Shahrum Abdullah

• National University of Malaysia

The cultural adaptation process manifested by students enrolled in the double-degree programme at the Universiti Kebangsaan Malaysia (National University of Malaysia) and the University of Duisburg-Essen (UDE) in 2009 to 2010 was investigated in this study. The concept of resilience was also examined using two standard psychometric tools, namely, t...

One of the major concerns of the Engineering Accreditation Council (EAC) is the need for an effective monitoring and evaluation of program outcome domains that can be associated with courses taught under the Mechanical Engineering program. However, an effective monitoring method that can determine the results of each program outcome using Bloom’s T...

Universiti Kebangsaan Malaysia (UKM) is a research university that continuously undergoes an audit and accreditation process for the management of its courses. The Faculty of Engineering and the Built Environment (FKAB) is subjected to such processes, one of them is the auditing conducted by the Engineering Accreditation Council (EAC), which gives...

The main objective of this research paper is to examine the fatigue life of the R260 material specimen under uniaxial fatigue testing. Three specimens were selected to evaluate the value of ultimate tensile strength (UTS), ensuring a similar number using UTM, specifically below 250 kN. The specimens shape designed in requirement standard ASTM E8 fo...

This study aims to characterize the statistical durability under random strain loads for fatigue reliability prediction of a heavy leaf spring. Characterizing random data involving a probabilistic approach needs to be addressed in terms of defining applicable distribution as the strain data are random cyclic loading that leads to fatigue damage. In...

This aim of this paper is to characterise the strain-based fatigue life data in time-domain using the newly modelled running-reliability technique that considers the load sequence effect. Current established conventional strain life models do not consider dependence for fatigue life of low or high amplitudes, on which with occur first in the load h...

The main objective in this paper is to determine the fatigue life of light rail transit in urban network through bulk specimens. It has involve regards the fatigue failure analysis in simulation to estimate the fatigue life of UIC60 rail profile as steel with using specimen of bulk in accordance standard of ASTM E466-15. The type of tensile strengt...

This study proposed wavelet-based approaches to characterise random vibration road excitations for durability prediction of coil springs. Conventional strain-life approaches require long computational time, while the accuracy of the vibration fatigue methods is unsatisfactory. It is therefore a necessity to establish an accurate fatigue life predic...

The behaviour of the steel bar in concrete under cyclic loading has been evaluated using magnetic flux leakage associated with acoustic emission monitoring technique. Visual observation was used to observe the deformation of the beam under cyclic loading. The sensors of metal magnetic memory were scanned in the middle of the beam at a distance of 3...

This study presents a fatigue reliability assessment of a vehicle coil spring based on random road load conditions for fatigue life characterisation. Fatigue life data characterisation was carried out to accelerate the durability analysis by retaining the higher amplitude cycles in the original strain signals and thus indicate the fatigue damage. T...

The aim of this paper is to characterize the fatigue under various random strain loads that consider the effects of cycle sequence conditions. Due to the frequent exposure of fatigue damage to a leaf spring, the fatigue life calculation needs to consider a load cycle sequence effect. A finite element analysis is performed to determine the critical...

The purpose of this paper is to determine the best dimple core design for metal sandwich panels by investigating the various critical criteria and core design parameters using the fuzzy-hybrid multi-criteria decision-making tool. The structural integrity of a sandwich panel depends on the core design and significantly affects the bonding strength....

This paper presents a modified fatigue life model of the Basquin equation using the stress parameter of the magnetic flux leakage signal. Most pipeline steels experience cyclic loading during service and the influence of the load history makes assessing fatigue behaviour more difficult. The magnetic flux leakage signal’s response to a uniaxial cycl...

The aim of this paper is to characterise the fatigue reliability for various random strain loads under extreme value distribution while considering the cycle sequence effect condition in fatigue life prediction. The established strain–life models, i.e., Morrow and Smith–Watson–Topper, considered a mean stress effect and strain amplitude; neverthele...

This research paper reviews the recent works on the rolling contact fatigue of rail wheels. The topic covered includes the mathematics equations of rail-wheel contact stress and fatigue, RCF defects in the rail, the development of cracks, and the strategies used to reduce the rate of RCF defects. Therefore, the main understandings of RCF as they cu...

This study proposes acceleration-strain conversion model for coil spring in fatigue-durability prediction by considering the load sequence effect. Established models were inaccurate in fatigue life prediction when the load sequence effect was considered. Therefore, signal processing technique was applied to retain the load sequences in the simulate...

