Nordin Jamaludin

Correlating strain and acoustic emission signals of metallic component using global signal statistical approach

This study clarifies the fatigue properties using global signal statistical approach during the crack initiation stage for metallic component. Strain loading and acoustic emission (AE) signatures are captured simultaneously in the form of signal waves recorded by strain gauge and AE transducer. An initial study was carried out in the laboratory on medium carbon AISI 1045 steel specimens at constant amplitude cyclic loading condition, which lead to the fatigue failure characteristics. This study was carried out to investigate the relationship between strain and AE signals in order to make sure that AE technique also can be used as a detecting and monitoring crack initiation in metallic specimens. To achieve the goal, three different loads were applied on three specimens to capture the differences of the signals. The specific data acquisition systems were used to collect strain and AE signatures. For the purpose of analysis, the method of root mean square (r.m.s) and the kurtosis were used. The r.m.s value was used to quantify the overall vibrational energy content whereas the kurtosis was then used because of its sensitivity to high amplitude events. Based on these statistical approaches, the correlation patterns between both signals are expected to give a meaningful baseline to predict and monitor crack initiation of a metallic specimen.

Acoustic Emission Behavior during Fatigue Crack of API5LX70 Gas Pipeline Steel

This paper present Acoustic Emission (AE) generated during fatigue mechanism of API5LX70 steel which was widely use as gas pipeline materials. Fully reverse (R=-1) constant amplitude fatigue test were done with four different stress amplitudes which were 437.5MPa, 406.25Mpa, 390.6MPa and 359.4MPa respectively. An observation from those tests shows that AE Count gives a significant value during cyclic softening and bauschinger effect. Crack initiation indicated by rapid increase of AE count values at positive peak stress and followed by high AE count values around zero stress which indicate crack closure phenomena. Among all four tests, it was show that AE activity from fatigue test with amplitude of 359.4MPa can be significantly divided into 3 region which correspond to crack incubation stage, microplastic and slip plane formation stage and crack initiation and propagation stage. Further analysis was done by separating AE signals from those 3 regions into 6 different groups. Ten AE signatures from each group were selected to calculate AE RMS and AE kurtosis. Analyses on AE RMS which correspond to overall energy of the signal were useful to indicate the microplastic and slip plane formation stage and crack initiation and propagation stage while AE kurtosis was useful in indicating crack stage including initiation, propagation and closure stage.

Acoustic Emission Study of Corrosion Fatigue and Fatigue for API 5L X70 Gas Pipeline Steel

Acoustic emission is a very important test among non-destructive tests, and it has been applied for the detection of failures in various types of equipment in the petroleum industry, such as pressure vessels, tanks and pipelines. In this study, the effect of pre-existing uniform corrosion on the corrosion fatigue specimen and smooth specimen on fatigue behaviour of API 5L X70 steel pipeline in long life range was investigated by using acoustic emission in fatigue test. The presence of pre-existing uniform corrosion specimen, produces by 4 month immersion in sulphuric acid, H2SO4 (concentration 0.2 ml H2SO4 in 5000 ml deionized water ). Fully reverse (R = -1) constant amplitude fatigue test were done in corrosion fatigue and smooth specimen in different stress amplitudes. It was found that, effect of pre-existing uniform corrosion significantly reduced the fatigue life of the steel pipeline. The correlations of accumulative AE counts for corrosion fatigue higher than fatigue test because of the mechanisms of possible AE sources due to corrosion.

Application of acoustic emission technique to observer the engine oil's viscosity

This paper presents an investigation of the capability of the acoustic emission (AE) technique in the processes of monitoring and detecting the variation of engine oils viscosity via in-situ operation. The investigations were conducted on an 8.5-hp single cylinder of four strokes with a water cooling engine. One single grade engine oils condition has been put to the test; namely, SAE 40 VI 96. The oil condition in the engine was successfully monitored based on the AE signatures generated by the interaction between the piston surface and the layer of the oil during the time that the engine was in operation. The generated AE signatures were captured using an AE wide band transducer that was bonded outside the engine block and located at the lower part of the bottom dead centre (BDC). The captured waveform signatures were then analysed using the MATLAB software. The results of the experimental works show that the statistical analysis parameters including the root-mean-square (rms), maximum amplitude and AE energy values are capable of distinguishing the variant of the viscosity. The AE technique can assist the owner of the engine in determining the engine oils condition before replacing it.

Car Body and Chassis Development of UKM CARevo for Perodua Eco-Challenge 2011

This paper presents the development of the UKM Perodua Eco-Challenge vehicle, CARevo in terms of aesthetic design, novel fabrication of car body and superior chassis design. The objective of the competition was to develop a fuel efficient car which was competent to travel the longest distance using 0.5 liter of RON95 fuel with some rules and regulation verified by the Perodua to be followed. The UKM CARevo was powered by a 660cc fuel injection engine with manual 5-speed transmission with the total of 3450 mm, 1500 mm and 1106 mm for its length, wide and height. Several design such as space frame chassis design, composite bodywork result from fiberglass with resin, aerodynamic design of car body and are the key features that is discussed in this paper.

