Wyniki wyszukiwania - BazTech

1

Residual life estimation of structural beam using experimental and numerical modal analysis methods

Siva Gandam Anand, Ramakrishna Shinigam

Journal of Mechanical and Energy Engineering

|

2020

|

Vol. 4, No 2

135--146

EN

A structural beam is a common element in many mechanical structures such as ship propeller shaft, crane boom, and aircraft wings. In the present paper experimental and numerical modal analysis are carried out for estimating the damage, geometric location of the damage, severity of damage and residual life of structural beam to prevent unexpected failures of mechanical structures. Experimental and numerical modal analysis results for healthy and cracked beam are compared for validation of numerical methodology used in the present paper. Experimental modal analysis is performed on both healthy and cracked beam with the help of impact hammer, acceleration sensor and FFT (Fast Fourier Transformer) analyzer associated with EDM (Engineering Data Management) software. Modal tests are conducted using impact method on selected locations of the entire healthy and cracked beam to find the first three natural frequencies, which are used to detect the presence of damage and geometric location of the damage. Three parametric studies are carried out to know the effect of crack depth, crack location and crack orientation on the natural frequencies of the cracked beam. Finally, the residual life of a healthy and cracked beam was estimated using Basiquin’s equation and finite element analysis software called ANSYS 18.1.

2

Residual life estimation of healthy and cracked composite beam using experimental and numerical modal analysis methods

Ramprasad Gedela, Ramakrishna Shinigam

Journal of Mechanical and Energy Engineering

|

2020

|

Vol. 4, No 2

127--134

EN

Preventive maintenance is beneficial to minimize unexpected breakdowns in industries with continuous production. Composite structures are used for naval applications like ship hulls and marine propellers. In most of the industries, composite structural health analysis using experimental and numerical model are available for damage detection and estimate the residual life of composite beams. The present work is focusses on identification of damage and estimate residual life of composite healthy and cracked beams. Free vibrational analysis is carried out on composite beam made of Glass fiber reinforced polymer (GFRP) with a different crack orientation. A Fast Fourier Transform (FFT) spectrum analyzer associated with engineering data management (EDM) software utilized for experimental analysis to detect presence of damage in cracked composite beam. Finite element method (FEM) software called Analysis of composite pre/post (ACP) available in ANSYS R3 is used to compare the natural frequency results of healthy composite beam with cracked composite beam with different ply orientations. For validation of numerical modal evaluation, the consequences acquired from ANSYS R3 Finite element analysis (FEA) software are in comparison with experimental results received by impact hammer method. The fatigue life of a damaged composite beam is estimated the use of “Hwang and Han’s” fatigue life equation.

3

Structural damage detection in moving load problem using JRNNs based method

Jena Shakti P., Parhi Dayal R.

Journal of Theoretical and Applied Mechanics

|

2019

|

Vol. 57 nr 3

665--676

EN

Damage detection in a structure using the vibration signature is a quiet smart method for condition monitoring of the structure. In this problem, the Recurrent Neural Networks (RNNs) based method has been implemented for damage detection in the moving load problem as an inverse method. A multi-cracked simply supported beam under a traversing load has been considered for the present problem. The localization and severities of the supervised cracks on the structure are determined using the adapted Jordan’s Recurrent Neural Networks (JRNNs) approach. The mechanism of Levenberg-Marquardt’s back propagation algorithm has been implemented to train the networks. To check the adoptability of the proposed JRNNs method, numerical analyses along with laboratory test verifications have been conducted and found to be well emerged.