The aim of this study was to determine the relationship between fatigue crack length, a, the number of cycles, N, the magnetic flux gradient intensity, dH/dx and the stress ratio, R. Fatigue crack growth tests were performed using a constant tensile load amplitude on SAE 1045 steel in the form of single-edge cracks. Stress ratio values of 0, 0.1, 0...

Vibration fatigue characteristics are critical for rotating machinery components such as turbine rotor blades. Lattice structures are gaining popularity in engineering applications due to their unique ability to reduce weight and improve the mechanical properties. This study is an experimental investigation of octet-truss lattice structure utilizat...

This paper aims to investigate the effects on metal sandwich panels with different dimple core designs using four-point bending simulation under constant and variable amplitude loading. A core design with cavity and porosity in the body structure was found to reduce the panel structural integrity. This would lead to unstable bonding between the pan...

The aim of this article is to determine the relationships between the essential criteria for the performance of sandwich panels and various alternative hemispherical core designs using a hybridisation technique within the multi-criteria decision-making method. A major reduction in core density reduced the structural integrity of the metal sandwich...

This study aims to investigate the delamination effect of a metal sandwich panel using a four-point bending simulation under continual spectrum loading. The most recent core designs of the sandwich panel have a cavity that can increase vulnerability in terms of bonding strength under constant cyclic loading. The sandwich panel is simulated under co...

Purpose This paper aims to assess the fatigue life characteristics of vehicle coil spring under random strain load in the time domain. Cyclic random road loads caused fatigue failure for automotive components during their operating condition. . Design/methodology/approach The coil spring model is developed through finite element analysis software....

The aim of this study is to characterise the fatigue life data of multiaxial strain signals of an automobile suspension coil spring under various road load condition. The automobile coil spring experiences cyclic load due to the variation of road conditions, resulting in compression-tension loads, and providing a direct shear force and a torsion in...

This study aims to determine the appropriate frequency domain methods for durability predictions of lower suspension arm based on real-life random vibration data. In frequency domain, the power spectral densities (PSD) of the vibration signals were obtained and then analysed using three PSD cycle counting models, including the Lalanne, Dirlik and N...

This paper presents a real-time classification of road class based on the measured spring strain signals through Hilbert-Huang transform (HHT). Road profile measurement is an important element for vehicle ride and fatigue assessments, but the actual measurement procedures are complex. In this analysis, a finite element model was used to obtain the...

The aim of this paper is to investigate the mechanical effects of three different core designs of solid plate, honeycomb, and dimple surface sandwich panel subjected to static and fatigue loading conditions. The performance of sandwich panel is important and dependent on the main core material and design. The higher density reduction on core struct...

This paper presents the delamination effect on the metal sandwich panel of AR500 with magnesium alloy of AZ31B as main core under constant spectrum loading. Recent sandwich panel mostly dealt with static loading, with least research under constant cyclic loading while also having cavity element on its structure, which made them exposed to the catas...

The aim of this paper is to investigate the modal characteristics and harmonic response of two lattice-based configuration called octet truss and cubic lattice in order to find out their suitability for use in turbine blades and other high speed rotating components. Solid model is used as reference. Lattice structures offer great flexibility and op...

This review analyses the trends and future opportunities of additive manufactured lattice structures and its fatigue behaviour. Additive manufacturing, a layer-by-layer process to fabricate components offers wide opportunities to produce complex lattice structures compared to conventional manufacturing techniques. The interest in lattice structure...

This paper presents the determination of a suitable probability function for fatigue-related reliability assessment of automotive coil springs under various road excitations using maximum likelihood estimation (MLE). The fatigue-related reliability assessment is a critical element for determining the component warranty period. The fatigue lives of...

This paper aims to evaluate the modal frequency responses of suspension lower arm subjected to random road excitations for fatigue life prediction. Traditional time-domain approaches for durability prediction require long signals and computationally heavier. Hence, frequency domain method was utilised to assess the fatigue life of suspension lower...

This paper presents fatigue life determination of automobile coil spring subjected to variable amplitude loading by considering the loading sequence effect. Fatigue failure of automobile coil spring is common occurrence that is subjected to random loading due to road conditions. Load sequence effect was found to have more significant effects in the...

In reality, damage in the reinforced concrete structure under fatigue causes poor performance under service loading. Hence, this study aims to investigate the acoustic emission characteristics of the reinforced concrete beam subjected to fatigue loading at different sensors. Laboratory experiments were performed on the 150 mm × 150 mm × 750 mm rein...

This paper presents the development of a multiple linear regression based on stress ratio and applied load approach, assessed via thermodynamic entropy generation. Entropy generation as an early detection method that enables researchers to discover temperature evolution caused by dissipated plastic energy if the material experienced fatigue load. T...

