPU). The multi-physics local FEM can reliably capture the detailed dimensions and local dynamics of the piezoelectric transducers. The global domain LISA can accurately solve the 3-D elastodynamic wave equations in a highly efficient manner. By combining the local FEM with global LISA, the efficient and accurate simulation of guided wave structural health monitoring procedure is achieved. Two numerical case studies are presented: (1) wave propagation in a unidirectional CFRP composite plate;(2) wave propagation in a stiffened cross-ply CFRP plate with delamination.

Section: Introductionmentioning

confidence: 99%

Hybrid local FEM/global LISA modeling of guided wave propagation and interaction with damage in composite structures

Shen

2015

SPIE Proceedings

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“…With the pin force excitation assumption, the hybrid GMM/LISA method, however, still cannot capture the local dynamics of the transducers. Nadella and Cesnik integrated piezoelectric coupled field capability in LISA [27,28]. This piezo-coupled LISA can accurately simulate the piezoelectric effects and local dynamics of finite dimensional transducers.…”

Section: Introductionmentioning

confidence: 99%

Hybrid local FEM/global LISA modeling of damped guided wave propagation in complex composite structures

Shen

2016

Smart Mater. Struct.

This paper presents a new hybrid modeling technique for the efficient simulation of guided wave generation, propagation, and interaction with damage in complex composite structures. A local finite element model is deployed to capture the piezoelectric effects and actuation dynamics of the transmitter, while the global domain wave propagation and interaction with structural complexity (structure features and damage) are solved utilizing a local interaction simulation approach (LISA). This hybrid approach allows the accurate modeling of the local dynamics of the transducers and keeping the LISA formulation in an explicit format, which facilitates its readiness for parallel computing. The global LISA framework was extended through the 3D Kelvin-Voigt viscoelasticity theory to include anisotropic damping effects for composite structures, as an improvement over the existing LISA formulation. The global LISA framework was implemented using the compute unified device architecture running on graphic processing units. A commercial preprocessor is integrated seamlessly with the computational framework for grid generation and material property allocation to handle complex structures. The excitability and damping effects are successfully captured by this hybrid model, with experimental validation using the scanning laser doppler vibrometry. To demonstrate the capability of our hybrid approach for complex structures, guided wave propagation and interaction with a delamination in a composite panel with stiffeners is presented.

Hybrid Global Matrix/Local Interaction Simulation Approach for Wave Propagation Simulation in Composite Laminates

Obenchain

Nadella

54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

2013

Self Cite

This paper presents a hybrid approach to model guided wave propagation in composite laminates. The global matrix approach is used to determine the displacement field surrounding a piezoelectric actuator. The displacement field is then enforced in a specified region of a numerical model that employs the local interaction simulation approach (LISA). This LISA Hybrid approach circumvents the problem of modeling non-rectangular actuators in the Cartesian discretization in LISA by using the global matrix method to characterize the actuator's influence on a cut-out region surrounding it. Results show the LISA Hybrid model outperforms previous LISA models that enforce in-plane displacements on the surface of the plate. The LISA Hybrid model produces wave propagation time histories that closely match the baseline global matrix method and successfully capture directional effects resulting from the anisotropic nature of composite plates. Results for aluminum, cross-ply, unidirectional, and quasi-isotropic plates show dependence on the in-plane discretization size, but that dependence is less pronounced for the cross-ply case.