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Biomedical subjects

Jianchun Cheng

Publications and source records attributed to Jianchun Cheng.

2 recordsLinked to original sources

Contact acoustic nonlinearity in a bonded solid-solid interface.

We have conducted research on the contact acoustic nonlinearity (CAN) produced by a bonded solid-solid interface in order to find a nondestructive and quantitative method to evaluate the bonding strength of the interface. A CAN model is used to depict a bonded state from the relationship between the CAN parameter and the bonding strength and the crack width in the interface. According to this model, a nondestructive evaluation of the bonding strength can be established. When the CAN parameter and the crack width are measured, the bonding strength can be calculated from the model. In this paper, the bonding strengths of some samples are evaluated based on the CAN method. The results well agree with the bonding strengths measured by hanging clogs (weights) to destroy their interfaces.

Journal Article↗

Determination of the elastic constants of a composite plate using wavelet transforms and neural networks.

An inverse method based on a combination of the wavelet transform and artificial neural networks is presented. The method is used to recover the elastic constants of a fiber-reinforced composite plate from experimental measurements of ultrasonic Lamb waves generated and detected with lasers. In this method, the elastic constants are not recovered from the dispersion curves but rather directly from the measured waveforms. Transient waveforms obtained by numerical simulations for different elastic constants are used as input to train the neural network. The wavelet transform is used to extract the eigenvectors from the Lamb wave signals to simplify the structure of the neutral network. The eigenvectors are then introduced into a multilayer internally recurrent neural network with a back-propagation algorithm. Finally, experimental waveforms recoded on a titanium-graphite composite plate are used as input to recover the elastic constants of the material.

Journal Article↗