This paper aims to characterise the multiaxial strain loading signal in order to assess the durability of the coil spring in the time–frequency domain. Coil spring experiences vertical axial loading, direct shear force, and torsion during movement when subjected to cyclic loading. The experiment was set to capture random strain signal in the differ...

This study on fatigue failure based on the magnetic flux gradient, dH(y)/dx, mostly focuses on the identification of high stress zones, crack propagation monitoring and the characterisation of dH(y)/dx intensity in the crack areas. The main objective of this study was to determine the relationship between fatigue crack growth parameters, dH(y)/dx,...

This paper aims to assess the fatigue reliability of random loading signals of a suspension coil spring using probabilistic approaches. Strain time histories were acquired while the car was travelling on different road conditions (i.e., in a rural area, in an industrial area, on a university campus, on a highway and on a newly constructed road). Fa...

The aim of this paper is to assess the stress concentration zone (SCZ) of a circular smooth specimen at an early stage. Following the detection of the stress concentration zone, the specimen residual life was calculated and compared to the experimental result. Uniaxial loading on the servo-hydraulic testing machine was used for the laboratory testi...

This study concerns the behaviors of stresses distributed on a sandwich metal panel using high-strength steel (HSS) as faces and magnesium alloy (AZ31B) as core materials via simulation analysis. The combination of the sandwich metal panel offered good potential to reduce the vehicle weight, reduce the excessive fractures, and improve the energy ab...

This paper investigates the high stress concentration zone for fatigue crack estimation on the damaged tower crane pulley by measuring magnetic flux leakage. Fatigue crack analysis is important to prevent any component failure that could harm workers. Precautions must be taken to locate the possibilities of failure region on a tower crane pulley. F...

The armoured vehicle uses a special solid steel that has a heavy vehicle ratio which causes the performance to decrease after being triggered by high velocity impact bullet on rescue missions thus experiencing the phenomenon of fatigue and unstable crack growth flow. In this study, an investigation on crack growth behaviour was carried out for sand...

This study aims to investigate the characteristic of the random strain load signal in the time domain to predict durability of the lower arm. Cyclic loading on the suspension arm of vehicles leads to fatigue damage. The suspension arm is subjected to random variable amplitude loading due to different road conditions. Strain load signal data from a...

This paper presents the effect of sandwich panel with two types of dimple core surface and solid plate core on its ballistic properties and strength . The current core such as foam, honeycomb, and lattice cores have cavity and porosity on its structure which made them vulnerable to catastrophic failure due to high impact. This paper aims to enhance...

s The purpose of this study is to develop an acceleration-strain conversion model that considers torsional strain and spring curvature effects in inducing strain for a suspension coil spring. Measurements of strain–time histories at the coil spring are limited by complex geometry and insufficient workspace. This condition increases the demand for s...

This paper aims to assess the effective strain damage (ESD) model with a durability analysis of an automobile coil spring under consideration of the load sequence effect. Conventional strain-life models such as Coffin-Manson, Morrow and Smith-Watson-Topper are insufficient in predicting fatigue life under the consideration of the load sequence effe...

This paper investigates the adhesive effect between the surface layer of sandwich panel with three different core surface configurations by using a peel simulation approach. The sandwich panels with cavity on the core structure can potentially be highly vulnerable to debonding phenomenon when subjected to extreme loading. The three-dimensional sand...

This paper presents clustering of automotive spring fatigue life for failure classification based on K-means approach. For safety promotion of buses, fatigue life prediction of the spring is needed to be classified for maintenance. In this analysis, the strain signals of a heavy vehicle leaf spring were collected from two common roads and analyzed...

This study aims to compute low-frequency energy with Hölder singularities in vibration signals of suspension system to predict the durability of coil spring. High frequencies in vibrations often had minimal contribution towards fatigue damage due to low amplitude range and thus induce errors in energy analysis of vibration signals. Since traditiona...

This study presents the temperature evolution of dual-phase steel in the prediction of the fatigue crack growth rate under block spectrum loading. The degradation coefficient that can be determined from the degradation-entropy generation theorem can be obtained based on the relationship between entropy generation and crack growth. The fatigue crack...

This review outlines the evolution of sandwich panels based on recent work and older sources, focusing on the trends concerning sandwich panel achievements and applications, core materials, core designs, types of failure mechanism and factors which contribute to the failure of sandwich panel. The review begins with an extensive discussion highlight...

This paper aims to assess the fatigue reliability associated for determining the fatigue life characteristics under random strain loads from various road load conditions. Fatigue failure for automotive components is mainly due to the random loads during the operating condition. However, there are still limited studies to associate fatigue reliabili...

