M. M. Padzi

Fatigue Damage Assessment of the Engine Mount Bracket Using a Statistical Based Approach

Fatigue damage assessment is very important in design process of the component to determine their durability under service loading conditions. In service, the great majority of structures and components are subjected to stress of variable amplitude loading. The purpose of this research is to analyse statistically of two types of strain signals from road loading and compare their effect on fatigue damage of the engine mount bracket. Strain gauges were attached to the engine mount bracket and were connected to the data acquisition set in order to capture the actual strain signals when an automobile was driven on two different road surfaces. The strain signals were then analysed using global signal statistic and integrated kurtosis based algorithm for Z-filter (I-kaz) method. Meanwhile, damage of the engine mount bracket was evaluated using finite element commercial software. From the analysis, it was found that the fatigue damage showed an increment with the respective statistical values of the strain signals.

A statistical based analysis approach on fatigue failure assessment of carbon steel

This paper discussed on an application of the statistical based analysis approach on fatigue failure of carbon steel. A new statistical based method known as Integrated Kurtosis-based Algorithm for Z-filter (I-kaz) and the quadratic mean were used in this fatigue failure assessment. Fatigue tests were performed according to the ASTM E466-96 standard with the attachment of a strain gauge to the tested specimen. Test was performed at a constant loading leading to the collection of strain data throughout the test. A fatigue based data acquisition system was used in this work. All obtained data were analysed using specific software. Fatigue failure behaviour was observed through the strain signal analysis to investigate significant correlation between I-kaz coefficient, root mean square value and the fatigue failure behaviour. It was found that I-kaz coefficient and root mean square value are proportional to life cycle.

Assessment of fatigue behaviour under different loading sequences using signal analysis approaches

Abstract Constant amplitude data obtained from smooth specimens have been used for many years to evaluate the fatigue life of components. However, most of the loadings used in real applications are variable or random. In this research, three types of loading were applied – constant, low–high (LH), and high–low (HL) loading sequences. This paper presents an assessment of the fatigue behaviour under these three types of loading, and the effects of each loading on the fatigue behaviour as well as on life are highlighted. Fatigue tests were performed according to ASTM E466-96 standard with a strain gauge attached to the specimen being tested. AISI 1045 carbon steel was used as material for this tests due to its wide applications in the automotive industry. Fatigue tests were carried out at a constant, LH, and HL loading stresses at a sampling frequency of 8 Hz. A set of data acquisition system was used to collect the fatigue strain signals. All signals obtained were analyzed using two signal-processing approaches – the power spectral density (PSD) method and the integrated Kurtosis-based algorithm for Z-filter (I-kaz) technique. Fatigue behaviour was observed from the initial until the last stage of the fatigue test. The PSD peak values and I-kaz coefficients were determined to explain and describe the behaviour of fatigue damage. Both results are comparable in the fatigue damage assessment.

Fatigue Characteristics of 3D Printed Acrylonitrile Butadiene Styrene (ABS)

Recently, the use of 3D printer technology has become significant to industries, especially when involving the new product development. 3D printing is a technology, which produces the 3D product or prototype using a layer-by-layer technique. However, there becomes less research on the mechanical performance of the 3D printed component. In the present work, fatigue characteristics of 3D printed specimen have been studied. Acrylonitrile butadiene styrene (ABS) has been chosen as a material research due to its wide applications. Two types of specimen used, which is the 3D printing and moulding specimens. Fused deposition modelling (FDM) technique was used to produce the specimens. The dog bone shape part was produced based on ASTM D638 standard and the tensile test has been carried out to get the mechanical properties. Fatigue test was carried out at 40%, 60% and 80% of the tensile strength. The moulded part shows higher fatigue cycles compared to 3D printed part for all loading percentages. Fatigue lives for 40%, 60% and 80%, were 911, 2645 and 26948 cycles, respectively. The results indicated that 3D printed part has a lower fatigue life, which may not suitable for industrial applications. However, the 3D printed part could be improved by using various parameters and may be introduced in low strength application.

Effect of post weld impact treatment (PWIT) on mechanical properties of spot-welded joint

This paper focuses on the study of improvement for spot welding on the tensile shear and hardness by applying post weld impact treatment (PWIT) on the welded joint. The main objective of the research is to characterize and improve the mechanical properties of the joint. The method of PWIT used on the welded joint was Pneumatic Impact Treatment (PIT). The concept of PIT on spot welding is that it improves the mechanical properties of the welded zone. The working sample was undergoing a resistance spot welding of joining two similar in dimension and material of a steel plate before treated. The dimension of both plate are 110 mm × 45 mm × 1.2 mm and the material used were low carbon steel (LCS). All the welded samples were tested for its mechanical properties by performing the tensile-shear and hardness test. Tensile-shear test was conducted on the spot welded, both treated and as-welded samples using crosshead speed of 2 mm/min, while hardness test was performed using 1kgf load via Vickers hardness indente...

