Papers by Keyword: Cracked Plate

Abstract: In this paper a numerical modeling was carried out to study the problem of plane elasticity in a medium cracked by the method of the extended finite elements (XFEM) in a thin cracked plate made of aluminum using the software Abaqus 6.13.This method improved the capability of the classical finite element method especially the crack propagation problems. Furthermore, the extended finite elements method has been used to simulate tensile and fracture behavior of the study materials. Based on variation in size and shape of crack, the results obtained will be compared with those obtained experimentally, this comparison shows a good agreement.

Abstract: The behavior of a center-cracked aluminum plate repaired with carbon-fiber wrapped composite material under axial loading is investigated. The carbon-fiber wrapped composite material is simulated as transversely isotropic material by means of an equivalent modulus method. The repair patch is applied on one side of the cracked plate. The stress intensity factors along the crack front and the stress distribution at the repair domain are examined. The numerical simulation results indicate that the carbon-fiber wrapped composite material performs very well in the repair to cracked plate and an appropriate thickness of the repair patch needs to be selected.

Abstract: Aiming at the defects in describing stress field near the crack tip with traditional finite element method (TFEM), a new finite element method based on interval B-Spline wavelet (IBSW) is put forward, the displacement interpolation functions of plate element are constructed by using the scaling functions of IBSW, finite element model of cracked plate based on IBSW is established, and the stiffness matrixes of plate element is derived. The first four natural frequencies and mode shapes of the cracked plate are obtained by using interval B-Spline wavelet finite element (IBSWFE). Comparison of the calculated results with those by ANSYS shows that IBSWFE method can get higher calculation precision with less elements in dealing with engineering singularity problems.

Abstract: A practical method to evaluate the thermal shock stress intensity factors (TS-SIF`s) associated with a flexibly restrained edge-cracked plate (FRECP) is outlined. It is assumed that the edge crack can be represented with a spring couple, and the deformations of the edge-cracked plate are consistent with Euler-Bernoulli deformation theory. It is then demonstrated how a compliance analysis of this simplified representation can be used with a finite element analysis of equivalent crack free plates to evaluate to TS-SIF`s associated with a FRECP. The accuracy of this method is shown to be excellent by comparing it against a direct fracture mechanic finite element analysis. This method is therefore advantageous to a fracture mechanic finite element analysis as it does not require an explicit analysis of a FRECP.

Abstract: Two practical methods have been used to estimate thermal shock stress intensity factors (TS-SIF`s) associated with a flexibly restrained cracked plate. The first method used a traditional mechanical weight function (MWF) methodology in conjunction with the MWF derived for an equivalent freely restrained cracked component. The second method used a traditional MWF methodology in conjunction with the MWF derived for an equivalent rigidly restrained cracked component. Fracture mechanic finite element analyses were also undertaken to construct a comparative benchmark for the TS-SIF`s associated with a flexibly restrained cracked plate. The results of this comparison demonstrate the errors associated with these MWF methods to be acceptable, if and only if, the crack size is small, the crack component aspect ratio is large or the flexible boundary restraint stiffness are deemed negligible or near rigid. In addition, the curves derived with these MWF methods do not intersect and there is no obvious transition to distinguish which MWF method would be more appropriate for a given a particular flexible boundary restraint configuration. In effect, this means that these MWF methods cannot be confidently used to evaluate the TS-SIF`s associated with a flexibly restrained cracked component.

Abstract: This paper investigates the sound power radiated from a cracked plate. The sound power is obtained by using a lumped parameters model-based acoustics theory and vibration responses obtained by using the finite element method. It is shown that the vibration mode shapes and crack angle are closely related to the sound radiation characteristics, which can be applied to detect damages such as the cracks generated within a structure.