This study aims to establish a fatigue life predictive model based on multifractality of road excitations using neuro-fuzzy method to assess the durability of suspension spring. Traditional durability analysis in time domain is complicated and time-consuming due to the needs of large data amount. Thus, it is an idea to adopt an adaptive neuro-fuzzy...

Active damage such as crack initiation owing to cyclic loading in reinforced concrete beams is a pivotal global phenomenon. This damage is because the crack initiation is slowly generated in the structure and cannot be observed visually. As the cyclic load progresses, the cracks need to be classified. This paper presents the prognosis of damage int...

The metal magnetic memory (MMM) method is highly effective in assessing the extent of early damage, such as fatigue crack in ferromagnetic components due to the existence of stress concentration zones (SCZs). However, there are limited studies on the relationship between the magnetic signal parameter in predicting the fatigue life of ferromagnetic...

This paper explores and analyses how reinforced concrete beams, can be restored and repaired after sustaining damage from monotonic loading. Epoxy resin was used to repair the beams. By employing a technique known as the “acoustic emission (AE)” technique, the damage sustained by the beams under monotonic loading can be evaluated. The reference bea...

The aim of this study is to identify the issues that arise when measuring a strain signal in order to characterise fatigue failure. In traditional methods, acquisition of a strain signal is constrained due to the presence of errors, time-consuming process and associated high cost. In this study, a new method for generating strain signals based on c...

This research recognizes the impact of lower cycle amplitude discharge on fatigue failure. Here, the strain data were measured at a lower arm when the vehicle was driven at a particular speed on different road surfaces. Thereafter, the strain data in a time domain was transferred to the time-frequency domain for determining the wavelet-based signal...

Purpose The objective of this paper is to identify suitable lattice structure patterns for the design of porous bone implants manufactured using additive manufacturing. Design/methodology/approach The study serves to compare and analyse the mechanical behaviours between cubic and octet-truss gradient lattice structures. The method used was uniaxia...

This review analyses the design, mechanical behaviors, manufacturability, and application of gradient lattice structures manufactured via metallic additive manufacturing technology. By varying the design parameters such as cell size, strut length, and strut diameter of the unit cells in lattice structures, a gradient property is obtained to achieve...

The brazing of steel and aluminium alloy using low melting point aluminium based fillers has been extensively studied and the technique has been used in many industries, especially the automotive industry. The strength and failure mode of AR500 steel and AA7075 aluminium alloy brazing joint using the Al-Si-Zn filler metal will be measured and calcu...

Purpose A tower crane mainly ensures the success or efficiency of building construction. Fatigue crack analysis is important for tower crane components to prevent any accidents to workers in construction sites caused by component failure and to ease the maintenance or replacement of failed components. This work aimed to characterise the damage of f...

This paper presents the ballistic performance of the joining lightweight metal laminated panel consists of high strength steel and aluminium alloy for armoured vehicle application. Composite laminates trend in military industry present excellent performance in terms of lightweight material due to the improvement vehicle manoeuvrability, without sac...

This paper discusses the determination of the optimum decomposition level by using the discrete wavelet transform (DWT) method for an automobile suspension system. The DWT method has been widely adopted in signal processing analyses. For the purpose of this study, a car was driven on two types of road conditions: highway and bumpy. Strain signals w...

This paper presents a mathematical model to estimate strain-life probabilistic modeling based on the fatigue reliability prediction of an automobile coil spring under random strain loads. The proposed technique was determined using a probabilistic method of the Gumbel distribution for strain-life models of automobile suspension systems. Strain sign...

This paper presents the assessment of fatigue crack growth rate for dual-phase steel under spectrum loading based on entropy generation. According to the second law of thermodynamics, fatigue crack growth is related to entropy gain because of its irreversibility. In this work, the temperature evolution and crack length were simultaneously measured...

This paper presents the optimization of spring fatigue life associated with suspension system parameters using the design of experiment approach. The effects of suspension parameters on spring fatigue life were analyzed because this process can improve spring fatigue life from a distinct perspective. A quarter car model simulation was performed to...

This paper presents the optimisation of spring fatigue life based on an artificial neural network (ANN) architecture and particle swarm optimisation algorithm (PSO) using ISO 2631 vertical vibration as input. The road-induced vibration of a ground vehicle caused the spring to fail due to fatigue and human discomfort. Hence, there is a need to model...

This paper presents a regression analysis of uniaxial and multiaxial fatigue life for automobile coil spring under various road excitations. Coil spring is a suspension component with complex geometry and shear loading which is applied during operating conditions. Hence, uniaxial strain measurement for durability assessment of coil spring is insuff...