Characterization of Biaxial Fatigue by Using Strain Energy Density Approach for Steel

This research discussed on the determination of the appropriate fatigue damage parameter to predict the fatigue life when material subjected to the biaxial loading condition with the consideration of the energy dissipated. Servo-hydraulic machine is used for the constant amplitude cyclic testing on smooth solid mild steel. The results showed that in the low cycle fatigue, the total strain energy density can represent the accumulative of fatigue damage and characterize on the damage parameters. The relationship has been proposed which the data satisfactorily correlated for the R2 is 0.8656. In addition, the hysteresis loop represent the area under the graph was the energy stored in the material during the loading and unloading condition. Hence the circumstances showed the deformation process governing the nucleation and propagation of fatigue cracks associated with the energy dissipated.

Fatigue Behaviour Monitoring of an AISI 1045 Carbon Steel using the Statistical-Based Z-Notched Approach

Abstract In this work, three percentages of constant loading are used for fatigue failure assessment. Fatigue behaviour under these three percentages of constant loadings is analyzed by using a new statistical-based approach known as integrated kurtosis-based algorithm for Z-notch filter (I-kaz). Fatigue tests were performed according to ASTM E466-96 standard with a strain gauge attached to the specimen being tested. A fatigue test was conducted under three loadings between 600–700 MPa and at a frequency of 8 Hz. A set of data acquisition systems was used to collect the fatigue strain signals. The I-kaz technique, which provides an I-kaz coefficient and a three-dimensional (3D) graphic, was used to describe and to evaluate the fatigue failure activities. The trends of I-kaz coefficients and of 3D graphics were compared to explain the fatigue damage induced by the three loadings.

Fatigue Damage Assessment Correlating with I-Kaz Coefficient

This paper describes the correlation between fatigue life with the I-kaz coefficients. Fatigue tests were performed according to the ASTM E466-96 standard with a strain gauge attached to the specimen being tested. AISI 1045 carbon steel was used as the material for this test due to its wide applications in the automotive and machinery industry. Fatigue tests were carried out at several constant loading stresses of 610 MPa, 650 MPa and 690 MPa at the sampling frequency of 8 Hz. A set of data acquisition system was used to collect the fatigue strain signals. The integrated Kurtosis-based algorithm for Z-filter (I-kaz) technique had been used to find the I-kaz coefficient. The I-kaz coefficient is found to have a good correlation with fatigue life, other than can represent fatigue damage.

Fatigue Life Assessment of Aluminium Alloy 6061 Specimen Using Signal Analysis Approach for Automotive Components

This paper is aimed to investigate the fatigue assessment of aluminium alloy 6061specimen, one of the widely used aluminium alloys in the production of mechanical components. The alloy possesses the ability of critical failure caused by fatigue when they are subjected to dynamic responses in automotive-type components. The specimens were prepared according to the ASTM E606 and ASTM E1820 standards which were then subjected to two types of cyclic loading amplitude modes namely constant amplitude and random amplitude. The effort is initiated by implementing fatigue data editing approach for random amplitude signal, the conventional method, the finite element method (FEM) and fatigue assessment determination through the statistical method of root mean square (r.m.s) and kurtosis. The input and edited signal acquired will be analyzed for the prediction of the fatigue damage based on the strain model approaches, i.e. Coffin-Manson, Morrow and SWT. From the results obtained, both edited and non-edited signals load display the same amount of fatigue damage to consequently decrease the analysis duration. In addition, the FEM was found to be the best approach for estimating the fatigue life. This research has finally revealed that the higher cyclic load amplitude will only diminish the fatigue life of a specimen. Furthermore, this fatigue assessment study will look forward to improve structural engineering development in monitoring components and consequently access the damage prediction variable which could later be implemented to the manufacturing industry.

Experimental Analysis of an Instrumented Charpy Impact Using Signal Processing Approach

The dynamic responses of the standard charpy impact machine are experimentally studied using the relevant data acquisition system in order to obtain the impact response. For this reason, strain gauges were connected to the data acquisition set and it was then attached to the charpy striker for the signal collection. Aluminium 6061 and low carbon steel 1050 were used for extracting strain responses on the striker during the testing. In this work, the power spectrum density (PSD) approach was then used for the energy based observation and a signal was converted from the time domain to the frequency domain using the fast Fourier transform (FFT) method. Comparison between experimental findings with related parameters such as of different materials, strain signals pattern, I-kaz, were finally correlated and discussed. It was found that the modulus of elasticity were proportional to the energy absorbed, strain signals amplitude and PSD. Finally, it is suggested that the properties of materials and the impact signals pattern is suitable to be analysed using the signal processing approach.