Karman Vortex Creation Using Cylinder for Flutter Energy Harvester Device

This study presents the creation of a Karman vortex for a fluttering electromagnetic energy harvester device using a cylinder. The effects of two parameters, which are the diameter and the position of the cylinder, were investigated on the Karman vortex profile and the amplitude of the fluttering belt, respectively. A simulation was conducted to determine the effect of the creation of the Karman vortex, and an experiment was performed to identify influence of the position of the cylinder on the fluttering belt amplitude. The results demonstrated that vortex-induced vibration occurred at the frequency of the first natural mode for the belt at 3 cm and 10 cm for the diameter and position of the cylinder, respectively. Under such configuration, an electromagnetic energy harvester was attached and vibrated via the fluttering belt inside the turbulent boundary layers. This vibration provides a measured output voltage and can be used in wireless sensors.

Single-Grade Engine Lubricant: Introduce Viscosity Index Numerical Order (VIno)

Single-grade engine oil viscosity experience changes influenced by temperature and pressure. However, in reality, the viscosity of engine oil is also affected by age and it has been proven in earlier studies through the viscosity model of the UKM Equation (ηUKM). In this mathematical model, the viscosity of the engine oil is manipulated by the factors of temperatue and time. Both of this factors relies fully on laboratory data. Based on this hypothesis, a model of the viscosity which is based on a mathematical model have been developed whereby the technical temperature factor value and technical time factor are obtained through engine oils technical data such as the density, viscosity index and kinematic viscosity; technical parameter displayed in technical statements of every engine oil. This model is named the viscosity model of viscosity index numerical order (ηVIno) and the estimation of viscosity obtained through the ηVIno was found to not exhibit any significant deviation from the actual viscosity of the oil.

Monitoring the Petrol Engine Oil Viscosity: Investigation of the Capability of the Metal Magnetic Memory Technology

An engine lubrication system is one of the main factors which influence engine life span, and it can be easily determined based on the viscosity of the engine oil. The current and common technology for monitoring and the determination of the engine oil viscosity using the oil analysis method is found to be uneconomical and ineffective. On the same vein, this paper presents an investigation of the capability of the Metal Magnetic Memory (MMM) technology in the processes of monitoring and detecting the variation of petrol engine lubricant viscosity via in-situ operation. A few investigations were conducted on a Robin Engine 126 cc EX 13D single cylinder of four strokes with water cooling. One multi-grade engine lubricant oil condition has been put to the test; namely, SAE 15W-40. During the investigation of the petrol engine oil viscosity, the magnetic field signal is captured when the engine oil in-service age is 0 km (fresh oil), 250 km, 500 km, 750 km and 1,000 km, with the crankshaft rotational speed of 2500 rpm at three different locations such as at the Bottom Dead Centre (BDC), oil sump A (engine oil inlet), and oil sump B. The lubrication condition in the petrol engine is successfully monitored based on the magnetic field signatures generated by the interaction between the piston surface and the layer of the lubricant during the time when the engine was in operation. The generated MMM signatures were captured using a type 2 scanning device with two ferroprobe sensors and a length measuring sensor and recorded by the TSC-3M-12 type device. The waveform signatures captured were displayed as length domain signal and then were analysed using the MATLAB software to determine the magnetic field energy (EH). In addition, the real viscosity value at room temperature was determined using the Haake Viscotester 6 L, each time after the magnetic field signal was captured. The results of these studies have shown that the magnetic field energy (EH) is inversely proportional to engine oil viscosity. Finally, the MMM technology can be utilised in promoting economic development and effective planning of the maintenance schedule of the petrol engine oil.

Fatigue Failure Assessment of Metallic Specimens using the Acoustic Emission Technique.

Abstract This paper presents a process to determine the relationship between acoustic emission (AE) signals and the strain signal pattern for estimating material fatigue life. In addition, it establishes the usefulness of AE in predicting the fatigue life of metallic components. This study was carried out to investigate the relationship between the strain and AE signals to ensure that AE can also be used as a tool to predict the fatigue life of metallic specimens. Two types of sensors, i. e., the AE piezoelectric transducer and the strain gauge, were attached to SAE 1045 steel specimens during the fatigue cyclic test when the specimens were under constant loading. Two types of signals were obtained at three different applied loads (6.0 kN, 6.4 kN and 6.8 kN). Both signal types were then analyzed using a statistical model, and the results were used to correlate the fatigue life and AE signals. The fatigue life values were calculated using strain-life models. The correlation between the experimental and predicted values of fatigue life was then established. The results showed that the correlation between the r.m.s. AE values and the calculated fatigue life ranged from 74.0 % to 98.5 %, while the correlation between the kurtosis AE values and the predicted values was found to be between 95.0 % and 99.9 %. These correlation values showed that the AE technique can be used to predict the fatigue life of metallic specimens.

Life Prediction of SAE 1045 Carbon Steel Using the Acoustic Emission Parameter

The competency of acoustic emission (AE) technique in order to predict the fatigue life of SAE 1045 carbon steel was discussed in this paper. The correlation of the AE parameter and the number of cycles to failure of the tested specimens were established via the statistical approach. In this paper, The AE hits were selected as the functional parameter. The fatigue life values were calculated using the strain-life approach of three models; Coffin-Manson, Smith-Watson Topper and Morrow. Both AE and strain signals used in the analysis were captured using the AE sensor and strain gauge that were attached to the specimen during the fatigue test. The results show that the AE technique has a good potential in assessing the fatigue life with the designed H-N curve (AE hits-number of cycles to failure curve).