Low-velocity impact damage is a major concern in the design of structures made of advanced laminated composites, because such damage is mostly hidden inside the laminates and cannot be detected by visual inspection. It is necessary to develop the impact monitoring techniques providing on-line diagnostics of smart composite structures susceptible to impacts. In this paper, we discuss the process for impact location detection in which the generated acoustic signals are detected by PZT using the improved neural network paradigms. To improve the accuracy and reliability of a neural network based impact identification method, the Levenberg-Marquardt algorithm and the generalization methods were applied. This study concentrates not only on the determination of the location of impacts from sensor data, but also the implementation of time-frequency analysis such as the Wavelet Transform (WT) to measure the characteristic frequencies of acoustic emission waves for the determination of the occurrence and the estimation of impact damage.

신경회로망과 웨이블릿 변환을 이용한 스마트 복합적층판의 충격 모니터링 연구 = Impact monitoring of smart composite laminates using neural networks and wavelet analysis

Fitness–Distance Balance based adaptive guided differential evolution algorithm for security-constrained optimal power flow problem incorporating renewable energy sources

A novel discrete bat algorithm for heterogeneous redundancy allocation of multi-state systems subject to probabilistic common-cause failure

In this paper, a novel Cauchy-Gaussian quantum-behaved bat algorithm (CGQBA) is applied to solve the economic load dispatch (ELD) problem. The bat algorithm (BA) is an acknowledged metaheuristic optimization algorithm owing to its performance. However, the classical BA presents some weaknesses, such as premature convergence. To withstand the drawbacks of the BA, quantum mechanics theories and Gaussian and Cauchy operators are integrated into the standard BA to enhance its effectiveness. Since the economic load dispatch is a nonlinear, complex and constrained optimization problem, its main objective is to reduce the total generation cost while matching the equality and inequality constraints of the system. The validity of the CGQBA is tested on six standard benchmark functions with different characteristics. The numerical results indicate that the CGQBA is effective and superior to many other algorithms. Moreover, the CGQBA is applied to solve the ELD problems on various test systems including 3,6,20, 40,110 and 160 implemented generating units. The simulation results illustrate the strength of the CGQBA compared with other algorithms recently reported in the literature.

A Cauchy-Gaussian Quantum-Behaved Bat Algorithm Applied to Solve the Economic Load Dispatch Problem

Impact identification of composite cylinder based on improved deep metric learning model and weighted fusion Tikhonov regularized total least squares

A novel bat algorithm with double mutation operators and its application to low-velocity impact localization problem

A hybrid support vector regression with multi-domain features for low-velocity impact localization on composite plate structure

For the nondestructive testing based on ultrasonic Lamb waves, the center frequency of the excitation signal should be appropriately selected to excite the specific Lamb wave mode in composite laminates according to the dispersion curves. However, it is difficult to achieve the dispersion curves of Lamb waves in composite laminates by using analytical methods. In this paper, the three-dimensional finite element model with the anti-symmetric surface excitation is established to analyze the dispersion characteristics of Lamb wave propagation in a composite laminate. The fundamental anti-symmetric (A0) Lamb wave mode is excited in the composite laminate by applying a concentrated force load and an anti-symmetric concentrated force load. The characteristics of Lamb wave propagation in the composite laminate are studied. Moreover, the group velocities of the A0 Lamb wave mode propagating in the composite laminate are calculated under the excitation signals with twelve different center frequencies. The group velocity dispersion curve of the A0 Lamb wave mode obtained by the established model is consistent with that of the guided wave software GUIGUW, which demonstrates the effectiveness and feasibility of the three-dimensional finite element model on analyzing the dispersion characteristics of Lamb wave propagation in the composite laminate.

Jindong Li

Papers

A novel bat algorithm with double mutation operators and its application to low-velocity impact localization problem

A hybrid support vector regression with multi-domain features for low-velocity impact localization on composite plate structure

Numerical Simulation for Dispersion Characteristics of Lamb Wave Propagation in Composite Laminates with Anti-Symmetric Surface Excitation