Data Mining Practical Machine Learning Tools and Techniques

Artificial intelligence for fault diagnosis of rotating machinery: A review

Applications of machine learning to machine fault diagnosis: A review and roadmap

Wavelets for fault diagnosis of rotary machines: A review with applications

Intelligent fault diagnosis techniques have replaced time-consuming and unreliable human analysis, increasing the efficiency of fault diagnosis. Deep learning models can improve the accuracy of intelligent fault diagnosis with the help of their multilayer nonlinear mapping ability. This paper proposes a novel method named Deep Convolutional Neural Networks with Wide First-layer Kernels (WDCNN). The proposed method uses raw vibration signals as input (data augmentation is used to generate more inputs), and uses the wide kernels in the first convolutional layer for extracting features and suppressing high frequency noise. Small convolutional kernels in the preceding layers are used for multilayer nonlinear mapping. AdaBN is implemented to improve the domain adaptation ability of the model. The proposed model addresses the problem that currently, the accuracy of CNN applied to fault diagnosis is not very high. WDCNN can not only achieve 100% classification accuracy on normal signals, but also outperform the state-of-the-art DNN model which is based on frequency features under different working load and noisy environment conditions.

A New Deep Learning Model for Fault Diagnosis with Good Anti-Noise and Domain Adaptation Ability on Raw Vibration Signals

This paper is presented to analyze the sandwich plates with honeycomb core and FGM face sheets for free vibration responses. The equations of motions are derived using Hamilton’s principle and solved using Navier’s method for simply supported sandwich plate. The special type of honeycomb structure known as “auxetic materials” with negative Poisson’s ratio provides excellent resistance to dynamic excitations. The material property of face sheets is graded in the thickness direction using simple power law (P-FGM). Furthermore, parametric studies are performed to analyze the combined effect of span-to-thickness ratio, volume fraction exponent, aspect ratio and geometric parameters of honeycomb structure on fundamental frequency for sandwich P-FGM plates. The results for the soft homogenous core are validated with the previous studies on sandwich plate. It is observed that the fundamental frequency always increases with a decrease in modulus of angle. In addition, due to the presence of honeycomb core in a sandwich plate, unexpected change may occur with the change in geometric parameters.

Free Vibration Analysis of Sandwich Plate with Honeycomb Core and FGM Face Sheets

This paper presents a mathematical model to investigate the nonlinear dynamic behavior of a high speed rotor-bearing system due to surface waviness with varying number of waves. In the formulation, the contact between rolling elements and inner/outer races are considered as nonlinear springs with nonlinear damping incorporated, which is developed by correlating the contact damping force with the equivalent contact stiffness and contact deformation rate. The equations of motion are formulated using Lagrange’s equation, considering the vibration characteristics of the individual components such as inner race, outer race, rolling elements and rotor. For high speed rolling element bearing supported by a rigid balanced rotor with defective bearings, nonlinear dynamic responses are found to be associated with wave passage frequency and also with the interactive effect of wave passage and inner race frequencies (ω inner ). Results presented in the form of fast Fourier transformation are in agreement with authors’ various experimental results.

Vibration Analysis of High Speed Rolling Element Bearings due to Race Defects

The low frequency vibration transmitted to the body can affect the comfort, performance, and health of humans. In
this paper, the effect of variations in posture and vibration magnitude on the head motion in three translational axes
(fore-and-aft, lateral and vertical) has been studied with a vertical seat vibration. Thirty healthy male subjects were
exposed to random vibration with three vibration magnitudes of 0.4, 0.8, and 1.2 m/s2
rms over the frequency range
of 1–20 Hz. The results are analysed in terms of seat-to-head-transmissibility (STHT) for the head motions in two
seated postures (backrest and leaning forward on table). The measurement of the head motion was made with an
apparatus (bite-bar) specifically developed for this purpose. The measured responses to a single axis seat vibration
have also shown notable cross-axis responses in both vertical and fore-and-aft axes for both postures. The crossaxis fore-aft and vertical STHT responses showed single peak near 5 Hz in both postures. An increasing intensity
of vibration yields a non-linear softening effect in the muscle tension, particularly in the presence of back support,
however, the body stiffens under a greater upper body motion in the forward leaning posture. The combined effect
of the unsupported back and hands support was observed to be more pronounced around the resonance peak in the
forward lean posture.

/pdf/seat-to-head-transmissibility-during-exposure-to-vertical-40vval52h7.pdf

Seat to Head Transmissibility during Exposure to Vertical Seat Vibration: Effects of Posture and Vibration Magnitude

Freight trains run under high service loads during consignment loading and operation so tapered roller bearings are ideally suited to wheel bearing applications. The tapered roller bearings used in the railway industry are of a standard design fixed by the American Association of Railroads regulations. Nowadays rail industry improves the train operating speeds, which means that failure of a bearing will result into a derailment, affecting human lives, network disruption, and damage to the railroad, unplanned maintenance costs, and generating fear in general public about rail transport. So the rail industry has focused on the improvement in maintenance work and improvement in component design. This paper discusses the results of finite element analysis and model analysis of Cartridge Tapered Roller bearing (CTRB). Solid modelling of CTRB has been done using solid works. The CTRB is then discretized using ANSYS software and 3D hexahedral solid elements are used to mesh the components. The effect of vibration modes on the dynamic behaviour and stability of wagon is described. Frequencies up to a range of 100 Hz are considered for mode shapes.

http://ischolar.info/index.php/IJVSS/article/download/185330/172556

Finite Element Analysis of Cartridge Tapered Roller Bearing of Freight Wagon

The present work investigates the effect of a crack on the modal frequency of a draft pad. Initially, the first five mode shapes of a healthy draft pad and the first seven mode shapes of healthy draft gear considering compressed draft pads are determined using the finite element approach. A mathematical model of the draft pad is formulated to predict the effect of the crack on its modal frequency. A semi-elliptical shaped crack is modelled in the lateral and longitudinal direction of the draft pad. It is observed that if the crack lies in the zone of minimum modal displacement, then the frequency drop is minimal, and if the crack lies in the zone of maximum modal displacement, then the frequency drop is significant. Various damage scenarios are simulated by varying the width and aspect ratio of the crack in order to identify its effect on the modal frequency. It is seen that if the aspect ratio is varied while the crack’s width is maintained constant, then the frequency drop is linear, whereas if the crack’s width is varied while the aspect ratio is maintained constant, then the frequency drop is parabolic. This study provides a tool for monitoring exciting frequencies of draft gear and shows how each modal frequency is affected by the crack due to parameters like aspect ratio, crack width, and crack location/orientation.

/pdf/dynamic-analysis-of-draft-gear-and-draft-pad-of-freight-l41gr6lpph.pdf

S. P. Harsha

Papers

Free Vibration Analysis of Sandwich Plate with Honeycomb Core and FGM Face Sheets

Vibration Analysis of High Speed Rolling Element Bearings due to Race Defects

Seat to Head Transmissibility during Exposure to Vertical Seat Vibration: Effects of Posture and Vibration Magnitude

Finite Element Analysis of Cartridge Tapered Roller Bearing of Freight Wagon

Dynamic Analysis of Draft Gear and Draft Pad of Freight Wagon due to Localized Defects using FEM