scholarly journals Evaluating the Reduction of Stress Intensity Factor in Center-Cracked Plates Using Piezoelectric Actuators

Actuators ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 25
Author(s):  
Ahmed Abuzaid ◽  
Meftah Hrairi ◽  
Mohd Dawood
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Piezoelectric Actuators ◽  
Cracked Plates

Modeling approach to evaluating reduction in stress intensity factor in center-cracked plate with piezoelectric actuator patches

2016 ◽  
Vol 28 (10) ◽  
pp. 1334-1345 ◽  
Author(s):  
Ahmed Abuzaid ◽  
Meftah Hrairi ◽  
MSI Shaik Dawood
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Piezoelectric Actuator ◽  
Piezoelectric Actuators ◽  
Mode I ◽  
Damage Propagation ◽  
Piezoelectric Patch ◽  
Cracked Structure

Active repairs using piezoelectric actuators can play a significant role in reducing the crack damage propagation in thin plate structures. Mode-I crack opening displacement is the most predominant one in tension, and it is responsible for the failure which in turn affects the load carrying capability of the cracked structure. In addition, there are limited studies that investigated the effect of the piezoelectric actuator over mode-I active repair. In this study, the mode-I stress intensity factor for a plate with a center crack, and a bonded piezoelectric actuator was modeled using the linear elastic fracture mechanics. For this, an analytical closed-form solution is developed using the virtual crack closure technique taking into account mode-I as the only effective mode, coupling effects of the piezoelectric patch, and the singular stress at the crack tip. In addition, the total stress intensity factor was obtained by the superposition of the stress intensity factor obtained from the stresses produced by the piezoelectric actuators on the crack surfaces as the only external loads on the cracked plate and the stress intensity factor due to the far-field tension load. The proposed analytical model for mode-I stress intensity factor was verified by a finite element–based approach using ANSYS finite element software. The results demonstrated a good agreement between the analytical and finite element models with a relative error of less than 4% in all the cases studied. The results illustrated that the piezoelectric patch is efficient in reducing stress intensity factor when an extension mode of the actuator is applied. However, applying a contraction mode of the piezoelectric actuators produced negative strain which increased the stress intensity factor and thus the severity of the cracked structure and could lead to damage propagation.

scholarly journals Evaluation of Stress Intensity Factor of Cracked Plates

2021 ◽  
Vol 9 (VII) ◽  
pp. 1994-1998
Author(s):  
Reshma C
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Intensity Factor ◽  
Factor Of Safety ◽  
Analytical Determination ◽  
Rectangular Plates ◽  
Cracked Plates ◽  
Heavy Loads ◽  
As Stress

Structures are subjected to undesirable changes in their structural properties mainly due to errors in design and construction, heavy loads, fatigue or other degradation. Plate structures are highly sensitive to the formation of cracks and its growth which adversely affects its performance. Notches, induced or self occurring defects, holes acts as stress concentration zone which initiates the crack formation. Knowledge about the severity of cracks is important to predict the component’s life. According to linear elastic fracture mechanics, a key parameter in determining the crack severity is stress intensity factor. Years ago , high factor of safety was chosen to account for unforeseen factors. Development of fracture mechanics enables a designer to use a lower factor of safety, thereby reducing structural components cost. The components weight is also reduced and their reliability is thus enhanced. In this work, experimental and analytical determination of combination of stress intensity factors for rectangular plates with inclined through crack subjected to uniaxial load at failure is found out.

A Comparison of Stress Intensity Factor Solutions for Surface Cracked Plates

2020 ◽  
Author(s):  
C. J. Aird
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Structural Integrity ◽  
Surface Cracks ◽  
Surface Point ◽  
Function Solution ◽  
Cracked Plates ◽  
Extended Surface ◽  
Definition Of

Abstract The present paper compares the stress intensity factor (SIF) solutions for surface-cracked plates presented in R6, BS 7910, API 579-1/ASME FFS-1 and RSE-M. Both extended surface cracks and semi-elliptical surface cracks are considered. In general, the agreement between the various solutions is found to be good at within 5%. However, particular cases are highlighted which are associated with larger differences between the SIFs. For extended surface cracks, the various solutions agree closely at within 5% in all but one case. For semi-elliptical surface cracks, the agreement between the various solutions is generally better at the deepest point than at the so-called ‘surface’ points. In particular, the surface point SIFs corresponding to the Vainshtok and Varfolomeyev weight function solution which appears in API-579-1/ASME FFS-1 differ significantly from the other solutions in some cases. It is concluded that further work is required in order to establish an appropriate definition of the surface point SIF for use in structural integrity calculations.

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