The present study utilizes an analytical method to formulate the three lowest modal frequencies of axially-loaded notched beam through both crack location and load level in a specific format that can be used in existing frequency-based crack-identification methods. The proposed formula provides a basis to shift into two states, one with axial loading and the other without any loading whatsoever...

With the characteristics of ANN’s strong capability on nonlinear approximation, a new method by combining an artificial neural network with back-propagation learning algorithm and modal analysis via finite element model of cracked rotor system is proposed for fast identification of crack fault with high accuracy in rotating machinery. First, based on fracture mechanics and the energy principle ...

Experimentally determined T ε and CTOA resistance curves were used to simulate numerically, stable crack growth and the ensuing crack linkup in 0.8 mm thick 2024-T3 aluminum tension specimen with multiple site damage (MSD) subjected to monotonically/cyclically increasing loading. The T ε integral correctly predicted the crack growth and linkup history as well as the onset of rapid fracture in M...

Kriging surrogate model provides explicit functions to represent the relationships between the inputs and outputs of a linear or nonlinear system, which is a desirable advantage for response estimation and parameter identification in structural design and model updating problem. However, little research has been carried out in applying Kriging model to crack identification. In this work, a sche...

Crack identification is a very important issue in mechanical systems, because it is a damage that if develops may cause catastrophic failure. In the first part of this research, modal analysis of a multi-cracked variable cross-section beam is done using finite element method. Then, the obtained results are validated usingthe results of experimental modal analysis tests. In the next part, a nove...

We present a mechanistically faithful and mathematically sound approach to the numerical simulation of secondary thermal cracks propagation in EGS based on the variational approach to fracture [1-4]. While remaining compatible with classical theories, this approach provides a unified framework to crack nucleation, full path identification, including interaction between multiple cracks, branchin...

The present paper deals with the mixed mode fracture analysis of a weakened orthotropic half-plane with multiple cracks propagation. The orthotropic half-plane contains Volterra type glide and climb edge dislocations. It is assumed that the medium is under in-plane loading conditions. The distributed dislocation technique is used to obtain integral equations for the dynamic problem of multiple ...

A laser ultrasonic system is a non-contact inspection device with a long stand-off distance and it is applicable to hard-to-access locations such as in a nuclear power plant. In this paper, multiple surface waves generated by line-shaped multiple pulse laser beams are adopted to precisely detect a surface-breaking crack with its depth information. When a surface crack is positioned at the cente...