This work focuses on the investigation to evaluate a material parameter, namely a contraction value ψ, at failure in estimating the fatigue life of ferromagnetic steel based on magnetic metal memory method. It begins with specimen preparation made from mild carbon steel and it was machined as specified in the ASTM E467-01 standard. These cyclic tes...

Purpose – The purpose of this paper is to analyse fatigue-life prediction based on a reliability assessment for coil springs of vehicle suspension systems using different road excitations under random loading. Design/methodology/approach – In this study, a reliability assessment was conducted to predict the fatigue life of an automobile coil spring...

Purpose This study aims to determine the reliability assessment based on the predicted fatigue life of leaf spring under random strain loading. Design/methodology/approach Random loading data were extracted from three various road conditions at 200 Hz using a strain gauge for a duration of 100 s. The fatigue life was predicted using strain-life ap...

This paper presents a predictive model for fatigue crack growth under loading sequences. Several parameters had been quantified mainly under variable amplitude loading due to its peculiarities. The applicability of the crack closure model was studied to predict the fatigue life span resulting from the continuous effect of loading blocks. The API gr...

In this study, numerical results are conducted to determine the deformation mode of foam filled double circular tubes, namely; half foam filled double circular tube (FD), and full foam filled double circular tube (DD) under oblique loading. To validate the simulation and experimental results, two-parameter Weibull probability distribution was used....

This paper presents the evaluation of the automobile coil-spring strain-displacement relationship for strain signals generation and fatigue life predictions. The development of a strain and spring vertical displacement relationship is significant because measuring vehicle wheel displacements and forces are complex and costly. Hence, there is a need...

Purpose The purpose of this paper is to present the durability analysis in predicting the reliability life cycle for an automobile crankshaft under random stress load using the stochastic process. Due to the limitations associated with the actual loading history obtained from the experimental analysis or due to the sensitivity of the strain gauge,...

Purpose The purpose of this paper is to present the application of Hilbert–Huang transform (HHT) for fatigue damage feature characterisation in the time–frequency domain based on strain signals obtained from the automotive coil springs. Design/methodology/approach HHT was employed to detect the temporary changes in frequency characteristics of t...

The aim of this paper is to determine design configurations of gradient lattice structures through biomimicry for lightweight additive manufactured part designs. Additive manufacturing has led to a better future in the manufacturing field. The capability to manufacture complex models is now possible through additive manufacturing. It is now possibl...

In this paper, probabilistic analysis on the fatigue crack effect was investigated applying the Metal Magnetic Memory (MMM) method, based on Self-Magnetic Leakage Field (SMLF) signals on the surface of metal components. The precision of MMM signals is essential in identifying the validity of the proposed method. The tension-tension fatigue test was...

The aim of this paper is for classification for fatigue feature extraction parameters based on road surface response using the artificial neural network (ANN) technique. It is important for classification of the fatigue damage of automotive suspension as it is considers the random strain loading from the road surface contributed from complex variab...

This paper presents the computational-based ballistic limit of laminated metal panels comprised of highstrength steel and aluminium alloy Al7075-T6 plates to necessitate a weight reduction of 25% in the existing armour steel plate using three different joining materials. Numerical models of the triple-layered panels were developed using the commerc...

This paper presents the fracture behaviour of magnesium alloy (AZ31B) with the reinforcement of carbon-nanotube (CNT) and lead subjected ballistic impact. Magnesium alloys are material that can absorb impact energy, however the absorption energy can be increased with the alloy reinforcement with nano-partial. This paper leads to two parts which are...

This paper presents the analysis and modeling of predicting fatigue lifetime based on the Markov Chain model. Random factor is the main contributor to the prediction of fatigue lifetime. These random factors give an appropriate framework for modeling and predicting a lifetime of the structure. The Markov Chain model was used to predict the probabil...

This paper presents the effect of laminated aluminium-steel panel with different configurations in a high-speed impact test. Layering aluminium plate with high strength steel has become an interest in reducing the overall density of armour vehicle body while improving the ballistic resistance. Different layering configurations differ in laminated p...

The strain signal of an automotive leaf spring component is analysed for fatigue life prediction and characterisation. This study aims to investigate the behaviour of fatigue strain signal based on fatigue life relative to a probability distribution function and a global statistical parameter. The captured data were measured for 150 s at a sampling...

The joining of aluminium alloys to steels has been extensively studied, especially in the automotive sector. However, aluminium alloys are known to be difficult to join with steels when methods involving fusion welding are used because of the hot cracking problem. Hence, a high-strength joint between these dissimilar metals would be of benefit espe...