Fatigue crack growth analysis using Bootstrap S-version finite element model

2020 ◽  
Vol 42 (4) ◽  
Author(s):  
M. N. M. Husnain ◽  
M. R. M. Akramin ◽  
Z. L. Chuan ◽  
Akiyuki Takahashi
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Finite Element Model ◽  
Crack Growth ◽  
Growth Analysis ◽  
Element Model

A research on fatigue crack growth monitoring based on multi-sensor and data fusion

2019 ◽  
pp. 147592171986572
Author(s):  
Chang Qi ◽  
Yang Weixi ◽  
Liu Jun ◽  
Gao Heming ◽  
Meng Yao
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Data Fusion ◽  
Crack Propagation ◽  
Finite Element Model ◽  
Crack Length ◽  
Crack Growth ◽  
Lamb Wave ◽  
Element Model

Fatigue crack propagation is one of the main problems in structural health monitoring. For the safety and operability of the metal structure, it is necessary to monitor the fatigue crack growth process of the structure in real time. In order to more accurately monitor the expansion of fatigue cracks, two kinds of sensors are used in this article: strain gauges and piezoelectric transducers. A model-based inverse finite element model algorithm is proposed to perform pattern recognition of fatigue crack length, and the fatigue crack monitoring experiment is carried out to verify the algorithm. The strain spectra of the specimen under cyclic load in the simulation and experimental crack propagation are obtained, respectively. The active lamb wave technique is also used to monitor the crack propagation. The relationship between the crack length and the lamb wave characteristic parameter is established. In order to improve the recognition accuracy of the crack propagation mode, the random forest and inverse finite element model algorithms are used to identify the crack length, and the Dempster–Shafer evidence theory is used as data fusion to integrate the conclusion of the two algorithms to make a more accountable and correct judge of the crack length. An experiment has been conducted to demonstrate the effectiveness of the method.

Fatigue Crack Growth Analysis on a Rotor Blade Under Forced Response

2013 ◽  
Author(s):  
B. Dompierre ◽  
E. Wyart ◽  
M. Mesbah ◽  
F. Thirifay
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Rotor Blade ◽  
Growth Analysis ◽  
Mechanical Stability ◽  
Forced Response ◽  
Dynamics Simulation ◽  
Fe Model

This paper focuses on the fatigue crack growth resulting from an aeroelastic behavior of a fan blade when operating under upstream distortion. The forced response of the first bending mode of the blade due to the inlet distortion is analyzed and the mechanical stability of blades is investigated. The forced response of one blade is evaluated using an uncoupled approach. In this approach, the forced response is calculated in four steps. First, the modal analysis is obtained using Finite Element (FE) calculations. In the second step, the aerodynamic damping is obtained by performing the CFD (Computational Fluid Dynamics) simulation for a single rotor blade with a prescribed harmonic forced motion. The next step is the estimation of the excitation forces when the unsteadiness of the inlet flow has a frequency close to the eigenfrequency of the blade. In the end, by solving the equations of equilibrium forces of the structure, the forced response is computed. Afterwards, a fatigue crack growth analysis is performed. The crack is assumed to initiate in the area of the maximum principal stress. The crack is inserted into the FE model using the Extended Finite Element Method (XFEM) [1, 2] which is implemented in an in-house plugin “Morfeo-crack” for Samcef (commercial finite element analysis software package). This method allows for easily inserting a crack while minimizing the difficulties inherent to the mesh adaptation since the crack does not need to be explicitly meshed. The calculations are performed under the Linear Elastic Fracture Mechanics hypothesis. Finally, the crack path as well as the lifespan are estimated.

Fatigue Crack Growth Analysis of Interface Between Lead Frame and Molding Compound

2018 ◽  
Author(s):  
Erkan Bektas ◽  
Katrin Broermann ◽  
Sascha P. Brumm ◽  
Goran Pecanac ◽  
Sven Rzepka ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Analysis ◽  
Lead Frame ◽  
Molding Compound

Finite Element Simulation of Stable Fatigue Crack Growth Using Critical CTOD Determined by Preliminary Finite Element Analysis

2014 ◽  
Vol 891-892 ◽  
pp. 1675-1680
Author(s):  
Seok Jae Chu ◽  
Cong Hao Liu
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Finite Element Simulation ◽  
Crack Growth ◽  
Crack Tip ◽  
Stress Intensity Factor Range ◽  
Crack Tip Opening Displacement ◽  
Element Analysis ◽  
Element Simulation

Finite element simulation of stable fatigue crack growth using critical crack tip opening displacement (CTOD) was done. In the preliminary finite element simulation without crack growth, the critical CTOD was determined by monitoring the ratio between the displacement increments at the nodes above the crack tip and behind the crack tip in the neighborhood of the crack tip. The critical CTOD was determined as the vertical displacement at the node on the crack surface just behind the crack tip at the maximum ratio. In the main finite element simulation with crack growth, the crack growth rate with respect to the effective stress intensity factor range considering crack closure yielded more consistent result. The exponents m in the Paris law were determined.

Finite element model for crack growth process in concrete bituminous

2012 ◽  
Vol 44 (1) ◽  
pp. 35-43 ◽  
Author(s):  
F. Dubois ◽  
R. Moutou-Pitti ◽  
B. Picoux ◽  
C. Petit
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Crack Growth ◽  
Growth Process ◽  
Element Model ◽  
Crack Growth Process
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