Investigation of crack in beams using anti-resonance technique and FEA approach

Abstract

Purpose In the case of machines, structures and assemblies, the crack generation and propagation is becoming a great concern, especially in airplane wings, turbine blades and such other applications. This is because these parts are very large in size and the crack size is very small, i.e. in microns. Hence, there is an important need to locate the crack and to find its severity before it starts to propagate and also to detect these parameters by on-site non-destructive testing methods. This paper aims to develop and test the methodology to locate an unknown single open crack in steel cantilever beam along with its severity. Design/methodology/approach This study covers analytical, numerical and experimental analysis for healthy and cracked beams. Vibration-based approach and finite element analysis (FEA) approach is used for analytical and numerical study respectively. Own designed and dedicated experimental set-up is used for testing purpose along with fast fourier transform analyzer. An anti-resonance technique is used to locate and to find the severity of unknown crack. The statistical approach helps to validate the results. Findings The comparison of the natural frequency of healthy and cracked steel cantilever beam shows that the crack in the beam reduces its natural frequency. The accuracy of results is achieved by finding actual density and Young's modulus of steel specimen under consideration. It is helpful to verify the health of the non-cracked beam by applying dye testing. The study of natural frequency and anti-resonance gives the location of crack and its depth also. The FEA approach proved to be an important tool for numerical analysis of cracked beam. Research limitations/implications The research is limited to steel material and surface cracks only. Practical implications Practically, this study highlights how to locate a surface crack in steel beam along with its depth, i.e. severity with great accuracy. Identification of the factors such as location and depth of a crack provide the severity of damage in airplane wings, turbine blades, bridges and many more, and thereby, it helps in safety at working vicinity. Social implications The identification and solutions of current research helps to predict the operational life of machine elements such as airplane wings, turbine blades, bridges and many more, and thereby, it helps in the safety of people in working vicinity of such structures. Originality/value The work presented, is based on original research and experimentation. This work is valued contribution in the field of methodologies applied for fault detection in structures and also determining its correctness by numerical and experimental work.

Behavior of cracked Euler–Bernoulli beam and inverse problem for assessing crack severity

“…The crack propagation in machines, structures, and assemblies such as airplane wings, turbine blades, and other applications has a great interest to predict the operational life for machine components; then it is very important to identify the severity of crack before it starts to propagate. 22 Hence, inverse problem for detect crack severity, that is, crack depth prediction has been included in the study of crack severity. In this study, similar to Bhaurkar and Thakur, 22 results of FEA frequency ratio for the first mode of bending vibration for the cracked simply supported beam versus crack depth ratio are plotted as shown in Figures 28-30.…”

“…22 Hence, inverse problem for detect crack severity, that is, crack depth prediction has been included in the study of crack severity. In this study, similar to Bhaurkar and Thakur, 22 results of FEA frequency ratio for the first mode of bending vibration for the cracked simply supported beam versus crack depth ratio are plotted as shown in Figures 28-30. It is observed that there is change in FEA frequency ratio as crack depth ratio changes where FEA frequency ratio decreases as crack depth ratio increases.…”

Performance assessment of various seismic resistant systems for a multistory structure in different seismic zones of Bangladesh

“…Previous studies also found that the upper sections of the structures are the most crucial as they are affected by both the soil stiffness, probable ground liquefaction characteristics (Wang et al , 2019) and structural motions (Rahnavard et al , 2018; Radkia et al , 2020; Etedali et al , 2020; Lanzi and Luco, 2018; Tsai et al , 2019). So, to predict these damage due to ground motion, various analytical approaches are adopted, such as a simplified single-degree-of-freedom system (Adam et al , 2004; Miranda and Akkar, 2003; Williamson, 2003; Takizawa et al , 1980), use of finite-element analysis to measure the structural response (Williamson, 2003; Takizawa et al , 1980; Bhaurkar and Thakur, 2019) and recently emerged incremental dynamic analysis (Zareian et al , 2010; Medina et al , 2006; Vamvatsikos and Cornell, 2002; Zareian et al , 2007; Moradipour et al , 2013). Dynamic analysis should have been carried out to determine the structure's nature and complete response against base excitation (Ahamad and Pratap, 2020).…”

Low velocity impact study of a sandwich beams using Ritz method and finite element modelling

“…Impact loading simulation on a construction safety helmet over a head form is carried out by Khan and Sonawane (2019) using 3D FE simulations. Bhaurkar and Thakur (2019) carried out a FE analysis for the investigation of crack in the beams. Barour and Zergua (2020) simulated reinforced concrete beams strengthened in shear with carbon fiber-reinforced polymer sheets under four-point bending using ANSYS software.…”